Author: Shellinfo

manpage less

LESS(1) General Commands Manual LESS(1)

NAME

less – opposite of more

SYNOPSIS

       less -?
       less --help
       less -V
       less --version
       less [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
            [-b space] [-h lines] [-j line] [-k keyfile]
            [-{oO} logfile] [-p pattern] [-P prompt] [-t tag]
            [-T tagsfile] [-x tab,...] [-y lines] [-[z] lines]
            [-# shift] [+[+]cmd] [--] [filename]...
       (See the OPTIONS section for alternate option syntax with long option names.)

DESCRIPTION

       Less  is a program similar to more (1), but it has many more features.  Less does not have to read the entire input file before starting, so with
       large input files it starts up faster than text editors like vi (1).  Less uses termcap (or terminfo on some systems), so it can run on a variety
       of  terminals.   There  is even limited support for hardcopy terminals.  (On a hardcopy terminal, lines which should be printed at the top of the
       screen are prefixed with a caret.)

       Commands are based on both more and vi.  Commands may be preceded by a decimal number, called N in the descriptions below.  The number is used by
       some commands, as indicated.

COMMANDS

In the following descriptions, ^X means control-X. ESC stands for the ESCAPE key; for example ESC-v means the two character sequence "ESCAPE",
then "v".

h or H Help: display a summary of these commands. If you forget all the other commands, remember this one.

SPACE or ^V or f or ^F
Scroll forward N lines, default one window (see option -z below). If N is more than the screen size, only the final screenful is disâАР
played. Warning: some systems use ^V as a special literalization character.

z Like SPACE, but if N is specified, it becomes the new window size.

ESC-SPACE
Like SPACE, but scrolls a full screenful, even if it reaches end-of-file in the process.

ENTER or RETURN or ^N or e or ^E or j or ^J
Scroll forward N lines, default 1. The entire N lines are displayed, even if N is more than the screen size.

d or ^D
Scroll forward N lines, default one half of the screen size. If N is specified, it becomes the new default for subsequent d and u comâАР
mands.

b or ^B or ESC-v
Scroll backward N lines, default one window (see option -z below). If N is more than the screen size, only the final screenful is disâАР
played.

w Like ESC-v, but if N is specified, it becomes the new window size.

y or ^Y or ^P or k or ^K
Scroll backward N lines, default 1. The entire N lines are displayed, even if N is more than the screen size. Warning: some systems use
^Y as a special job control character.

u or ^U
Scroll backward N lines, default one half of the screen size. If N is specified, it becomes the new default for subsequent d and u comâАР
mands.

J Like j, but continues to scroll beyond the end of the file.

K or Y Like k, but continues to scroll beyond the beginning of the file.

ESC-) or RIGHTARROW
Scroll horizontally right N characters, default half the screen width (see the -# option). If a number N is specified, it becomes the deâАР
fault for future RIGHTARROW and LEFTARROW commands. While the text is scrolled, it acts as though the -S option (chop lines) were in efâАР
fect.

ESC-( or LEFTARROW
Scroll horizontally left N characters, default half the screen width (see the -# option). If a number N is specified, it becomes the deâАР
fault for future RIGHTARROW and LEFTARROW commands.

ESC-} or ^RIGHTARROW
Scroll horizontally right to show the end of the longest displayed line.

ESC-{ or ^LEFTARROW
Scroll horizontally left back to the first column.

r or ^R or ^L
Repaint the screen.

R Repaint the screen, discarding any buffered input. Useful if the file is changing while it is being viewed.

F Scroll forward, and keep trying to read when the end of file is reached. Normally this command would be used when already at the end of
the file. It is a way to monitor the tail of a file which is growing while it is being viewed. (The behavior is similar to the "tail -f"
command.)

ESC-F Like F, but as soon as a line is found which matches the last search pattern, the terminal bell is rung and forward scrolling stops.

g or < or ESC-<
Go to line N in the file, default 1 (beginning of file). (Warning: this may be slow if N is large.)

G or > or ESC->
Go to line N in the file, default the end of the file. (Warning: this may be slow if N is large, or if N is not specified and standard
input, rather than a file, is being read.)

ESC-G Same as G, except if no number N is specified and the input is standard input, goes to the last line which is currently buffered.

p or % Go to a position N percent into the file. N should be between 0 and 100, and may contain a decimal point.

P Go to the line containing byte offset N in the file.

{ If a left curly bracket appears in the top line displayed on the screen, the { command will go to the matching right curly bracket. The
matching right curly bracket is positioned on the bottom line of the screen. If there is more than one left curly bracket on the top
line, a number N may be used to specify the N-th bracket on the line.

} If a right curly bracket appears in the bottom line displayed on the screen, the } command will go to the matching left curly bracket.
The matching left curly bracket is positioned on the top line of the screen. If there is more than one right curly bracket on the top
line, a number N may be used to specify the N-th bracket on the line.

( Like {, but applies to parentheses rather than curly brackets.

) Like }, but applies to parentheses rather than curly brackets.

[ Like {, but applies to square brackets rather than curly brackets.

] Like }, but applies to square brackets rather than curly brackets.

ESC-^F Followed by two characters, acts like {, but uses the two characters as open and close brackets, respectively. For example, "ESC ^F < >"
could be used to go forward to the > which matches the < in the top displayed line.

ESC-^B Followed by two characters, acts like }, but uses the two characters as open and close brackets, respectively. For example, "ESC ^B < >"
could be used to go backward to the < which matches the > in the bottom displayed line.

m Followed by any lowercase or uppercase letter, marks the first displayed line with that letter. If the status column is enabled via the
-J option, the status column shows the marked line.

M Acts like m, except the last displayed line is marked rather than the first displayed line.

' (Single quote.) Followed by any lowercase or uppercase letter, returns to the position which was previously marked with that letter.
Followed by another single quote, returns to the position at which the last "large" movement command was executed. Followed by a ^ or $,
jumps to the beginning or end of the file respectively. Marks are preserved when a new file is examined, so the ' command can be used to
switch between input files.

^X^X Same as single quote.

ESC-m Followed by any lowercase or uppercase letter, clears the mark identified by that letter.

/pattern
Search forward in the file for the N-th line containing the pattern. N defaults to 1. The pattern is a regular expression, as recognized
by the regular expression library supplied by your system. The search starts at the first line displayed (but see the -a and -j options,
which change this).

Certain characters are special if entered at the beginning of the pattern; they modify the type of search rather than become part of the
pattern:

^N or !
Search for lines which do NOT match the pattern.

^E or *
Search multiple files. That is, if the search reaches the END of the current file without finding a match, the search continues in
the next file in the command line list.

^F or @
Begin the search at the first line of the FIRST file in the command line list, regardless of what is currently displayed on the
screen or the settings of the -a or -j options.

^K Highlight any text which matches the pattern on the current screen, but don't move to the first match (KEEP current position).

^R Don't interpret regular expression metacharacters; that is, do a simple textual comparison.

?pattern
Search backward in the file for the N-th line containing the pattern. The search starts at the last line displayed (but see the -a and -j
options, which change this).

Certain characters are special as in the / command:

^N or !
Search for lines which do NOT match the pattern.

^E or *
Search multiple files. That is, if the search reaches the beginning of the current file without finding a match, the search conâАР
tinues in the previous file in the command line list.

^F or @
Begin the search at the last line of the last file in the command line list, regardless of what is currently displayed on the
screen or the settings of the -a or -j options.

^K As in forward searches.

^R As in forward searches.

ESC-/pattern
Same as "/*".

ESC-?pattern
Same as "?*".

n Repeat previous search, for N-th line containing the last pattern. If the previous search was modified by ^N, the search is made for the
N-th line NOT containing the pattern. If the previous search was modified by ^E, the search continues in the next (or previous) file if
not satisfied in the current file. If the previous search was modified by ^R, the search is done without using regular expressions.
There is no effect if the previous search was modified by ^F or ^K.

N Repeat previous search, but in the reverse direction.

ESC-n Repeat previous search, but crossing file boundaries. The effect is as if the previous search were modified by *.

ESC-N Repeat previous search, but in the reverse direction and crossing file boundaries.

ESC-u Undo search highlighting. Turn off highlighting of strings matching the current search pattern. If highlighting is already off because
of a previous ESC-u command, turn highlighting back on. Any search command will also turn highlighting back on. (Highlighting can also
be disabled by toggling the -G option; in that case search commands do not turn highlighting back on.)

&pattern
Display only lines which match the pattern; lines which do not match the pattern are not displayed. If pattern is empty (if you type &
immediately followed by ENTER), any filtering is turned off, and all lines are displayed. While filtering is in effect, an ampersand is
displayed at the beginning of the prompt, as a reminder that some lines in the file may be hidden.

Certain characters are special as in the / command:

^N or !
Display only lines which do NOT match the pattern.

^R Don't interpret regular expression metacharacters; that is, do a simple textual comparison.

:e [filename]
Examine a new file. If the filename is missing, the "current" file (see the :n and :p commands below) from the list of files in the comâАР
mand line is re-examined. A percent sign (%) in the filename is replaced by the name of the current file. A pound sign (#) is replaced
by the name of the previously examined file. However, two consecutive percent signs are simply replaced with a single percent sign. This
allows you to enter a filename that contains a percent sign in the name. Similarly, two consecutive pound signs are replaced with a sinâАР
gle pound sign. The filename is inserted into the command line list of files so that it can be seen by subsequent :n and :p commands. If
the filename consists of several files, they are all inserted into the list of files and the first one is examined. If the filename conâАР
tains one or more spaces, the entire filename should be enclosed in double quotes (also see the -" option).

^X^V or E
Same as :e. Warning: some systems use ^V as a special literalization character. On such systems, you may not be able to use ^V.

:n Examine the next file (from the list of files given in the command line). If a number N is specified, the N-th next file is examined.

:p Examine the previous file in the command line list. If a number N is specified, the N-th previous file is examined.

:x Examine the first file in the command line list. If a number N is specified, the N-th file in the list is examined.

:d Remove the current file from the list of files.

t Go to the next tag, if there were more than one matches for the current tag. See the -t option for more details about tags.

T Go to the previous tag, if there were more than one matches for the current tag.

= or ^G or :f
Prints some information about the file being viewed, including its name and the line number and byte offset of the bottom line being disâАР
played. If possible, it also prints the length of the file, the number of lines in the file and the percent of the file above the last
displayed line.

- Followed by one of the command line option letters (see OPTIONS below), this will change the setting of that option and print a message
describing the new setting. If a ^P (CONTROL-P) is entered immediately after the dash, the setting of the option is changed but no mesâАР
sage is printed. If the option letter has a numeric value (such as -b or -h), or a string value (such as -P or -t), a new value may be
entered after the option letter. If no new value is entered, a message describing the current setting is printed and nothing is changed.

-- Like the - command, but takes a long option name (see OPTIONS below) rather than a single option letter. You must press ENTER or RETURN
after typing the option name. A ^P immediately after the second dash suppresses printing of a message describing the new setting, as in
the - command.

-+ Followed by one of the command line option letters this will reset the option to its default setting and print a message describing the
new setting. (The "-+X" command does the same thing as "-+X" on the command line.) This does not work for string-valued options.

--+ Like the -+ command, but takes a long option name rather than a single option letter.

-! Followed by one of the command line option letters, this will reset the option to the "opposite" of its default setting and print a mesâАР
sage describing the new setting. This does not work for numeric or string-valued options.

--! Like the -! command, but takes a long option name rather than a single option letter.

_ (Underscore.) Followed by one of the command line option letters, this will print a message describing the current setting of that opâАР
tion. The setting of the option is not changed.

__ (Double underscore.) Like the _ (underscore) command, but takes a long option name rather than a single option letter. You must press
ENTER or RETURN after typing the option name.

+cmd Causes the specified cmd to be executed each time a new file is examined. For example, +G causes less to initially display each file
starting at the end rather than the beginning.

V Prints the version number of less being run.

q or Q or :q or :Q or ZZ
Exits less.

The following four commands may or may not be valid, depending on your particular installation.

v Invokes an editor to edit the current file being viewed. The editor is taken from the environment variable VISUAL if defined, or EDITOR
if VISUAL is not defined, or defaults to "vi" if neither VISUAL nor EDITOR is defined. See also the discussion of LESSEDIT under the secâАР
tion on PROMPTS below.

! shell-command
Invokes a shell to run the shell-command given. A percent sign (%) in the command is replaced by the name of the current file. A pound
sign (#) is replaced by the name of the previously examined file. "!!" repeats the last shell command. "!" with no shell command simply
invokes a shell. On Unix systems, the shell is taken from the environment variable SHELL, or defaults to "sh". On MS-DOS and OS/2 sysâАР
tems, the shell is the normal command processor.

| <m> shell-command
<m> represents any mark letter. Pipes a section of the input file to the given shell command. The section of the file to be piped is beâАР
tween the position marked by the letter and the current screen. The entire current screen is included, regardless of whether the marked
position is before or after the current screen. <m> may also be ^ or $ to indicate beginning or end of file respectively. If <m> is . or
newline, the current screen is piped.

s filename
Save the input to a file. This only works if the input is a pipe, not an ordinary file.

OPTIONS

Command line options are described below. Most options may be changed while less is running, via the “-” command.

Most options may be given in one of two forms: either a dash followed by a single letter, or two dashes followed by a long option name. A long
option name may be abbreviated as long as the abbreviation is unambiguous. For example, --quit-at-eof may be abbreviated --quit, but not --qui,
since both --quit-at-eof and --quiet begin with --qui. Some long option names are in uppercase, such as --QUIT-AT-EOF, as distinct from --quit-
at-eof. Such option names need only have their first letter capitalized; the remainder of the name may be in either case. For example, --Quit-
at-eof is equivalent to --QUIT-AT-EOF.

Options are also taken from the environment variable "LESS". For example, to avoid typing "less -options ..." each time less is invoked, you
might tell csh:

setenv LESS "-options"

or if you use sh:

LESS="-options"; export LESS

On MS-DOS, you don't need the quotes, but you should replace any percent signs in the options string by double percent signs.

The environment variable is parsed before the command line, so command line options override the LESS environment variable. If an option appears
in the LESS variable, it can be reset to its default value on the command line by beginning the command line option with "-+".

Some options like -k or -D require a string to follow the option letter. The string for that option is considered to end when a dollar sign ($)
is found. For example, you can set two -D options on MS-DOS like this:

LESS="Dn9.1$Ds4.1"

If the --use-backslash option appears earlier in the options, then a dollar sign or backslash may be included literally in an option string by
preceding it with a backslash. If the --use-backslash option is not in effect, then backslashes are not treated specially, and there is no way
to include a dollar sign in the option string.

-? or --help
This option displays a summary of the commands accepted by less (the same as the h command). (Depending on how your shell interprets the
question mark, it may be necessary to quote the question mark, thus: "-\?".)

-a or --search-skip-screen
By default, forward searches start at the top of the displayed screen and backwards searches start at the bottom of the displayed screen
(except for repeated searches invoked by the n or N commands, which start after or before the "target" line respectively; see the -j opâАР
tion for more about the target line). The -a option causes forward searches to instead start at the bottom of the screen and backward
searches to start at the top of the screen, thus skipping all lines displayed on the screen.

-A or --SEARCH-SKIP-SCREEN
Causes all forward searches (not just non-repeated searches) to start just after the target line, and all backward searches to start just
before the target line. Thus, forward searches will skip part of the displayed screen (from the first line up to and including the target
line). Similarly backwards searches will skip the displayed screen from the last line up to and including the target line. This was the
default behavior in less versions prior to 441.

-bn or --buffers=n
Specifies the amount of buffer space less will use for each file, in units of kilobytes (1024 bytes). By default 64 K of buffer space is
used for each file (unless the file is a pipe; see the -B option). The -b option specifies instead that n kilobytes of buffer space
should be used for each file. If n is -1, buffer space is unlimited; that is, the entire file can be read into memory.

-B or --auto-buffers
By default, when data is read from a pipe, buffers are allocated automatically as needed. If a large amount of data is read from the
pipe, this can cause a large amount of memory to be allocated. The -B option disables this automatic allocation of buffers for pipes, so
that only 64 K (or the amount of space specified by the -b option) is used for the pipe. Warning: use of -B can result in erroneous disâАР
play, since only the most recently viewed part of the piped data is kept in memory; any earlier data is lost.

-c or --clear-screen
Causes full screen repaints to be painted from the top line down. By default, full screen repaints are done by scrolling from the bottom
of the screen.

-C or --CLEAR-SCREEN
Same as -c, for compatibility with older versions of less.

-d or --dumb
The -d option suppresses the error message normally displayed if the terminal is dumb; that is, lacks some important capability, such as
the ability to clear the screen or scroll backward. The -d option does not otherwise change the behavior of less on a dumb terminal.

-Dxcolor or --color=xcolor
[MS-DOS only] Sets the color of the text displayed. x is a single character which selects the type of text whose color is being set:
n=normal, s=standout, d=bold, u=underlined, k=blink. color is a pair of numbers separated by a period. The first number selects the
foreground color and the second selects the background color of the text. A single number N is the same as N.M, where M is the normal
background color. The color may start or end with u to use underline (with the normal color, if by itself), if the system supports it
(Windows only). x may also be a to toggle strict ANSI sequence rendering (SGR mode).

-e or --quit-at-eof
Causes less to automatically exit the second time it reaches end-of-file. By default, the only way to exit less is via the "q" command.

-E or --QUIT-AT-EOF
Causes less to automatically exit the first time it reaches end-of-file.

-f or --force
Forces non-regular files to be opened. (A non-regular file is a directory or a device special file.) Also suppresses the warning message
when a binary file is opened. By default, less will refuse to open non-regular files. Note that some operating systems will not allow
directories to be read, even if -f is set.

-F or --quit-if-one-screen
Causes less to automatically exit if the entire file can be displayed on the first screen.

-g or --hilite-search
Normally, less will highlight ALL strings which match the last search command. The -g option changes this behavior to highlight only the
particular string which was found by the last search command. This can cause less to run somewhat faster than the default.

-G or --HILITE-SEARCH
The -G option suppresses all highlighting of strings found by search commands.

-hn or --max-back-scroll=n
Specifies a maximum number of lines to scroll backward. If it is necessary to scroll backward more than n lines, the screen is repainted
in a forward direction instead. (If the terminal does not have the ability to scroll backward, -h0 is implied.)

-i or --ignore-case
Causes searches to ignore case; that is, uppercase and lowercase are considered identical. This option is ignored if any uppercase letâАР
ters appear in the search pattern; in other words, if a pattern contains uppercase letters, then that search does not ignore case.

-I or --IGNORE-CASE
Like -i, but searches ignore case even if the pattern contains uppercase letters.

-jn or --jump-target=n
Specifies a line on the screen where the "target" line is to be positioned. The target line is the line specified by any command to
search for a pattern, jump to a line number, jump to a file percentage or jump to a tag. The screen line may be specified by a number:
the top line on the screen is 1, the next is 2, and so on. The number may be negative to specify a line relative to the bottom of the
screen: the bottom line on the screen is -1, the second to the bottom is -2, and so on. Alternately, the screen line may be specified as
a fraction of the height of the screen, starting with a decimal point: .5 is in the middle of the screen, .3 is three tenths down from the
first line, and so on. If the line is specified as a fraction, the actual line number is recalculated if the terminal window is resized,
so that the target line remains at the specified fraction of the screen height. If any form of the -j option is used, repeated forward
searches (invoked with "n" or "N") begin at the line immediately after the target line, and repeated backward searches begin at the target
line, unless changed by -a or -A. For example, if "-j4" is used, the target line is the fourth line on the screen, so forward searches
begin at the fifth line on the screen. However nonrepeated searches (invoked with "/" or "?") always begin at the start or end of the
current screen respectively.

-J or --status-column
Displays a status column at the left edge of the screen. The status column shows the lines that matched the current search, and any lines
that are marked (via the m or M command). The status column is also used if the -w or -W option is in effect.

-kfilename or --lesskey-file=filename
Causes less to open and interpret the named file as a lesskey (1) file. Multiple -k options may be specified. If the LESSKEY or
LESSKEY_SYSTEM environment variable is set, or if a lesskey file is found in a standard place (see KEY BINDINGS), it is also used as a
lesskey file.

-K or --quit-on-intr
Causes less to exit immediately (with status 2) when an interrupt character (usually ^C) is typed. Normally, an interrupt character
causes less to stop whatever it is doing and return to its command prompt. Note that use of this option makes it impossible to return to
the command prompt from the "F" command.

-L or --no-lessopen
Ignore the LESSOPEN environment variable (see the INPUT PREPROCESSOR section below). This option can be set from within less, but it will
apply only to files opened subsequently, not to the file which is currently open.

-m or --long-prompt
Causes less to prompt verbosely (like more), with the percent into the file. By default, less prompts with a colon.

-M or --LONG-PROMPT
Causes less to prompt even more verbosely than more.

-n or --line-numbers
Suppresses line numbers. The default (to use line numbers) may cause less to run more slowly in some cases, especially with a very large
input file. Suppressing line numbers with the -n option will avoid this problem. Using line numbers means: the line number will be disâАР
played in the verbose prompt and in the = command, and the v command will pass the current line number to the editor (see also the discusâАР
sion of LESSEDIT in PROMPTS below).

-N or --LINE-NUMBERS
Causes a line number to be displayed at the beginning of each line in the display.

-ofilename or --log-file=filename
Causes less to copy its input to the named file as it is being viewed. This applies only when the input file is a pipe, not an ordinary
file. If the file already exists, less will ask for confirmation before overwriting it.

-Ofilename or --LOG-FILE=filename
The -O option is like -o, but it will overwrite an existing file without asking for confirmation.

If no log file has been specified, the -o and -O options can be used from within less to specify a log file. Without a file name, they
will simply report the name of the log file. The "s" command is equivalent to specifying -o from within less.

-ppattern or --pattern=pattern
The -p option on the command line is equivalent to specifying +/pattern; that is, it tells less to start at the first occurrence of patâАР
tern in the file.

-Pprompt or --prompt=prompt
Provides a way to tailor the three prompt styles to your own preference. This option would normally be put in the LESS environment variâАР
able, rather than being typed in with each less command. Such an option must either be the last option in the LESS variable, or be termiâАР
nated by a dollar sign.
-Ps followed by a string changes the default (short) prompt to that string.
-Pm changes the medium (-m) prompt.
-PM changes the long (-M) prompt.
-Ph changes the prompt for the help screen.
-P= changes the message printed by the = command.
-Pw changes the message printed while waiting for data (in the F command).

All prompt strings consist of a sequence of letters and special escape sequences. See the section on PROMPTS for more details.

-q or --quiet or --silent
Causes moderately "quiet" operation: the terminal bell is not rung if an attempt is made to scroll past the end of the file or before the
beginning of the file. If the terminal has a "visual bell", it is used instead. The bell will be rung on certain other errors, such as
typing an invalid character. The default is to ring the terminal bell in all such cases.

-Q or --QUIET or --SILENT
Causes totally "quiet" operation: the terminal bell is never rung. If the terminal has a "visual bell", it is used in all cases where the
terminal bell would have been rung.

-r or --raw-control-chars
Causes "raw" control characters to be displayed. The default is to display control characters using the caret notation; for example, a
control-A (octal 001) is displayed as "^A". Warning: when the -r option is used, less cannot keep track of the actual appearance of the
screen (since this depends on how the screen responds to each type of control character). Thus, various display problems may result, such
as long lines being split in the wrong place.

-R or --RAW-CONTROL-CHARS
Like -r, but only ANSI "color" escape sequences are output in "raw" form. Unlike -r, the screen appearance is maintained correctly in
most cases. ANSI "color" escape sequences are sequences of the form:

ESC [ ... m

where the "..." is zero or more color specification characters For the purpose of keeping track of screen appearance, ANSI color escape
sequences are assumed to not move the cursor. You can make less think that characters other than "m" can end ANSI color escape sequences
by setting the environment variable LESSANSIENDCHARS to the list of characters which can end a color escape sequence. And you can make
less think that characters other than the standard ones may appear between the ESC and the m by setting the environment variable LESSANâАР
SIMIDCHARS to the list of characters which can appear.

-s or --squeeze-blank-lines
Causes consecutive blank lines to be squeezed into a single blank line. This is useful when viewing nroff output.

-S or --chop-long-lines
Causes lines longer than the screen width to be chopped (truncated) rather than wrapped. That is, the portion of a long line that does
not fit in the screen width is not shown. The default is to wrap long lines; that is, display the remainder on the next line.

-ttag or --tag=tag
The -t option, followed immediately by a TAG, will edit the file containing that tag. For this to work, tag information must be availâАР
able; for example, there may be a file in the current directory called "tags", which was previously built by ctags (1) or an equivalent
command. If the environment variable LESSGLOBALTAGS is set, it is taken to be the name of a command compatible with global (1), and that
command is executed to find the tag. (See http://www.gnu.org/software/global/global.html). The -t option may also be specified from
within less (using the - command) as a way of examining a new file. The command ":t" is equivalent to specifying -t from within less.

-Ttagsfile or --tag-file=tagsfile
Specifies a tags file to be used instead of "tags".

-u or --underline-special
Causes backspaces and carriage returns to be treated as printable characters; that is, they are sent to the terminal when they appear in
the input.

-U or --UNDERLINE-SPECIAL
Causes backspaces, tabs, carriage returns and "formatting characters" (as defined by Unicode) to be treated as control characters; that
is, they are handled as specified by the -r option.

By default, if neither -u nor -U is given, backspaces which appear adjacent to an underscore character are treated specially: the underâАР
lined text is displayed using the terminal's hardware underlining capability. Also, backspaces which appear between two identical characâАР
ters are treated specially: the overstruck text is printed using the terminal's hardware boldface capability. Other backspaces are
deleted, along with the preceding character. Carriage returns immediately followed by a newline are deleted. Other carriage returns are
handled as specified by the -r option. Text which is overstruck or underlined can be searched for if neither -u nor -U is in effect.

-V or --version
Displays the version number of less.

-w or --hilite-unread
Temporarily highlights the first "new" line after a forward movement of a full page. The first "new" line is the line immediately followâАР
ing the line previously at the bottom of the screen. Also highlights the target line after a g or p command. The highlight is removed at
the next command which causes movement. The entire line is highlighted, unless the -J option is in effect, in which case only the status
column is highlighted.

-W or --HILITE-UNREAD
Like -w, but temporarily highlights the first new line after any forward movement command larger than one line.

-xn,... or --tabs=n,...
Sets tab stops. If only one n is specified, tab stops are set at multiples of n. If multiple values separated by commas are specified,
tab stops are set at those positions, and then continue with the same spacing as the last two. For example, -x9,17 will set tabs at posiâАР
tions 9, 17, 25, 33, etc. The default for n is 8.

-X or --no-init
Disables sending the termcap initialization and deinitialization strings to the terminal. This is sometimes desirable if the deinitialâАР
ization string does something unnecessary, like clearing the screen.

-yn or --max-forw-scroll=n
Specifies a maximum number of lines to scroll forward. If it is necessary to scroll forward more than n lines, the screen is repainted
instead. The -c or -C option may be used to repaint from the top of the screen if desired. By default, any forward movement causes
scrolling.

-zn or --window=n or -n
Changes the default scrolling window size to n lines. The default is one screenful. The z and w commands can also be used to change the
window size. The "z" may be omitted for compatibility with some versions of more. If the number n is negative, it indicates n lines less
than the current screen size. For example, if the screen is 24 lines, -z-4 sets the scrolling window to 20 lines. If the screen is reâАР
sized to 40 lines, the scrolling window automatically changes to 36 lines.

-"cc or --quotes=cc
Changes the filename quoting character. This may be necessary if you are trying to name a file which contains both spaces and quote charâАР
acters. Followed by a single character, this changes the quote character to that character. Filenames containing a space should then be
surrounded by that character rather than by double quotes. Followed by two characters, changes the open quote to the first character, and
the close quote to the second character. Filenames containing a space should then be preceded by the open quote character and followed by
the close quote character. Note that even after the quote characters are changed, this option remains -" (a dash followed by a double
quote).

-~ or --tilde
Normally lines after end of file are displayed as a single tilde (~). This option causes lines after end of file to be displayed as blank
lines.

-# or --shift
Specifies the default number of positions to scroll horizontally in the RIGHTARROW and LEFTARROW commands. If the number specified is
zero, it sets the default number of positions to one half of the screen width. Alternately, the number may be specified as a fraction of
the width of the screen, starting with a decimal point: .5 is half of the screen width, .3 is three tenths of the screen width, and so on.
If the number is specified as a fraction, the actual number of scroll positions is recalculated if the terminal window is resized, so that
the actual scroll remains at the specified fraction of the screen width.

--follow-name
Normally, if the input file is renamed while an F command is executing, less will continue to display the contents of the original file
despite its name change. If --follow-name is specified, during an F command less will periodically attempt to reopen the file by name.
If the reopen succeeds and the file is a different file from the original (which means that a new file has been created with the same name
as the original (now renamed) file), less will display the contents of that new file.

--mouse
Enables mouse input: scrolling the mouse wheel down moves forward in the file, scrolling the mouse wheel up moves backwards in the file,
and clicking the mouse sets the "#" mark to the line where the mouse is clicked. The number of lines to scroll when the wheel is moved
can be set by the --wheel-lines option. Mouse input works only on terminals which support X11 mouse reporting, and on the Windows version
of less.

--MOUSE
Like --mouse, except the direction scrolled on mouse wheel movement is reversed.

--no-keypad
Disables sending the keypad initialization and deinitialization strings to the terminal. This is sometimes useful if the keypad strings
make the numeric keypad behave in an undesirable manner.

--no-histdups
This option changes the behavior so that if a search string or file name is typed in, and the same string is already in the history list,
the existing copy is removed from the history list before the new one is added. Thus, a given string will appear only once in the history
list. Normally, a string may appear multiple times.

--rscroll
This option changes the character used to mark truncated lines. It may begin with a two-character attribute indicator like LESSBINFMT
does. If there is no attribute indicator, standout is used. If set to "-", truncated lines are not marked.

--save-marks
Save marks in the history file, so marks are retained across different invocations of less.

--use-backslash
This option changes the interpretations of options which follow this one. After the --use-backslash option, any backslash in an option
string is removed and the following character is taken literally. This allows a dollar sign to be included in option strings.

--wheel-lines=n
Set the number of lines to scroll when the mouse wheel is scrolled and the --mouse or --MOUSE option is in effect. The default is 1 line.

-- A command line argument of "--" marks the end of option arguments. Any arguments following this are interpreted as filenames. This can
be useful when viewing a file whose name begins with a "-" or "+".

+ If a command line option begins with +, the remainder of that option is taken to be an initial command to less. For example, +G tells
less to start at the end of the file rather than the beginning, and +/xyz tells it to start at the first occurrence of "xyz" in the file.
As a special case, +<number> acts like +<number>g; that is, it starts the display at the specified line number (however, see the caveat
under the "g" command above). If the option starts with ++, the initial command applies to every file being viewed, not just the first
one. The + command described previously may also be used to set (or change) an initial command for every file.

LINE EDITING

       When entering command line at the bottom of the screen (for example, a filename for the :e command, or the pattern for a search command), certain
       keys can be used to manipulate the command line.  Most commands have an alternate form in [ brackets ] which can be used if a key does not  exist
       on  a  particular keyboard.  (Note that the forms beginning with ESC do not work in some MS-DOS and Windows systems because ESC is the line erase
       character.)  Any of these special keys may be entered literally by preceding it with the "literal" character, either ^V or ^A.  A  backslash  itâАР
       self may also be entered literally by entering two backslashes.

       LEFTARROW [ ESC-h ]
              Move the cursor one space to the left.

       RIGHTARROW [ ESC-l ]
              Move the cursor one space to the right.

       ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
              (That is, CONTROL and LEFTARROW simultaneously.)  Move the cursor one word to the left.

       ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
              (That is, CONTROL and RIGHTARROW simultaneously.)  Move the cursor one word to the right.

       HOME [ ESC-0 ]
              Move the cursor to the beginning of the line.

       END [ ESC-$ ]
              Move the cursor to the end of the line.

       BACKSPACE
              Delete the character to the left of the cursor, or cancel the command if the command line is empty.

       DELETE or [ ESC-x ]
              Delete the character under the cursor.

       ^BACKSPACE [ ESC-BACKSPACE ]
              (That is, CONTROL and BACKSPACE simultaneously.)  Delete the word to the left of the cursor.

       ^DELETE [ ESC-X or ESC-DELETE ]
              (That is, CONTROL and DELETE simultaneously.)  Delete the word under the cursor.

       UPARROW [ ESC-k ]
              Retrieve  the previous command line.  If you first enter some text and then press UPARROW, it will retrieve the previous command which beâАР
              gins with that text.

       DOWNARROW [ ESC-j ]
              Retrieve the next command line.  If you first enter some text and then press DOWNARROW, it will retrieve the  next  command  which  begins
              with that text.

       TAB    Complete  the  partial filename to the left of the cursor.  If it matches more than one filename, the first match is entered into the comâАР
              mand line.  Repeated TABs will cycle thru the other matching filenames.  If the completed filename is a directory, a "/"  is  appended  to
              the  filename.  (On MS-DOS systems, a "\" is appended.)  The environment variable LESSSEPARATOR can be used to specify a different characâАР
              ter to append to a directory name.

       BACKTAB [ ESC-TAB ]
              Like, TAB, but cycles in the reverse direction thru the matching filenames.

       ^L     Complete the partial filename to the left of the cursor.  If it matches more than one filename, all matches are entered into  the  command
              line (if they fit).

       ^U (Unix and OS/2) or ESC (MS-DOS)
              Delete  the entire command line, or cancel the command if the command line is empty.  If you have changed your line-kill character in Unix
              to something other than ^U, that character is used instead of ^U.

       ^G     Delete the entire command line and return to the main prompt.

KEY BINDINGS

You may define your own less commands by using the program lesskey (1) to create a lesskey file. This file specifies a set of command keys and
an action associated with each key. You may also use lesskey to change the line-editing keys (see LINE EDITING), and to set environment variâАР
ables. If the environment variable LESSKEY is set, less uses that as the name of the lesskey file. Otherwise, less looks in a standard place
for the lesskey file: On Unix systems, less looks for a lesskey file called "$HOME/.less". On MS-DOS and Windows systems, less looks for a
lesskey file called "$HOME/less", and if it is not found there, then looks for a lesskey file called "less" in any directory specified in the
PATH environment variable. On OS/2 systems, less looks for a lesskey file called "$HOME/less.ini", and if it is not found, then looks for a
lesskey file called "less.ini" in any directory specified in the INIT environment variable, and if it not found there, then looks for a lesskey
file called "less.ini" in any directory specified in the PATH environment variable. See the lesskey manual page for more details.

A system-wide lesskey file may also be set up to provide key bindings. If a key is defined in both a local lesskey file and in the system-wide
file, key bindings in the local file take precedence over those in the system-wide file. If the environment variable LESSKEY_SYSTEM is set, less
uses that as the name of the system-wide lesskey file. Otherwise, less looks in a standard place for the system-wide lesskey file: On Unix sysâАР
tems, the system-wide lesskey file is /usr/local/etc/sysless. (However, if less was built with a different sysconf directory than /usr/loâАР
cal/etc, that directory is where the sysless file is found.) On MS-DOS and Windows systems, the system-wide lesskey file is c:\_sysless. On
OS/2 systems, the system-wide lesskey file is c:\sysless.ini.

INPUT PREPROCESSOR

You may define an "input preprocessor" for less. Before less opens a file, it first gives your input preprocessor a chance to modify the way the
contents of the file are displayed. An input preprocessor is simply an executable program (or shell script), which writes the contents of the
file to a different file, called the replacement file. The contents of the replacement file are then displayed in place of the contents of the
original file. However, it will appear to the user as if the original file is opened; that is, less will display the original filename as the
name of the current file.

An input preprocessor receives one command line argument, the original filename, as entered by the user. It should create the replacement file,
and when finished, print the name of the replacement file to its standard output. If the input preprocessor does not output a replacement fileâАР
name, less uses the original file, as normal. The input preprocessor is not called when viewing standard input. To set up an input preprocesâАР
sor, set the LESSOPEN environment variable to a command line which will invoke your input preprocessor. This command line should include one ocâАР
currence of the string "%s", which will be replaced by the filename when the input preprocessor command is invoked.

When less closes a file opened in such a way, it will call another program, called the input postprocessor, which may perform any desired clean-
up action (such as deleting the replacement file created by LESSOPEN). This program receives two command line arguments, the original filename
as entered by the user, and the name of the replacement file. To set up an input postprocessor, set the LESSCLOSE environment variable to a comâАР
mand line which will invoke your input postprocessor. It may include two occurrences of the string "%s"; the first is replaced with the original
name of the file and the second with the name of the replacement file, which was output by LESSOPEN.

For example, on many Unix systems, these two scripts will allow you to keep files in compressed format, but still let less view them directly:

lessopen.sh:
#! /bin/sh
case "$1" in
*.Z) TEMPFILE=$(mktemp)
uncompress -c $1 >$TEMPFILE 2>/dev/null
if [ -s $TEMPFILE ]; then
echo $TEMPFILE
else
rm -f $TEMPFILE
fi
;;
esac

lessclose.sh:
#! /bin/sh
rm $2

To use these scripts, put them both where they can be executed and set LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More comâАР
plex LESSOPEN and LESSCLOSE scripts may be written to accept other types of compressed files, and so on.

It is also possible to set up an input preprocessor to pipe the file data directly to less, rather than putting the data into a replacement file.
This avoids the need to decompress the entire file before starting to view it. An input preprocessor that works this way is called an input
pipe. An input pipe, instead of writing the name of a replacement file on its standard output, writes the entire contents of the replacement
file on its standard output. If the input pipe does not write any characters on its standard output, then there is no replacement file and less
uses the original file, as normal. To use an input pipe, make the first character in the LESSOPEN environment variable a vertical bar (|) to
signify that the input preprocessor is an input pipe. As with non-pipe input preprocessors, the command string must contain one occurrence of
%s, which is replaced with the filename of the input file.

For example, on many Unix systems, this script will work like the previous example scripts:

lesspipe.sh:
#! /bin/sh
case "$1" in
*.Z) uncompress -c $1 2>/dev/null
;;
*) exit 1
;;
esac
exit $?

To use this script, put it where it can be executed and set LESSOPEN="|lesspipe.sh %s".

Note that a preprocessor cannot output an empty file, since that is interpreted as meaning there is no replacement, and the original file is
used. To avoid this, if LESSOPEN starts with two vertical bars, the exit status of the script becomes meaningful. If the exit status is zero,
the output is considered to be replacement text, even if it is empty. If the exit status is nonzero, any output is ignored and the original file
is used. For compatibility with previous versions of less, if LESSOPEN starts with only one vertical bar, the exit status of the preprocessor is
ignored.

When an input pipe is used, a LESSCLOSE postprocessor can be used, but it is usually not necessary since there is no replacement file to clean
up. In this case, the replacement file name passed to the LESSCLOSE postprocessor is "-".

For compatibility with previous versions of less, the input preprocessor or pipe is not used if less is viewing standard input. However, if the
first character of LESSOPEN is a dash (-), the input preprocessor is used on standard input as well as other files. In this case, the dash is
not considered to be part of the preprocessor command. If standard input is being viewed, the input preprocessor is passed a file name consistâАР
ing of a single dash. Similarly, if the first two characters of LESSOPEN are vertical bar and dash (|-) or two vertical bars and a dash (||-),
the input pipe is used on standard input as well as other files. Again, in this case the dash is not considered to be part of the input pipe
command.

NATIONAL CHARACTER SETS

There are three types of characters in the input file:

normal characters
can be displayed directly to the screen.

control characters
should not be displayed directly, but are expected to be found in ordinary text files (such as backspace and tab).

binary characters
should not be displayed directly and are not expected to be found in text files.

A "character set" is simply a description of which characters are to be considered normal, control, and binary. The LESSCHARSET environment
variable may be used to select a character set. Possible values for LESSCHARSET are:

ascii BS, TAB, NL, CR, and formfeed are control characters, all chars with values between 32 and 126 are normal, and all others are binary.

iso8859
Selects an ISO 8859 character set. This is the same as ASCII, except characters between 160 and 255 are treated as normal characters.

latin1 Same as iso8859.

latin9 Same as iso8859.

dos Selects a character set appropriate for MS-DOS.

ebcdic Selects an EBCDIC character set.

IBM-1047
Selects an EBCDIC character set used by OS/390 Unix Services. This is the EBCDIC analogue of latin1. You get similar results by setting
either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your environment.

koi8-r Selects a Russian character set.

next Selects a character set appropriate for NeXT computers.

utf-8 Selects the UTF-8 encoding of the ISO 10646 character set. UTF-8 is special in that it supports multi-byte characters in the input file.
It is the only character set that supports multi-byte characters.

windows
Selects a character set appropriate for Microsoft Windows (cp 1251).

In rare cases, it may be desired to tailor less to use a character set other than the ones definable by LESSCHARSET. In this case, the environâАР
ment variable LESSCHARDEF can be used to define a character set. It should be set to a string where each character in the string represents one
character in the character set. The character "." is used for a normal character, "c" for control, and "b" for binary. A decimal number may be
used for repetition. For example, "bccc4b." would mean character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are binary, and 8 is normal.
All characters after the last are taken to be the same as the last, so characters 9 through 255 would be normal. (This is an example, and does
not necessarily represent any real character set.)

This table shows the value of LESSCHARDEF which is equivalent to each of the possible values for LESSCHARSET:

ascii 8bcccbcc18b95.b
dos 8bcccbcc12bc5b95.b.
ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
191.b
iso8859 8bcccbcc18b95.33b.
koi8-r 8bcccbcc18b95.b128.
latin1 8bcccbcc18b95.33b.
next 8bcccbcc18b95.bb125.bb

If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or LANG
environment variables, then the default character set is utf-8.

If that string is not found, but your system supports the setlocale interface, less will use setlocale to determine the character set. setlocale
is controlled by setting the LANG or LC_CTYPE environment variables.

Finally, if the setlocale interface is also not available, the default character set is latin1.

Control and binary characters are displayed in standout (reverse video). Each such character is displayed in caret notation if possible (e.g. ^A
for control-A). Caret notation is used only if inverting the 0100 bit results in a normal printable character. Otherwise, the character is disâАР
played as a hex number in angle brackets. This format can be changed by setting the LESSBINFMT environment variable. LESSBINFMT may begin with
a "" and one character to select the display attribute: "k" is blinking, "d" is bold, "u" is underlined, "s" is standout, and "n" is norâАР
mal. If LESSBINFMT does not begin with a "", normal attribute is assumed. The remainder of LESSBINFMT is a string which may include one
printf-style escape sequence (a % followed by x, X, o, d, etc.). For example, if LESSBINFMT is "u[%x]", binary characters are displayed in unâАР
derlined hexadecimal surrounded by brackets. The default if no LESSBINFMT is specified is "*s<%02X>". Warning: the result of expanding the
character via LESSBINFMT must be less than 31 characters.

When the character set is utf-8, the LESSUTFBINFMT environment variable acts similarly to LESSBINFMT but it applies to Unicode code points that
were successfully decoded but are unsuitable for display (e.g., unassigned code points). Its default value is "<U+%04lX>". Note that LESSUTFâАР
BINFMT and LESSBINFMT share their display attribute setting ("*x") so specifying one will affect both; LESSUTFBINFMT is read after LESSBINFMT so
its setting, if any, will have priority. Problematic octets in a UTF-8 file (octets of a truncated sequence, octets of a complete but non-shortâАР
est form sequence, illegal octets, and stray trailing octets) are displayed individually using LESSBINFMT so as to facilitate diagnostic of how
the UTF-8 file is ill-formed.

PROMPTS

The -P option allows you to tailor the prompt to your preference. The string given to the -P option replaces the specified prompt string. CerâАР
tain characters in the string are interpreted specially. The prompt mechanism is rather complicated to provide flexibility, but the ordinary
user need not understand the details of constructing personalized prompt strings.

A percent sign followed by a single character is expanded according to what the following character is:

%bX Replaced by the byte offset into the current input file. The b is followed by a single character (shown as X above) which specifies the
line whose byte offset is to be used. If the character is a "t", the byte offset of the top line in the display is used, an "m" means use
the middle line, a "b" means use the bottom line, a "B" means use the line just after the bottom line, and a "j" means use the "target"
line, as specified by the -j option.

%B Replaced by the size of the current input file.

%c Replaced by the column number of the text appearing in the first column of the screen.

%dX Replaced by the page number of a line in the input file. The line to be used is determined by the X, as with the %b option.

%D Replaced by the number of pages in the input file, or equivalently, the page number of the last line in the input file.

%E Replaced by the name of the editor (from the VISUAL environment variable, or the EDITOR environment variable if VISUAL is not defined).
See the discussion of the LESSEDIT feature below.

%f Replaced by the name of the current input file.

%F Replaced by the last component of the name of the current input file.

%g Replaced by the shell-escaped name of the current input file. This is useful when the expanded string will be used in a shell command,
such as in LESSEDIT.

%i Replaced by the index of the current file in the list of input files.

%lX Replaced by the line number of a line in the input file. The line to be used is determined by the X, as with the %b option.

%L Replaced by the line number of the last line in the input file.

%m Replaced by the total number of input files.

%pX Replaced by the percent into the current input file, based on byte offsets. The line used is determined by the X as with the %b option.

%PX Replaced by the percent into the current input file, based on line numbers. The line used is determined by the X as with the %b option.

%s Same as %B.

%t Causes any trailing spaces to be removed. Usually used at the end of the string, but may appear anywhere.

%T Normally expands to the word "file". However if viewing files via a tags list using the -t option, it expands to the word "tag".

%x Replaced by the name of the next input file in the list.

If any item is unknown (for example, the file size if input is a pipe), a question mark is printed instead.

The format of the prompt string can be changed depending on certain conditions. A question mark followed by a single character acts like an
"IF": depending on the following character, a condition is evaluated. If the condition is true, any characters following the question mark and
condition character, up to a period, are included in the prompt. If the condition is false, such characters are not included. A colon appearing
between the question mark and the period can be used to establish an "ELSE": any characters between the colon and the period are included in the
string if and only if the IF condition is false. Condition characters (which follow a question mark) may be:

?a True if any characters have been included in the prompt so far.

?bX True if the byte offset of the specified line is known.

?B True if the size of current input file is known.

?c True if the text is horizontally shifted (%c is not zero).

?dX True if the page number of the specified line is known.

?e True if at end-of-file.

?f True if there is an input filename (that is, if input is not a pipe).

?lX True if the line number of the specified line is known.

?L True if the line number of the last line in the file is known.

?m True if there is more than one input file.

?n True if this is the first prompt in a new input file.

?pX True if the percent into the current input file, based on byte offsets, of the specified line is known.

?PX True if the percent into the current input file, based on line numbers, of the specified line is known.

?s Same as "?B".

?x True if there is a next input file (that is, if the current input file is not the last one).

Any characters other than the special ones (question mark, colon, period, percent, and backslash) become literally part of the prompt. Any of
the special characters may be included in the prompt literally by preceding it with a backslash.

Some examples:

?f%f:Standard input.

This prompt prints the filename, if known; otherwise the string "Standard input".

?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...

This prompt would print the filename, if known. The filename is followed by the line number, if known, otherwise the percent if known, otherwise
the byte offset if known. Otherwise, a dash is printed. Notice how each question mark has a matching period, and how the % after the %pt is inâАР
cluded literally by escaping it with a backslash.

?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x..%t";

This prints the filename if this is the first prompt in a file, followed by the "file N of N" message if there is more than one input file.
Then, if we are at end-of-file, the string "(END)" is printed followed by the name of the next file, if there is one. Finally, any trailing spaâАР
ces are truncated. This is the default prompt. For reference, here are the defaults for the other two prompts (-m and -M respectively). Each
is broken into two lines here for readability only.

?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x.:
?pB%pB\%:byte %bB?s/%s...%t

?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :
byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t

And here is the default message produced by the = command:

?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .
byte %bB?s/%s. ?e(END) :?pB%pB\%..%t

The prompt expansion features are also used for another purpose: if an environment variable LESSEDIT is defined, it is used as the command to be
executed when the v command is invoked. The LESSEDIT string is expanded in the same way as the prompt strings. The default value for LESSEDIT
is:

%E ?lm+%lm. %g

Note that this expands to the editor name, followed by a + and the line number, followed by the shell-escaped file name. If your editor does not
accept the "+linenumber" syntax, or has other differences in invocation syntax, the LESSEDIT variable can be changed to modify this default.

SECURITY

When the environment variable LESSSECURE is set to 1, less runs in a “secure” mode. This means these features are disabled:

! the shell command

| the pipe command

:e the examine command.

v the editing command

s -o log files

-k use of lesskey files

-t use of tags files

metacharacters in filenames, such as *

filename completion (TAB, ^L)

Less can also be compiled to be permanently in “secure” mode.

COMPATIBILITY WITH MORE

       If the environment variable LESS_IS_MORE is set to 1, or if the program is invoked via a file link named "more", less behaves (mostly) in conforâАР
       mance with the POSIX "more" command specification.  In this mode, less behaves differently in these ways:

       The -e option works differently.  If the -e option is not set, less behaves as if the -e option were set.  If the -e option is set, less  behaves
       as if the -E option were set.

       The  -m option works differently.  If the -m option is not set, the medium prompt is used, and it is prefixed with the string "--More--".  If the
       -m option is set, the short prompt is used.

       The -n option acts like the -z option.  The normal behavior of the -n option is unavailable in this mode.

       The parameter to the -p option is taken to be a less command rather than a search pattern.

       The LESS environment variable is ignored, and the MORE environment variable is used in its place.

ENVIRONMENT VARIABLES

Environment variables may be specified either in the system environment as usual, or in a lesskey (1) file. If environment variables are defined
in more than one place, variables defined in a local lesskey file take precedence over variables defined in the system environment, which take
precedence over variables defined in the system-wide lesskey file.

COLUMNS
Sets the number of columns on the screen. Takes precedence over the number of columns specified by the TERM variable. (But if you have a
windowing system which supports TIOCGWINSZ or WIOCGETD, the window system's idea of the screen size takes precedence over the LINES and
COLUMNS environment variables.)

EDITOR The name of the editor (used for the v command).

HOME Name of the user's home directory (used to find a lesskey file on Unix and OS/2 systems).

HOMEDRIVE, HOMEPATH
Concatenation of the HOMEDRIVE and HOMEPATH environment variables is the name of the user's home directory if the HOME variable is not set
(only in the Windows version).

INIT Name of the user's init directory (used to find a lesskey file on OS/2 systems).

LANG Language for determining the character set.

LC_CTYPE
Language for determining the character set.

LESS Options which are passed to less automatically.

LESSANSIENDCHARS
Characters which may end an ANSI color escape sequence (default "m").

LESSANSIMIDCHARS
Characters which may appear between the ESC character and the end character in an ANSI color escape sequence (default
"0123456789:;[?!"'#%()*+ ".

LESSBINFMT
Format for displaying non-printable, non-control characters.

LESSCHARDEF
Defines a character set.

LESSCHARSET
Selects a predefined character set.

LESSCLOSE
Command line to invoke the (optional) input-postprocessor.

LESSECHO
Name of the lessecho program (default "lessecho"). The lessecho program is needed to expand metacharacters, such as * and ?, in filenames
on Unix systems.

LESSEDIT
Editor prototype string (used for the v command). See discussion under PROMPTS.

LESSGLOBALTAGS
Name of the command used by the -t option to find global tags. Normally should be set to "global" if your system has the global (1) comâАР
mand. If not set, global tags are not used.

LESSHISTFILE
Name of the history file used to remember search commands and shell commands between invocations of less. If set to "-" or "/dev/null", a
history file is not used. The default is "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on DOS and Windows systems, or
"$HOME/lesshst.ini" or "$INIT/lesshst.ini" on OS/2 systems.

LESSHISTSIZE
The maximum number of commands to save in the history file. The default is 100.

LESSKEY
Name of the default lesskey(1) file.

LESSKEY_SYSTEM
Name of the default system-wide lesskey(1) file.

LESSMETACHARS
List of characters which are considered "metacharacters" by the shell.

LESSMETAESCAPE
Prefix which less will add before each metacharacter in a command sent to the shell. If LESSMETAESCAPE is an empty string, commands conâАР
taining metacharacters will not be passed to the shell.

LESSOPEN
Command line to invoke the (optional) input-preprocessor.

LESSSECURE
Runs less in "secure" mode. See discussion under SECURITY.

LESSSEPARATOR
String to be appended to a directory name in filename completion.

LESSUTFBINFMT
Format for displaying non-printable Unicode code points.

LESS_IS_MORE
Emulate the more (1) command.

LINES Sets the number of lines on the screen. Takes precedence over the number of lines specified by the TERM variable. (But if you have a
windowing system which supports TIOCGWINSZ or WIOCGETD, the window system's idea of the screen size takes precedence over the LINES and
COLUMNS environment variables.)

MORE Options which are passed to less automatically when running in more compatible mode.

PATH User's search path (used to find a lesskey file on MS-DOS and OS/2 systems).

SHELL The shell used to execute the ! command, as well as to expand filenames.

TERM The type of terminal on which less is being run.

VISUAL The name of the editor (used for the v command).

SEE ALSO

lesskey(1)

COPYRIGHT

       less  is  part  of  the GNU project and is free software.  You can redistribute it and/or modify it under the terms of either (1) the GNU General
       Public License as published by the Free Software Foundation; or (2) the Less License.  See the file README in the less distribution for more  deâАР
       tails  regarding  redistribution.  You should have received a copy of the GNU General Public License along with the source for less; see the file
       COPYING.  If not, write to the Free Software Foundation, 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.  You should also have  received
       a copy of the Less License; see the file LICENSE.

       less is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
       FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

AUTHOR

       Mark Nudelman
       Report bugs at https://github.com/gwsw/less/issues.
       For more information, see the less homepage at
       http://www.greenwoodsoftware.com/less.

                                                                Version 551: 11 Jun 2019                                                         LESS(1)

Linux manpage

manpage mv

MV(1) User Commands MV(1)

NAME

mv – move (rename) files

SYNOPSIS

       mv [OPTION]... [-T] SOURCE DEST
       mv [OPTION]... SOURCE... DIRECTORY
       mv [OPTION]... -t DIRECTORY SOURCE...

DESCRIPTION

Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.

Mandatory arguments to long options are mandatory for short options too.

       --backup[=CONTROL]
              make a backup of each existing destination file

       -b     like --backup but does not accept an argument

       -f, --force
              do not prompt before overwriting

       -i, --interactive
              prompt before overwrite

       -n, --no-clobber
              do not overwrite an existing file

       If you specify more than one of -i, -f, -n, only the final one takes effect.

       --strip-trailing-slashes
              remove any trailing slashes from each SOURCE argument

       -S, --suffix=SUFFIX
              override the usual backup suffix

       -t, --target-directory=DIRECTORY
              move all SOURCE arguments into DIRECTORY

       -T, --no-target-directory
              treat DEST as a normal file

       -u, --update
              move only when the SOURCE file is newer than the destination file or when the destination file is missing

       -v, --verbose
              explain what is being done

       -Z, --context
              set SELinux security context of destination file to default type

       --help display this help and exit

       --version
              output version information and exit

       The  backup  suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.  The version control method may be selected via the --backup option
       or through the VERSION_CONTROL environment variable.  Here are the values:

       none, off
              never make backups (even if --backup is given)

       numbered, t
              make numbered backups

       existing, nil
              numbered if numbered backups exist, simple otherwise

       simple, never
              always make simple backups

AUTHOR

Written by Mike Parker, David MacKenzie, and Jim Meyering.

REPORTING BUGS

       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
       Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT

       Copyright Â© 2020 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

rename(2)

       Full documentation <https://www.gnu.org/software/coreutils/mv>
       or available locally via: info '(coreutils) mv invocation'

GNU coreutils 8.32                                                   September 2020                                                                MV(1)

Linux manpage

manpage netstat

NETSTAT(8) Linux System Administrator’s Manual NETSTAT(8)

NAME

netstat – Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships

SYNOPSIS

       netstat  [address_family_options]  [--tcp|-t]  [--udp|-u]  [--udplite|-U]  [--sctp|-S]  [--raw|-w]  [--l2cap|-2]  [--rfcomm|-f]  [--listening|-l]
       [--all|-a] [--numeric|-n] [--numeric-hosts] [--numeric-ports] [--numeric-users] [--symbolic|-N] [--extend|-e[--extend|-e]] [--timers|-o]  [--proâАР
       gram|-p] [--verbose|-v] [--continuous|-c] [--wide|-W]

       netstat {--route|-r} [address_family_options] [--extend|-e[--extend|-e]] [--verbose|-v] [--numeric|-n] [--numeric-hosts] [--numeric-ports] [--nuâАР
       meric-users] [--continuous|-c]

       netstat {--interfaces|-i} [--all|-a] [--extend|-e[--extend|-e]] [--verbose|-v] [--program|-p] [--numeric|-n] [--numeric-hosts]  [--numeric-ports]
       [--numeric-users] [--continuous|-c]

       netstat {--groups|-g} [--numeric|-n] [--numeric-hosts] [--numeric-ports] [--numeric-users] [--continuous|-c]

       netstat {--masquerade|-M} [--extend|-e] [--numeric|-n] [--numeric-hosts] [--numeric-ports] [--numeric-users] [--continuous|-c]

       netstat {--statistics|-s} [--tcp|-t] [--udp|-u] [--udplite|-U] [--sctp|-S] [--raw|-w]

       netstat {--version|-V}

       netstat {--help|-h}

       address_family_options:

       [-4|--inet]  [-6|--inet6]  [--protocol={inet,inet6,unix,ipx,ax25,netrom,ddp,bluetooth, ... } ] [--unix|-x] [--inet|--ip|--tcpip] [--ax25] [--x25]
       [--rose] [--ash] [--bluetooth] [--ipx] [--netrom] [--ddp|--appletalk] [--econet|--ec]

NOTES

       This program is mostly obsolete.  Replacement for netstat is ss.  Replacement for netstat -r is ip route.  Replacement for netstat -i  is  ip  -s
       link.  Replacement for netstat -g is ip maddr.

DESCRIPTION

       Netstat  prints  information  about the Linux networking subsystem.  The type of information printed is controlled by the first argument, as folâАР
       lows:

(none)

       By default, netstat displays a list of open sockets.  If you don't specify any address families, then the active sockets of  all  configured  adâАР
       dress families will be printed.

–route, -r

Display the kernel routing tables. See the description in route(8) for details. netstat -r and route -e produce the same output.

–groups, -g

Display multicast group membership information for IPv4 and IPv6.

–interfaces, -i

Display a table of all network interfaces.

–masquerade, -M

Display a list of masqueraded connections.

–statistics, -s

Display summary statistics for each protocol.

OPTIONS

–verbose, -v

Tell the user what is going on by being verbose. Especially print some useful information about unconfigured address families.

–wide, -W

Do not truncate IP addresses by using output as wide as needed. This is optional for now to not break existing scripts.

–numeric, -n

Show numerical addresses instead of trying to determine symbolic host, port or user names.

–numeric-hosts

shows numerical host addresses but does not affect the resolution of port or user names.

–numeric-ports

shows numerical port numbers but does not affect the resolution of host or user names.

–numeric-users

shows numerical user IDs but does not affect the resolution of host or port names.

–protocol=family, -A

       Specifies  the address families (perhaps better described as low level protocols) for which connections are to be shown.  family is a comma (',')
       separated list of address family keywords like inet, inet6, unix, ipx, ax25, netrom, econet, ddp, and bluetooth.  This has the same effect as usâАР
       ing the --inet|-4, --inet6|-6, --unix|-x, --ipx, --ax25, --netrom, --ddp, and --bluetooth options.

       The address family inet (Iv4) includes raw, udp, udplite and tcp protocol sockets.

       The address family bluetooth (Iv4) includes l2cap and rfcomm protocol sockets.

-c, –continuous

This will cause netstat to print the selected information every second continuously.

-e, –extend

Display additional information. Use this option twice for maximum detail.

-o, –timers

Include information related to networking timers.

-p, –program

Show the PID and name of the program to which each socket belongs.

-l, –listening

Show only listening sockets. (These are omitted by default.)

-a, –all

Show both listening and non-listening sockets. With the –interfaces option, show interfaces that are not up

-F

Print routing information from the FIB. (This is the default.)

-C

Print routing information from the route cache.

OUTPUT

Active Internet connections (TCP, UDP, UDPLite, raw) Proto

The protocol (tcp, udp, udpl, raw) used by the socket.

Recv-Q

       Established: The count of bytes not copied by the user program connected to this socket.  Listening: Since Kernel 2.6.18 this column contains the
       current syn backlog.

Send-Q

       Established: The count of bytes not acknowledged by the remote host.  Listening: Since Kernel 2.6.18 this column contains the maximum size of the
       syn backlog.

Local Address

       Address  and  port  number  of the local end of the socket.  Unless the --numeric (-n) option is specified, the socket address is resolved to its
       canonical host name (FQDN), and the port number is translated into the corresponding service name.

Foreign Address

Address and port number of the remote end of the socket. Analogous to “Local Address”.

State

       The state of the socket. Since there are no states in raw mode and usually no states used in UDP and UDPLite, this column may be left blank. NorâАР
       mally this can be one of several values:

       ESTABLISHED
              The socket has an established connection.

       SYN_SENT
              The socket is actively attempting to establish a connection.

       SYN_RECV
              A connection request has been received from the network.

       FIN_WAIT1
              The socket is closed, and the connection is shutting down.

       FIN_WAIT2
              Connection is closed, and the socket is waiting for a shutdown from the remote end.

       TIME_WAIT
              The socket is waiting after close to handle packets still in the network.

       CLOSE  The socket is not being used.

       CLOSE_WAIT
              The remote end has shut down, waiting for the socket to close.

       LAST_ACK
              The remote end has shut down, and the socket is closed. Waiting for acknowledgement.

       LISTEN The  socket is listening for incoming connections.  Such sockets are not included in the output unless you specify the --listening (-l) or
              --all (-a) option.

       CLOSING
              Both sockets are shut down but we still don't have all our data sent.

       UNKNOWN
              The state of the socket is unknown.

User

The username or the user id (UID) of the owner of the socket.

PID/Program name

       Slash-separated pair of the process id (PID) and process name of the process that owns the socket.  --program causes this column to be  included.
       You  will  also need superuser privileges to see this information on sockets you don't own.  This identification information is not yet available
       for IPX sockets.

Timer

(this needs to be written)

Active UNIX domain Sockets
Proto

The protocol (usually unix) used by the socket.

RefCnt

The reference count (i.e. attached processes via this socket).

Flags

       The flags displayed is SO_ACCEPTON (displayed as ACC), SO_WAITDATA (W) or SO_NOSPACE (N).  SO_ACCECPTON is used on unconnected sockets  if  their
       corresponding processes are waiting for a connect request. The other flags are not of normal interest.

Type

There are several types of socket access:

       SOCK_DGRAM
              The socket is used in Datagram (connectionless) mode.

       SOCK_STREAM
              This is a stream (connection) socket.

       SOCK_RAW
              The socket is used as a raw socket.

       SOCK_RDM
              This one serves reliably-delivered messages.

       SOCK_SEQPACKET
              This is a sequential packet socket.

       SOCK_PACKET
              Raw interface access socket.

       UNKNOWN
              Who ever knows what the future will bring us - just fill in here :-)

State

This field will contain one of the following Keywords:

FREE The socket is not allocated

       LISTENING
              The  socket  is  listening  for a connection request.  Such sockets are only included in the output if you specify the --listening (-l) or
              --all (-a) option.

       CONNECTING
              The socket is about to establish a connection.

       CONNECTED
              The socket is connected.

       DISCONNECTING
              The socket is disconnecting.

       (empty)
              The socket is not connected to another one.

       UNKNOWN
              This state should never happen.

PID/Program name

       Process ID (PID) and process name of the process that has the socket open.  More info available in Active Internet  connections  section  written
       above.

Path

This is the path name as which the corresponding processes attached to the socket.

Active IPX sockets

(this needs to be done by somebody who knows it)

Active NET/ROM sockets

(this needs to be done by somebody who knows it)

Active AX.25 sockets

(this needs to be done by somebody who knows it)

FILES

/etc/services — The services translation file

/proc — Mount point for the proc filesystem, which gives access to kernel status information via the following files.

/proc/net/dev — device information

/proc/net/raw — raw socket information

/proc/net/tcp — TCP socket information

/proc/net/udp — UDP socket information

/proc/net/udplite — UDPLite socket information

/proc/net/igmp — IGMP multicast information

/proc/net/unix — Unix domain socket information

/proc/net/ipx — IPX socket information

/proc/net/ax25 — AX25 socket information

/proc/net/appletalk — DDP (appletalk) socket information

/proc/net/nr — NET/ROM socket information

/proc/net/route — IP routing information

/proc/net/ax25_route — AX25 routing information

/proc/net/ipx_route — IPX routing information

/proc/net/nr_nodes — NET/ROM nodelist

/proc/net/nr_neigh — NET/ROM neighbours

/proc/net/ip_masquerade — masqueraded connections

/sys/kernel/debug/bluetooth/l2cap — Bluetooth L2CAP information

/sys/kernel/debug/bluetooth/rfcomm — Bluetooth serial connections

/proc/net/snmp — statistics

SEE ALSO

route(8), ifconfig(8), iptables(8), proc(5) ss(8) ip(8)

BUGS

Occasionally strange information may appear if a socket changes as it is viewed. This is unlikely to occur.

AUTHORS

       The  netstat user interface was written by Fred Baumgarten <dc6iq@insu1.etec.uni-karlsruhe.de>, the man page basically by Matt Welsh <mdw@tc.corâАР
       nell.edu>. It was updated by Alan Cox <Alan.Cox@linux.org>, updated again by Tuan Hoang <tqhoang@bigfoot.com>. The man page and the  command  inâАР
       cluded  in  the  net-tools  package  is  totally  rewritten  by  Bernd  Eckenfels  <ecki@linux.de>.   UDPLite  options  were added by Brian Micek
       <bmicek@gmail.com>

net-tools                                                              2014-10-07                                                             NETSTAT(8)

Tags interface statistics, masquerade connections, multicast memberships, netstat, Print network connections, routing tables

Linux manpage

manpage ps

PS(1) User Commands PS(1)

NAME

ps – report a snapshot of the current processes.

SYNOPSIS

ps [options]

DESCRIPTION

ps displays information about a selection of the active processes. If you want a repetitive update of the selection and the displayed
information, use top instead.

This version of ps accepts several kinds of options:

1 UNIX options, which may be grouped and must be preceded by a dash.
2 BSD options, which may be grouped and must not be used with a dash.
3 GNU long options, which are preceded by two dashes.

Options of different types may be freely mixed, but conflicts can appear. There are some synonymous options, which are functionally identical,
due to the many standards and ps implementations that this ps is compatible with.

Note that ps -aux is distinct from ps aux. The POSIX and UNIX standards require that ps -aux print all processes owned by a user named x, as
well as printing all processes that would be selected by the -a option. If the user named x does not exist, this ps may interpret the command as
ps aux instead and print a warning. This behavior is intended to aid in transitioning old scripts and habits. It is fragile, subject to change,
and thus should not be relied upon.

By default, ps selects all processes with the same effective user ID (euid=EUID) as the current user and associated with the same terminal as the
invoker. It displays the process ID (pid=PID), the terminal associated with the process (tname=TTY), the cumulated CPU time in [DD-]hh:mm:ss
format (time=TIME), and the executable name (ucmd=CMD). Output is unsorted by default.

The use of BSD-style options will add process state (stat=STAT) to the default display and show the command args (args=COMMAND) instead of the
executable name. You can override this with the PS_FORMAT environment variable. The use of BSD-style options will also change the process
selection to include processes on other terminals (TTYs) that are owned by you; alternately, this may be described as setting the selection to be
the set of all processes filtered to exclude processes owned by other users or not on a terminal. These effects are not considered when options
are described as being "identical" below, so -M will be considered identical to Z and so on.

Except as described below, process selection options are additive. The default selection is discarded, and then the selected processes are added
to the set of processes to be displayed. A process will thus be shown if it meets any of the given selection criteria.

EXAMPLES

       To see every process on the system using standard syntax:
          ps -e
          ps -ef
          ps -eF
          ps -ely

       To see every process on the system using BSD syntax:
          ps ax
          ps axu

       To print a process tree:
          ps -ejH
          ps axjf

       To get info about threads:
          ps -eLf
          ps axms

       To get security info:
          ps -eo euser,ruser,suser,fuser,f,comm,label
          ps axZ
          ps -eM

       To see every process running as root (real & effective ID) in user format:
          ps -U root -u root u

       To see every process with a user-defined format:
          ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm
          ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm
          ps -Ao pid,tt,user,fname,tmout,f,wchan

       Print only the process IDs of syslogd:
          ps -C syslogd -o pid=

       Print only the name of PID 42:
          ps -q 42 -o comm=

SIMPLE PROCESS SELECTION

a Lift the BSD-style "only yourself" restriction, which is imposed upon the set of all processes when some BSD-style (without "-") options
are used or when the ps personality setting is BSD-like. The set of processes selected in this manner is in addition to the set of
processes selected by other means. An alternate description is that this option causes ps to list all processes with a terminal (tty), or
to list all processes when used together with the x option.

-A Select all processes. Identical to -e.

-a Select all processes except both session leaders (see getsid(2)) and processes not associated with a terminal.

-d Select all processes except session leaders.

--deselect
Select all processes except those that fulfill the specified conditions (negates the selection). Identical to -N.

-e Select all processes. Identical to -A.

g Really all, even session leaders. This flag is obsolete and may be discontinued in a future release. It is normally implied by the a
flag, and is only useful when operating in the sunos4 personality.

-N Select all processes except those that fulfill the specified conditions (negates the selection). Identical to --deselect.

T Select all processes associated with this terminal. Identical to the t option without any argument.

r Restrict the selection to only running processes.

x Lift the BSD-style "must have a tty" restriction, which is imposed upon the set of all processes when some BSD-style (without "-") options
are used or when the ps personality setting is BSD-like. The set of processes selected in this manner is in addition to the set of
processes selected by other means. An alternate description is that this option causes ps to list all processes owned by you (same EUID
as ps), or to list all processes when used together with the a option.

PROCESS SELECTION BY LIST

These options accept a single argument in the form of a blank-separated or comma-separated list. They can be used multiple times. For example:
ps -p "1 2" -p 3,4

-123 Identical to --pid 123.

123 Identical to --pid 123.

-C cmdlist
Select by command name. This selects the processes whose executable name is given in cmdlist. NOTE: The command name is not the same as
the command line. Previous versions of procps and the kernel truncated this command name to 15 characters. This limitation is no longer
present in both. If you depended on matching only 15 characters, you may no longer get a match.

-G grplist
Select by real group ID (RGID) or name. This selects the processes whose real group name or ID is in the grplist list. The real group ID
identifies the group of the user who created the process, see getgid(2).

-g grplist
Select by session OR by effective group name. Selection by session is specified by many standards, but selection by effective group is
the logical behavior that several other operating systems use. This ps will select by session when the list is completely numeric (as
sessions are). Group ID numbers will work only when some group names are also specified. See the -s and --group options.

--Group grplist
Select by real group ID (RGID) or name. Identical to -G.

--group grplist
Select by effective group ID (EGID) or name. This selects the processes whose effective group name or ID is in grplist. The effective
group ID describes the group whose file access permissions are used by the process (see getegid(2)). The -g option is often an
alternative to --group.

p pidlist
Select by process ID. Identical to -p and --pid.

-p pidlist
Select by PID. This selects the processes whose process ID numbers appear in pidlist. Identical to p and --pid.

--pid pidlist
Select by process ID. Identical to -p and p.

--ppid pidlist
Select by parent process ID. This selects the processes with a parent process ID in pidlist. That is, it selects processes that are
children of those listed in pidlist.

q pidlist
Select by process ID (quick mode). Identical to -q and --quick-pid.

-q pidlist
Select by PID (quick mode). This selects the processes whose process ID numbers appear in pidlist. With this option ps reads the
necessary info only for the pids listed in the pidlist and doesn't apply additional filtering rules. The order of pids is unsorted and
preserved. No additional selection options, sorting and forest type listings are allowed in this mode. Identical to q and --quick-pid.

--quick-pid pidlist
Select by process ID (quick mode). Identical to -q and q.

-s sesslist
Select by session ID. This selects the processes with a session ID specified in sesslist.

--sid sesslist
Select by session ID. Identical to -s.

t ttylist
Select by tty. Nearly identical to -t and --tty, but can also be used with an empty ttylist to indicate the terminal associated with ps.
Using the T option is considered cleaner than using t with an empty ttylist.

-t ttylist
Select by tty. This selects the processes associated with the terminals given in ttylist. Terminals (ttys, or screens for text output)
can be specified in several forms: /dev/ttyS1, ttyS1, S1. A plain "-" may be used to select processes not attached to any terminal.

--tty ttylist
Select by terminal. Identical to -t and t.

U userlist
Select by effective user ID (EUID) or name. This selects the processes whose effective user name or ID is in userlist. The effective
user ID describes the user whose file access permissions are used by the process (see geteuid(2)). Identical to -u and --user.

-U userlist
Select by real user ID (RUID) or name. It selects the processes whose real user name or ID is in the userlist list. The real user ID
identifies the user who created the process, see getuid(2).

-u userlist
Select by effective user ID (EUID) or name. This selects the processes whose effective user name or ID is in userlist.

The effective user ID describes the user whose file access permissions are used by the process (see geteuid(2)). Identical to U and
--user.

--User userlist
Select by real user ID (RUID) or name. Identical to -U.

--user userlist
Select by effective user ID (EUID) or name. Identical to -u and U.

OUTPUT FORMAT CONTROL

These options are used to choose the information displayed by ps. The output may differ by personality.

-c Show different scheduler information for the -l option.

--context
Display security context format (for SELinux).

-f Do full-format listing. This option can be combined with many other UNIX-style options to add additional columns. It also causes the
command arguments to be printed. When used with -L, the NLWP (number of threads) and LWP (thread ID) columns will be added. See the c
option, the format keyword args, and the format keyword comm.

-F Extra full format. See the -f option, which -F implies.

--format format
user-defined format. Identical to -o and o.

j BSD job control format.

-j Jobs format.

l Display BSD long format.

-l Long format. The -y option is often useful with this.

-M Add a column of security data. Identical to Z (for SELinux).

O format
is preloaded o (overloaded). The BSD O option can act like -O (user-defined output format with some common fields predefined) or can be
used to specify sort order. Heuristics are used to determine the behavior of this option. To ensure that the desired behavior is
obtained (sorting or formatting), specify the option in some other way (e.g. with -O or --sort). When used as a formatting option, it is
identical to -O, with the BSD personality.

-O format
Like -o, but preloaded with some default columns. Identical to -o pid,format,state,tname,time,command or -o pid,format,tname,time,cmd,
see -o below.

o format
Specify user-defined format. Identical to -o and --format.

-o format
User-defined format. format is a single argument in the form of a blank-separated or comma-separated list, which offers a way to specify
individual output columns. The recognized keywords are described in the STANDARD FORMAT SPECIFIERS section below. Headers may be renamed
(ps -o pid,ruser=RealUser -o comm=Command) as desired. If all column headers are empty (ps -o pid= -o comm=) then the header line will
not be output. Column width will increase as needed for wide headers; this may be used to widen up columns such as WCHAN (ps -o pid,
wchan=WIDE-WCHAN-COLUMN -o comm). Explicit width control (ps opid,wchan:42,cmd) is offered too. The behavior of ps -o pid=X,comm=Y
varies with personality; output may be one column named "X,comm=Y" or two columns named "X" and "Y". Use multiple -o options when in
doubt. Use the PS_FORMAT environment variable to specify a default as desired; DefSysV and DefBSD are macros that may be used to choose
the default UNIX or BSD columns.

s Display signal format.

u Display user-oriented format.

v Display virtual memory format.

X Register format.

-y Do not show flags; show rss in place of addr. This option can only be used with -l.

Z Add a column of security data. Identical to -M (for SELinux).

OUTPUT MODIFIERS

c Show the true command name. This is derived from the name of the executable file, rather than from the argv value. Command arguments and
any modifications to them are thus not shown. This option effectively turns the args format keyword into the comm format keyword; it is
useful with the -f format option and with the various BSD-style format options, which all normally display the command arguments. See the
-f option, the format keyword args, and the format keyword comm.

--cols n
Set screen width.

--columns n
Set screen width.

--cumulative
Include some dead child process data (as a sum with the parent).

e Show the environment after the command.

f ASCII art process hierarchy (forest).

--forest
ASCII art process tree.

h No header. (or, one header per screen in the BSD personality). The h option is problematic. Standard BSD ps uses this option to print a
header on each page of output, but older Linux ps uses this option to totally disable the header. This version of ps follows the Linux
usage of not printing the header unless the BSD personality has been selected, in which case it prints a header on each page of output.
Regardless of the current personality, you can use the long options --headers and --no-headers to enable printing headers each page or
disable headers entirely, respectively.

-H Show process hierarchy (forest).

--headers
Repeat header lines, one per page of output.

k spec Specify sorting order. Sorting syntax is [+|-]key[,[+|-]key[,...]]. Choose a multi-letter key from the STANDARD FORMAT SPECIFIERS
section. The "+" is optional since default direction is increasing numerical or lexicographic order. Identical to --sort.

Examples:
ps jaxkuid,-ppid,+pid
ps axk comm o comm,args
ps kstart_time -ef

--lines n
Set screen height.

n Numeric output for WCHAN and USER (including all types of UID and GID).

--no-headers
Print no header line at all. --no-heading is an alias for this option.

O order
Sorting order (overloaded). The BSD O option can act like -O (user-defined output format with some common fields predefined) or can be
used to specify sort order. Heuristics are used to determine the behavior of this option. To ensure that the desired behavior is
obtained (sorting or formatting), specify the option in some other way (e.g. with -O or --sort).

For sorting, obsolete BSD O option syntax is O[+|-]k1[,[+|-]k2[,...]]. It orders the processes listing according to the multilevel sort
specified by the sequence of one-letter short keys k1,k2, ... described in the OBSOLETE SORT KEYS section below. The "+" is currently
optional, merely re-iterating the default direction on a key, but may help to distinguish an O sort from an O format. The "-" reverses
direction only on the key it precedes.

--rows n
Set screen height.

S Sum up some information, such as CPU usage, from dead child processes into their parent. This is useful for examining a system where a
parent process repeatedly forks off short-lived children to do work.

--sort spec
Specify sorting order. Sorting syntax is [+|-]key[,[+|-]key[,...]]. Choose a multi-letter key from the STANDARD FORMAT SPECIFIERS
section. The "+" is optional since default direction is increasing numerical or lexicographic order. Identical to k. For example: ps
jax --sort=uid,-ppid,+pid

w Wide output. Use this option twice for unlimited width.

-w Wide output. Use this option twice for unlimited width.

--width n
Set screen width.

THREAD DISPLAY

H Show threads as if they were processes.

-L Show threads, possibly with LWP and NLWP columns.

m Show threads after processes.

-m Show threads after processes.

-T Show threads, possibly with SPID column.

OTHER INFORMATION

       --help section
              Print a help message.  The section argument can be one of simple, list, output, threads, misc, or all.  The argument can be shortened to
              one of the underlined letters as in: s|l|o|t|m|a.

       --info Print debugging info.

       L      List all format specifiers.

       V      Print the procps-ng version.

       -V     Print the procps-ng version.

       --version
              Print the procps-ng version.

NOTES

       This ps works by reading the virtual files in /proc.  This ps does not need to be setuid kmem or have any privileges to run.  Do not give this ps
       any special permissions.

       CPU usage is currently expressed as the percentage of time spent running during the entire lifetime of a process.  This is not ideal, and it does
       not conform to the standards that ps otherwise conforms to.  CPU usage is unlikely to add up to exactly 100%.

       The SIZE and RSS fields don't count some parts of a process including the page tables, kernel stack, struct thread_info, and struct task_struct.
       This is usually at least 20 KiB of memory that is always resident.  SIZE is the virtual size of the process (code+data+stack).

       Processes marked <defunct> are dead processes (so-called "zombies") that remain because their parent has not destroyed them properly.  These
       processes will be destroyed by init(8) if the parent process exits.

       If the length of the username is greater than the length of the display column, the username will be truncated.  See the -o and -O formatting
       options to customize length.

       Commands options such as ps -aux are not recommended as it is a confusion of two different standards.  According to the POSIX and UNIX standards,
       the above command asks to display all processes with a TTY (generally the commands users are running) plus all processes owned by a user named x.
       If that user doesn't exist, then ps will assume you really meant ps aux.

PROCESS FLAGS

The sum of these values is displayed in the “F” column, which is provided by the flags output specifier:

               1    forked but didn't exec
               4    used super-user privileges

PROCESS STATE CODES

       Here are the different values that the s, stat and state output specifiers (header "STAT" or "S") will display to describe the state of a
       process:

               D    uninterruptible sleep (usually IO)
               I    Idle kernel thread
               R    running or runnable (on run queue)
               S    interruptible sleep (waiting for an event to complete)
               T    stopped by job control signal
               t    stopped by debugger during the tracing
               W    paging (not valid since the 2.6.xx kernel)
               X    dead (should never be seen)
               Z    defunct ("zombie") process, terminated but not reaped by its parent

       For BSD formats and when the stat keyword is used, additional characters may be displayed:

               <    high-priority (not nice to other users)
               N    low-priority (nice to other users)
               L    has pages locked into memory (for real-time and custom IO)
               s    is a session leader
               l    is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
               +    is in the foreground process group

OBSOLETE SORT KEYS

       These keys are used by the BSD O option (when it is used for sorting).  The GNU --sort option doesn't use these keys, but the specifiers
       described below in the STANDARD FORMAT SPECIFIERS section.  Note that the values used in sorting are the internal values ps uses and not the
       "cooked" values used in some of the output format fields (e.g.  sorting on tty will sort into device number, not according to the terminal name
       displayed).  Pipe ps output into the sort(1) command if you want to sort the cooked values.

       KEY   LONG         DESCRIPTION
       c     cmd          simple name of executable
       C     pcpu         cpu utilization
       f     flags        flags as in long format F field
       g     pgrp         process group ID
       G     tpgid        controlling tty process group ID
       j     cutime       cumulative user time
       J     cstime       cumulative system time
       k     utime        user time
       m     min_flt      number of minor page faults
       M     maj_flt      number of major page faults
       n     cmin_flt     cumulative minor page faults
       N     cmaj_flt     cumulative major page faults
       o     session      session ID
       p     pid          process ID
       P     ppid         parent process ID
       r     rss          resident set size
       R     resident     resident pages
       s     size         memory size in kilobytes
       S     share        amount of shared pages
       t     tty          the device number of the controlling tty
       T     start_time   time process was started
       U     uid          user ID number
       u     user         user name
       v     vsize        total VM size in KiB
       y     priority     kernel scheduling priority

AIX FORMAT DESCRIPTORS

       This ps supports AIX format descriptors, which work somewhat like the formatting codes of printf(1) and printf(3).  For example, the normal
       default output can be produced with this: ps -eo "%p %y %x %c".  The NORMAL codes are described in the next section.

       CODE   NORMAL   HEADER
       %C     pcpu     %CPU
       %G     group    GROUP
       %P     ppid     PPID
       %U     user     USER
       %a     args     COMMAND
       %c     comm     COMMAND
       %g     rgroup   RGROUP
       %n     nice     NI
       %p     pid      PID
       %r     pgid     PGID
       %t     etime    ELAPSED
       %u     ruser    RUSER
       %x     time     TIME
       %y     tty      TTY
       %z     vsz      VSZ

STANDARD FORMAT SPECIFIERS

Here are the different keywords that may be used to control the output format (e.g., with option -o) or to sort the selected processes with the
GNU-style --sort option.

For example: ps -eo pid,user,args --sort user

This version of ps tries to recognize most of the keywords used in other implementations of ps.

The following user-defined format specifiers may contain spaces: args, cmd, comm, command, fname, ucmd, ucomm, lstart, bsdstart, start.

Some keywords may not be available for sorting.

CODE HEADER DESCRIPTION

%cpu %CPU cpu utilization of the process in "##.#" format. Currently, it is the CPU time used divided by the time the process has
been running (cputime/realtime ratio), expressed as a percentage. It will not add up to 100% unless you are lucky. (alias
pcpu).

%mem %MEM ratio of the process's resident set size to the physical memory on the machine, expressed as a percentage. (alias pmem).

args COMMAND command with all its arguments as a string. Modifications to the arguments may be shown. The output in this column may
contain spaces. A process marked <defunct> is partly dead, waiting to be fully destroyed by its parent. Sometimes the
process args will be unavailable; when this happens, ps will instead print the executable name in brackets. (alias cmd,
command). See also the comm format keyword, the -f option, and the c option.
When specified last, this column will extend to the edge of the display. If ps can not determine display width, as when
output is redirected (piped) into a file or another command, the output width is undefined (it may be 80, unlimited,
determined by the TERM variable, and so on). The COLUMNS environment variable or --cols option may be used to exactly
determine the width in this case. The w or -w option may be also be used to adjust width.

blocked BLOCKED mask of the blocked signals, see signal(7). According to the width of the field, a 32 or 64-bit mask in hexadecimal format
is displayed. (alias sig_block, sigmask).

bsdstart START time the command started. If the process was started less than 24 hours ago, the output format is " HH:MM", else it is "
Mmm:SS" (where Mmm is the three letters of the month). See also lstart, start, start_time, and stime.

bsdtime TIME accumulated cpu time, user + system. The display format is usually "MMM:SS", but can be shifted to the right if the
process used more than 999 minutes of cpu time.

c C processor utilization. Currently, this is the integer value of the percent usage over the lifetime of the process. (see
%cpu).

caught CAUGHT mask of the caught signals, see signal(7). According to the width of the field, a 32 or 64 bits mask in hexadecimal format
is displayed. (alias sig_catch, sigcatch).

cgname CGNAME display name of control groups to which the process belongs.

cgroup CGROUP display control groups to which the process belongs.

class CLS scheduling class of the process. (alias policy, cls). Field's possible values are:

- not reported
TS SCHED_OTHER
FF SCHED_FIFO
RR SCHED_RR
B SCHED_BATCH
ISO SCHED_ISO
IDL SCHED_IDLE
DLN SCHED_DEADLINE
? unknown value

cls CLS scheduling class of the process. (alias policy, cls). Field's possible values are:

- not reported
TS SCHED_OTHER
FF SCHED_FIFO
RR SCHED_RR
B SCHED_BATCH
ISO SCHED_ISO
IDL SCHED_IDLE
DLN SCHED_DEADLINE
? unknown value

cmd CMD see args. (alias args, command).

comm COMMAND command name (only the executable name). Modifications to the command name will not be shown. A process marked <defunct>
is partly dead, waiting to be fully destroyed by its parent. The output in this column may contain spaces. (alias ucmd,
ucomm). See also the args format keyword, the -f option, and the c option.
When specified last, this column will extend to the edge of the display. If ps can not determine display width, as when
output is redirected (piped) into a file or another command, the output width is undefined (it may be 80, unlimited,
determined by the TERM variable, and so on). The COLUMNS environment variable or --cols option may be used to exactly
determine the width in this case. The w or -w option may be also be used to adjust width.

command COMMAND See args. (alias args, command).

cp CP per-mill (tenths of a percent) CPU usage. (see %cpu).

cputime TIME cumulative CPU time, "[DD-]hh:mm:ss" format. (alias time).

cputimes TIME cumulative CPU time in seconds (alias times).

drs DRS data resident set size, the amount of physical memory devoted to other than executable code.

egid EGID effective group ID number of the process as a decimal integer. (alias gid).

egroup EGROUP effective group ID of the process. This will be the textual group ID, if it can be obtained and the field width permits,
or a decimal representation otherwise. (alias group).

eip EIP instruction pointer.

esp ESP stack pointer.

etime ELAPSED elapsed time since the process was started, in the form [[DD-]hh:]mm:ss.

etimes ELAPSED elapsed time since the process was started, in seconds.

euid EUID effective user ID (alias uid).

euser EUSER effective user name. This will be the textual user ID, if it can be obtained and the field width permits, or a decimal
representation otherwise. The n option can be used to force the decimal representation. (alias uname, user).

exe EXE path to the executable. Useful if path cannot be printed via cmd, comm or args format options.

f F flags associated with the process, see the PROCESS FLAGS section. (alias flag, flags).

fgid FGID filesystem access group ID. (alias fsgid).

fgroup FGROUP filesystem access group ID. This will be the textual group ID, if it can be obtained and the field width permits, or a
decimal representation otherwise. (alias fsgroup).

flag F see f. (alias f, flags).

flags F see f. (alias f, flag).

fname COMMAND first 8 bytes of the base name of the process's executable file. The output in this column may contain spaces.

fuid FUID filesystem access user ID. (alias fsuid).

fuser FUSER filesystem access user ID. This will be the textual user ID, if it can be obtained and the field width permits, or a
decimal representation otherwise.

gid GID see egid. (alias egid).

group GROUP see egroup. (alias egroup).

ignored IGNORED mask of the ignored signals, see signal(7). According to the width of the field, a 32 or 64 bits mask in hexadecimal
format is displayed. (alias sig_ignore, sigignore).

ipcns IPCNS Unique inode number describing the namespace the process belongs to. See namespaces(7).

label LABEL security label, most commonly used for SELinux context data. This is for the Mandatory Access Control ("MAC") found on
high-security systems.

lstart STARTED time the command started. See also bsdstart, start, start_time, and stime.

lsession SESSION displays the login session identifier of a process, if systemd support has been included.

luid LUID displays Login ID associated with a process.

lwp LWP light weight process (thread) ID of the dispatchable entity (alias spid, tid). See tid for additional information.

lxc LXC The name of the lxc container within which a task is running. If a process is not running inside a container, a dash ('-')
will be shown.

machine MACHINE displays the machine name for processes assigned to VM or container, if systemd support has been included.

maj_flt MAJFLT The number of major page faults that have occurred with this process.

min_flt MINFLT The number of minor page faults that have occurred with this process.

mntns MNTNS Unique inode number describing the namespace the process belongs to. See namespaces(7).

netns NETNS Unique inode number describing the namespace the process belongs to. See namespaces(7).

ni NI nice value. This ranges from 19 (nicest) to -20 (not nice to others), see nice(1). (alias nice).

nice NI see ni.(alias ni).

nlwp NLWP number of lwps (threads) in the process. (alias thcount).

numa NUMA The node associated with the most recently used processor. A -1 means that NUMA information is unavailable.

nwchan WCHAN address of the kernel function where the process is sleeping (use wchan if you want the kernel function name). Running
tasks will display a dash ('-') in this column.

ouid OWNER displays the Unix user identifier of the owner of the session of a process, if systemd support has been included.

pcpu %CPU see %cpu. (alias %cpu).

pending PENDING mask of the pending signals. See signal(7). Signals pending on the process are distinct from signals pending on
individual threads. Use the m option or the -m option to see both. According to the width of the field, a 32 or 64 bits
mask in hexadecimal format is displayed. (alias sig).

pgid PGID process group ID or, equivalently, the process ID of the process group leader. (alias pgrp).

pgrp PGRP see pgid. (alias pgid).

pid PID a number representing the process ID (alias tgid).

pidns PIDNS Unique inode number describing the namespace the process belongs to. See namespaces(7).

pmem %MEM see %mem. (alias %mem).

policy POL scheduling class of the process. (alias class, cls). Possible values are:

- not reported
TS SCHED_OTHER
FF SCHED_FIFO
RR SCHED_RR
B SCHED_BATCH
ISO SCHED_ISO
IDL SCHED_IDLE
DLN SCHED_DEADLINE
? unknown value

ppid PPID parent process ID.

pri PRI priority of the process. Higher number means lower priority.

psr PSR processor that process is currently assigned to.

rgid RGID real group ID.

rgroup RGROUP real group name. This will be the textual group ID, if it can be obtained and the field width permits, or a decimal
representation otherwise.

rss RSS resident set size, the non-swapped physical memory that a task has used (in kilobytes). (alias rssize, rsz).

rssize RSS see rss. (alias rss, rsz).

rsz RSZ see rss. (alias rss, rssize).

rtprio RTPRIO realtime priority.

ruid RUID real user ID.

ruser RUSER real user ID. This will be the textual user ID, if it can be obtained and the field width permits, or a decimal
representation otherwise.

s S minimal state display (one character). See section PROCESS STATE CODES for the different values. See also stat if you
want additional information displayed. (alias state).

sched SCH scheduling policy of the process. The policies SCHED_OTHER (SCHED_NORMAL), SCHED_FIFO, SCHED_RR, SCHED_BATCH, SCHED_ISO,
SCHED_IDLE and SCHED_DEADLINE are respectively displayed as 0, 1, 2, 3, 4, 5 and 6.

seat SEAT displays the identifier associated with all hardware devices assigned to a specific workplace, if systemd support has been
included.

sess SESS session ID or, equivalently, the process ID of the session leader. (alias session, sid).

sgi_p P processor that the process is currently executing on. Displays "*" if the process is not currently running or runnable.

sgid SGID saved group ID. (alias svgid).

sgroup SGROUP saved group name. This will be the textual group ID, if it can be obtained and the field width permits, or a decimal
representation otherwise.

sid SID see sess. (alias sess, session).

sig PENDING see pending. (alias pending, sig_pend).

sigcatch CAUGHT see caught. (alias caught, sig_catch).

sigignore IGNORED see ignored. (alias ignored, sig_ignore).

sigmask BLOCKED see blocked. (alias blocked, sig_block).

size SIZE approximate amount of swap space that would be required if the process were to dirty all writable pages and then be swapped
out. This number is very rough!

slice SLICE displays the slice unit which a process belongs to, if systemd support has been included.

spid SPID see lwp. (alias lwp, tid).

stackp STACKP address of the bottom (start) of stack for the process.

start STARTED time the command started. If the process was started less than 24 hours ago, the output format is "HH:MM:SS", else it is
" Mmm dd" (where Mmm is a three-letter month name). See also lstart, bsdstart, start_time, and stime.

start_time START starting time or date of the process. Only the year will be displayed if the process was not started the same year ps was
invoked, or "MmmDD" if it was not started the same day, or "HH:MM" otherwise. See also bsdstart, start, lstart, and stime.

stat STAT multi-character process state. See section PROCESS STATE CODES for the different values meaning. See also s and state if
you just want the first character displayed.

state S see s. (alias s).

stime STIME see start_time. (alias start_time).

suid SUID saved user ID. (alias svuid).

supgid SUPGID group ids of supplementary groups, if any. See getgroups(2).

supgrp SUPGRP group names of supplementary groups, if any. See getgroups(2).

suser SUSER saved user name. This will be the textual user ID, if it can be obtained and the field width permits, or a decimal
representation otherwise. (alias svuser).

svgid SVGID see sgid. (alias sgid).

svuid SVUID see suid. (alias suid).

sz SZ size in physical pages of the core image of the process. This includes text, data, and stack space. Device mappings are
currently excluded; this is subject to change. See vsz and rss.

tgid TGID a number representing the thread group to which a task belongs (alias pid). It is the process ID of the thread group
leader.

thcount THCNT see nlwp. (alias nlwp). number of kernel threads owned by the process.

tid TID the unique number representing a dispatchable entity (alias lwp, spid). This value may also appear as: a process ID (pid);
a process group ID (pgrp); a session ID for the session leader (sid); a thread group ID for the thread group leader (tgid);
and a tty process group ID for the process group leader (tpgid).

time TIME cumulative CPU time, "[DD-]HH:MM:SS" format. (alias cputime).

times TIME cumulative CPU time in seconds (alias cputimes).

tname TTY controlling tty (terminal). (alias tt, tty).

tpgid TPGID ID of the foreground process group on the tty (terminal) that the process is connected to, or -1 if the process is not
connected to a tty.

trs TRS text resident set size, the amount of physical memory devoted to executable code.

tt TT controlling tty (terminal). (alias tname, tty).

tty TT controlling tty (terminal). (alias tname, tt).

ucmd CMD see comm. (alias comm, ucomm).

ucomm COMMAND see comm. (alias comm, ucmd).

uid UID see euid. (alias euid).

uname USER see euser. (alias euser, user).

unit UNIT displays unit which a process belongs to, if systemd support has been included.

user USER see euser. (alias euser, uname).

userns USERNS Unique inode number describing the namespace the process belongs to. See namespaces(7).

utsns UTSNS Unique inode number describing the namespace the process belongs to. See namespaces(7).

uunit UUNIT displays user unit which a process belongs to, if systemd support has been included.

vsize VSZ see vsz. (alias vsz).

vsz VSZ virtual memory size of the process in KiB (1024-byte units). Device mappings are currently excluded; this is subject to
change. (alias vsize).

wchan WCHAN name of the kernel function in which the process is sleeping, a "-" if the process is running, or a "*" if the process is
multi-threaded and ps is not displaying threads.

ENVIRONMENT VARIABLES

The following environment variables could affect ps:

       COLUMNS
          Override default display width.

       LINES
          Override default display height.

       PS_PERSONALITY
          Set to one of posix, old, linux, bsd, sun, digital... (see section PERSONALITY below).

       CMD_ENV
          Set to one of posix, old, linux, bsd, sun, digital... (see section PERSONALITY below).

       I_WANTABROKEN_PS
          Force obsolete command line interpretation.

       LC_TIME
          Date format.

       PS_COLORS
          Not currently supported.

       PS_FORMAT
          Default output format override.  You may set this to a format string of the type used for the -o option.  The DefSysV and DefBSD values are
          particularly useful.

       POSIXLY_CORRECT
          Don't find excuses to ignore bad "features".

       POSIX2
          When set to "on", acts as POSIXLY_CORRECT.

       UNIX95
          Don't find excuses to ignore bad "features".

       XPG
          Cancel CMDENV=irix non-standard behavior.

       In general, it is a bad idea to set these variables.  The one exception is CMD_ENV or PS_PERSONALITY, which could be set to Linux for normal
       systems.  Without that setting, ps follows the useless and bad parts of the Unix98 standard.

PERSONALITY

       390        like the OS/390 OpenEdition ps
       aix        like AIX ps
       bsd        like FreeBSD ps (totally non-standard)
       compaq     like Digital Unix ps
       debian     like the old Debian ps
       digital    like Tru64 (was Digital Unix, was OSF/1) ps
       gnu        like the old Debian ps
       hp         like HP-UX ps
       hpux       like HP-UX ps
       irix       like Irix ps
       linux      ***** recommended *****
       old        like the original Linux ps (totally non-standard)
       os390      like OS/390 Open Edition ps
       posix      standard
       s390       like OS/390 Open Edition ps
       sco        like SCO ps
       sgi        like Irix ps
       solaris2   like Solaris 2+ (SunOS 5) ps
       sunos4     like SunOS 4 (Solaris 1) ps (totally non-standard)
       svr4       standard
       sysv       standard
       tru64      like Tru64 (was Digital Unix, was OSF/1) ps
       unix       standard
       unix95     standard
       unix98     standard

SEE ALSO

pgrep(1), pstree(1), top(1), proc(5).

STANDARDS

This ps conforms to:

       1   Version 2 of the Single Unix Specification
       2   The Open Group Technical Standard Base Specifications, Issue 6
       3   IEEE Std 1003.1, 2004 Edition
       4   X/Open System Interfaces Extension [UP XSI]
       5   ISO/IEC 9945:2003

AUTHOR

       ps was originally written by Branko Lankester âź¨lankeste@fwi.uva.nlâź©.  Michael K. Johnson âź¨johnsonm@redhat.comâź© re-wrote it significantly to use
       the proc filesystem, changing a few things in the process.  Michael Shields âź¨mjshield@nyx.cs.du.eduâź© added the pid-list feature.  Charles Blake
       âź¨cblake@bbn.comâź© added multi-level sorting, the dirent-style library, the device name-to-number mmaped database, the approximate binary search
       directly on System.map, and many code and documentation cleanups.  David Mossberger-Tang wrote the generic BFD support for psupdate.  Albert
       Cahalan âź¨albert@users.sf.netâź© rewrote ps for full Unix98 and BSD support, along with some ugly hacks for obsolete and foreign syntax.

       Please send bug reports to âź¨procps@freelists.orgâź©.  No subscription is required or suggested.

procps-ng                                                              2020-06-04                                                                  PS(1)

Linux manpage

manpage rm

RM(1) User Commands RM(1)

NAME

rm – remove files or directories

SYNOPSIS

rm [OPTION]… [FILE]…

DESCRIPTION

This manual page documents the GNU version of rm. rm removes each specified file. By default, it does not remove directories.

       If the -I or --interactive=once option is given, and there are more than three files or the -r, -R, or --recursive are given, then rm prompts the
       user for whether to proceed with the entire operation.  If the response is not affirmative, the entire command is aborted.

       Otherwise, if a file is unwritable, standard input is a terminal, and the -f or --force option is not given, or the  -i  or  --interactive=always
       option is given, rm prompts the user for whether to remove the file.  If the response is not affirmative, the file is skipped.

OPTIONS

Remove (unlink) the FILE(s).

       -f, --force
              ignore nonexistent files and arguments, never prompt

       -i     prompt before every removal

       -I     prompt  once  before  removing  more than three files, or when removing recursively; less intrusive than -i, while still giving protection
              against most mistakes

       --interactive[=WHEN]
              prompt according to WHEN: never, once (-I), or always (-i); without WHEN, prompt always

       --one-file-system
              when removing a hierarchy recursively, skip any directory that is on a file system different from that of the corresponding  command  line
              argument

       --no-preserve-root
              do not treat '/' specially

       --preserve-root[=all]
              do not remove '/' (default); with 'all', reject any command line argument on a separate device from its parent

       -r, -R, --recursive
              remove directories and their contents recursively

       -d, --dir
              remove empty directories

       -v, --verbose
              explain what is being done

       --help display this help and exit

       --version
              output version information and exit

       By  default,  rm  does not remove directories.  Use the --recursive (-r or -R) option to remove each listed directory, too, along with all of its
       contents.

       To remove a file whose name starts with a '-', for example '-foo', use one of these commands:

              rm -- -foo

              rm ./-foo

       Note that if you use rm to remove a file, it might be possible to recover some of its contents, given  sufficient  expertise  and/or  time.   For
       greater assurance that the contents are truly unrecoverable, consider using shred.

AUTHOR

Written by Paul Rubin, David MacKenzie, Richard M. Stallman, and Jim Meyering.

REPORTING BUGS

       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
       Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT

       Copyright Â© 2020 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

unlink(1), unlink(2), chattr(1), shred(1)

       Full documentation <https://www.gnu.org/software/coreutils/rm>
       or available locally via: info '(coreutils) rm invocation'

GNU coreutils 8.32                                                   September 2020                                                                RM(1)

Linux manpage

manpage rsync

rsync(1) User Commands rsync(1)

NAME

rsync – a fast, versatile, remote (and local) file-copying tool

SYNOPSIS

Local: rsync [OPTION…] SRC… [DEST]

       Access via remote shell:
           Pull:
               rsync [OPTION...] [USER@]HOST:SRC... [DEST]
           Push:
               rsync [OPTION...] SRC... [USER@]HOST:DEST

       Access via rsync daemon:
           Pull:
               rsync [OPTION...] [USER@]HOST::SRC... [DEST]
               rsync [OPTION...] rsync://[USER@]HOST[:PORT]/SRC... [DEST]
           Push:
               rsync [OPTION...] SRC... [USER@]HOST::DEST
               rsync [OPTION...] SRC... rsync://[USER@]HOST[:PORT]/DEST)

       Usages with just one SRC arg and no DEST arg will list the source files instead of copying.

DESCRIPTION

       Rsync  is  a fast and extraordinarily versatile file copying tool.  It can copy locally, to/from another host over any remote shell, or to/from a
       remote rsync daemon.  It offers a large number of options that control every aspect of its behavior and permit very flexible specification of the
       set of files to be copied.  It is famous for its delta-transfer algorithm, which reduces the amount of data sent over the network by sending only
       the differences between the source files and the existing files in the destination.  Rsync is widely used for backups and mirroring and as an imâАР
       proved copy command for everyday use.

       Rsync  finds  files that need to be transferred using a "quick check" algorithm (by default) that looks for files that have changed in size or in
       last-modified time.  Any changes in the other preserved attributes (as requested by options) are made on the destination file directly  when  the
       quick check indicates that the file's data does not need to be updated.

       Some of the additional features of rsync are:

       o      support for copying links, devices, owners, groups, and permissions

       o      exclude and exclude-from options similar to GNU tar

       o      a CVS exclude mode for ignoring the same files that CVS would ignore

       o      can use any transparent remote shell, including ssh or rsh

       o      does not require super-user privileges

       o      pipelining of file transfers to minimize latency costs

       o      support for anonymous or authenticated rsync daemons (ideal for mirroring)

GENERAL

Rsync copies files either to or from a remote host, or locally on the current host (it does not support copying files between two remote hosts).

       There are two different ways for rsync to contact a remote system: using a remote-shell program as the transport (such as ssh or rsh) or contactâАР
       ing an rsync daemon directly via TCP.  The remote-shell transport is used whenever the source or destination path contains  a  single  colon  (:)
       separator  after  a  host specification.  Contacting an rsync daemon directly happens when the source or destination path contains a double colon
       (::) separator after a host specification, OR when an rsync:// URL is specified (see also the "USING RSYNC-DAEMON  FEATURES  VIA  A  REMOTE-SHELL
       CONNECTION" section for an exception to this latter rule).

       As a special case, if a single source arg is specified without a destination, the files are listed in an output format similar to "ls -l".

       As expected, if neither the source or destination path specify a remote host, the copy occurs locally (see also the --list-only option).

       Rsync refers to the local side as the client and the remote side as the server.  Don't confuse server with an rsync daemon.  A daemon is always a
       server, but a server can be either a daemon or a remote-shell spawned process.

SETUP

See the file README.md for installation instructions.

       Once installed, you can use rsync to any machine that you can access via a remote shell (as well as some that you can access using the rsync daeâАР
       mon-mode protocol).  For remote transfers, a modern rsync uses ssh for its communications, but it may have been configured to use a different reâАР
       mote shell by default, such as rsh or remsh.

       You can also specify any remote shell you like, either by using the -e command line option, or by setting the RSYNC_RSH environment variable.

       Note that rsync must be installed on both the source and destination machines.

USAGE

You use rsync in the same way you use rcp. You must specify a source and a destination, one of which may be remote.

Perhaps the best way to explain the syntax is with some examples:

rsync -t *.c foo:src/

This would transfer all files matching the pattern .c from the current directory to the directory src on the machine foo. If any of the files
already exist on the remote system then the rsync remote-update protocol is used to update the file by sending only the differences in the data.
Note that the expansion of wildcards on the command-line (.c) into a list of files is handled by the shell before it runs rsync and not by rsync
itself (exactly the same as all other Posix-style programs).

rsync -avz foo:src/bar /data/tmp

This would recursively transfer all files from the directory src/bar on the machine foo into the /data/tmp/bar directory on the local machine.
The files are transferred in archive mode, which ensures that symbolic links, devices, attributes, permissions, ownerships, etc. are preserved in
the transfer. Additionally, compression will be used to reduce the size of data portions of the transfer.

rsync -avz foo:src/bar/ /data/tmp

A trailing slash on the source changes this behavior to avoid creating an additional directory level at the destination. You can think of a
trailing / on a source as meaning "copy the contents of this directory" as opposed to "copy the directory by name", but in both cases the atâАР
tributes of the containing directory are transferred to the containing directory on the destination. In other words, each of the following comâАР
mands copies the files in the same way, including their setting of the attributes of /dest/foo:

rsync -av /src/foo /dest
rsync -av /src/foo/ /dest/foo

Note also that host and module references don't require a trailing slash to copy the contents of the default directory. For example, both of
these copy the remote directory's contents into "/dest":

rsync -av host: /dest
rsync -av host::module /dest

You can also use rsync in local-only mode, where both the source and destination don't have a ':' in the name. In this case it behaves like an
improved copy command.

Finally, you can list all the (listable) modules available from a particular rsync daemon by leaving off the module name:

rsync somehost.mydomain.com::

See the following section for more details.

ADVANCED USAGE

       The syntax for requesting multiple files from a remote host is done by specifying additional remote-host args in the same style as the first,  or
       with the hostname omitted.  For instance, all these work:

           rsync -av host:file1 :file2 host:file{3,4} /dest/
           rsync -av host::modname/file{1,2} host::modname/file3 /dest/
           rsync -av host::modname/file1 ::modname/file{3,4}

       Older versions of rsync required using quoted spaces in the SRC, like these examples:

           rsync -av host:'dir1/file1 dir2/file2' /dest
           rsync host::'modname/dir1/file1 modname/dir2/file2' /dest

       This word-splitting still works (by default) in the latest rsync, but is not as easy to use as the first method.

       If  you need to transfer a filename that contains whitespace, you can either specify the --protect-args (-s) option, or you'll need to escape the
       whitespace in a way that the remote shell will understand.  For instance:

           rsync -av host:'file\ name\ with\ spaces' /dest

CONNECTING TO AN RSYNC DAEMON

It is also possible to use rsync without a remote shell as the transport. In this case you will directly connect to a remote rsync daemon, typiâАР
cally using TCP port 873. (This obviously requires the daemon to be running on the remote system, so refer to the STARTING AN RSYNC DAEMON TO ACâАР
CEPT CONNECTIONS section below for information on that.)

Using rsync in this way is the same as using it with a remote shell except that:

o you either use a double colon :: instead of a single colon to separate the hostname from the path, or you use an rsync:// URL.

o the first word of the "path" is actually a module name.

o the remote daemon may print a message of the day when you connect.

o if you specify no path name on the remote daemon then the list of accessible paths on the daemon will be shown.

o if you specify no local destination then a listing of the specified files on the remote daemon is provided.

o you must not specify the --rsh (-e) option (since that overrides the daemon connection to use ssh -- see USING RSYNC-DAEMON FEATURES VIA A
REMOTE-SHELL CONNECTION below).

An example that copies all the files in a remote module named "src":

rsync -av host::src /dest

Some modules on the remote daemon may require authentication. If so, you will receive a password prompt when you connect. You can avoid the
password prompt by setting the environment variable RSYNC_PASSWORD to the password you want to use or using the --password-file option. This may
be useful when scripting rsync.

WARNING: On some systems environment variables are visible to all users. On those systems using --password-file is recommended.

You may establish the connection via a web proxy by setting the environment variable RSYNC_PROXY to a hostname:port pair pointing to your web
proxy. Note that your web proxy's configuration must support proxy connections to port 873.

You may also establish a daemon connection using a program as a proxy by setting the environment variable RSYNC_CONNECT_PROG to the commands you
wish to run in place of making a direct socket connection. The string may contain the escape "%H" to represent the hostname specified in the
rsync command (so use "%%" if you need a single "%" in your string). For example:

export RSYNC_CONNECT_PROG='ssh proxyhost nc %H 873'
rsync -av targethost1::module/src/ /dest/
rsync -av rsync://targethost2/module/src/ /dest/

The command specified above uses ssh to run nc (netcat) on a proxyhost, which forwards all data to port 873 (the rsync daemon) on the targethost
(%H).

Note also that if the RSYNC_SHELL environment variable is set, that program will be used to run the RSYNC_CONNECT_PROG command instead of using
the default shell of the system() call.

USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION

       It is sometimes useful to use various features of an rsync daemon (such as named modules) without actually allowing any  new  socket  connections
       into  a  system (other than what is already required to allow remote-shell access).  Rsync supports connecting to a host using a remote shell and
       then spawning a single-use "daemon" server that expects to read its config file in the home dir of the remote user.  This can be  useful  if  you
       want  to encrypt a daemon-style transfer's data, but since the daemon is started up fresh by the remote user, you may not be able to use features
       such as chroot or change the uid used by the daemon. (For another way to encrypt a daemon transfer, consider using ssh to tunnel a local port  to
       a remote machine and configure a normal rsync daemon on that remote host to only allow connections from "localhost".)

       From  the  user's  perspective, a daemon transfer via a remote-shell connection uses nearly the same command-line syntax as a normal rsync-daemon
       transfer, with the only exception being that you must explicitly set the remote shell program on the command-line with the --rsh=COMMAND  option.
       (Setting the RSYNC_RSH in the environment will not turn on this functionality.) For example:

           rsync -av --rsh=ssh host::module /dest

       If  you need to specify a different remote-shell user, keep in mind that the user@ prefix in front of the host is specifying the rsync-user value
       (for a module that requires user-based authentication).  This means that you must give the '-l user' option to ssh when  specifying  the  remote-
       shell, as in this example that uses the short version of the --rsh option:

           rsync -av -e "ssh -l ssh-user" rsync-user@host::module /dest

       The "ssh-user" will be used at the ssh level; the "rsync-user" will be used to log-in to the "module".

STARTING AN RSYNC DAEMON TO ACCEPT CONNECTIONS

       In  order  to connect to an rsync daemon, the remote system needs to have a daemon already running (or it needs to have configured something like
       inetd to spawn an rsync daemon for incoming connections on a particular port).  For full information on how to start a daemon that will  handling
       incoming  socket connections, see the rsyncd.conf(5) man page -- that is the config file for the daemon, and it contains the full details for how
       to run the daemon (including stand-alone and inetd configurations).

       If you're using one of the remote-shell transports for the transfer, there is no need to manually start an rsync daemon.

SORTED TRANSFER ORDER

       Rsync always sorts the specified filenames into its internal transfer list.  This handles the merging together of  the  contents  of  identically
       named  directories, makes it easy to remove duplicate filenames, and may confuse someone when the files are transferred in a different order than
       what was given on the command-line.

       If you need a particular file to be transferred prior to another, either separate the files into different rsync calls, or consider  using  --deâАР
       lay-updates (which doesn't affect the sorted transfer order, but does make the final file-updating phase happen much more rapidly).

EXAMPLES

Here are some examples of how I use rsync.

To backup my wife’s home directory, which consists of large MS Word files and mail folders, I use a cron job that runs

rsync -Cavz . arvidsjaur:backup

each night over a PPP connection to a duplicate directory on my machine “arvidsjaur”.

To synchronize my samba source trees I use the following Makefile targets:

get: rsync -avuzb –exclude ‘*~’ samba:samba/ .
put: rsync -Cavuzb . samba:samba/ sync: get put

       This  allows  me  to sync with a CVS directory at the other end of the connection.  I then do CVS operations on the remote machine, which saves a
       lot of time as the remote CVS protocol isn't very efficient.

       I mirror a directory between my "old" and "new" ftp sites with the command:

           rsync -az -e ssh --delete ~ftp/pub/samba nimbus:"~ftp/pub/tridge"

       This is launched from cron every few hours.

OPTION SUMMARY

Here is a short summary of the options available in rsync. Please refer to the detailed description below for a complete description.

       --verbose, -v            increase verbosity
       --info=FLAGS             fine-grained informational verbosity
       --debug=FLAGS            fine-grained debug verbosity
       --stderr=e|a|c           change stderr output mode (default: errors)
       --quiet, -q              suppress non-error messages
       --no-motd                suppress daemon-mode MOTD
       --checksum, -c           skip based on checksum, not mod-time & size
       --archive, -a            archive mode is -rlptgoD (no -A,-X,-U,-N,-H)
       --no-OPTION              turn off an implied OPTION (e.g. --no-D)
       --recursive, -r          recurse into directories
       --relative, -R           use relative path names
       --no-implied-dirs        don't send implied dirs with --relative
       --backup, -b             make backups (see --suffix & --backup-dir)
       --backup-dir=DIR         make backups into hierarchy based in DIR
       --suffix=SUFFIX          backup suffix (default ~ w/o --backup-dir)
       --update, -u             skip files that are newer on the receiver
       --inplace                update destination files in-place
       --append                 append data onto shorter files
       --append-verify          --append w/old data in file checksum
       --dirs, -d               transfer directories without recursing
       --mkpath                 create the destination's path component
       --links, -l              copy symlinks as symlinks
       --copy-links, -L         transform symlink into referent file/dir
       --copy-unsafe-links      only "unsafe" symlinks are transformed
       --safe-links             ignore symlinks that point outside the tree
       --munge-links            munge symlinks to make them safe & unusable
       --copy-dirlinks, -k      transform symlink to dir into referent dir
       --keep-dirlinks, -K      treat symlinked dir on receiver as dir
       --hard-links, -H         preserve hard links
       --perms, -p              preserve permissions
       --executability, -E      preserve executability
       --chmod=CHMOD            affect file and/or directory permissions
       --acls, -A               preserve ACLs (implies --perms)
       --xattrs, -X             preserve extended attributes
       --owner, -o              preserve owner (super-user only)
       --group, -g              preserve group
       --devices                preserve device files (super-user only)
       --copy-devices           copy device contents as regular file
       --specials               preserve special files
       -D                       same as --devices --specials
       --times, -t              preserve modification times
       --atimes, -U             preserve access (use) times
       --open-noatime           avoid changing the atime on opened files
       --crtimes, -N            preserve create times (newness)
       --omit-dir-times, -O     omit directories from --times
       --omit-link-times, -J    omit symlinks from --times
       --super                  receiver attempts super-user activities
       --fake-super             store/recover privileged attrs using xattrs
       --sparse, -S             turn sequences of nulls into sparse blocks
       --preallocate            allocate dest files before writing them
       --write-devices          write to devices as files (implies --inplace)
       --dry-run, -n            perform a trial run with no changes made
       --whole-file, -W         copy files whole (w/o delta-xfer algorithm)
       --checksum-choice=STR    choose the checksum algorithm (aka --cc)
       --one-file-system, -x    don't cross filesystem boundaries
       --block-size=SIZE, -B    force a fixed checksum block-size
       --rsh=COMMAND, -e        specify the remote shell to use
       --rsync-path=PROGRAM     specify the rsync to run on remote machine
       --existing               skip creating new files on receiver
       --ignore-existing        skip updating files that exist on receiver
       --remove-source-files    sender removes synchronized files (non-dir)
       --del                    an alias for --delete-during
       --delete                 delete extraneous files from dest dirs
       --delete-before          receiver deletes before xfer, not during
       --delete-during          receiver deletes during the transfer
       --delete-delay           find deletions during, delete after
       --delete-after           receiver deletes after transfer, not during
       --delete-excluded        also delete excluded files from dest dirs
       --ignore-missing-args    ignore missing source args without error
       --delete-missing-args    delete missing source args from destination
       --ignore-errors          delete even if there are I/O errors
       --force                  force deletion of dirs even if not empty
       --max-delete=NUM         don't delete more than NUM files
       --max-size=SIZE          don't transfer any file larger than SIZE
       --min-size=SIZE          don't transfer any file smaller than SIZE
       --max-alloc=SIZE         change a limit relating to memory alloc
       --partial                keep partially transferred files
       --partial-dir=DIR        put a partially transferred file into DIR
       --delay-updates          put all updated files into place at end
       --prune-empty-dirs, -m   prune empty directory chains from file-list
       --numeric-ids            don't map uid/gid values by user/group name
       --usermap=STRING         custom username mapping
       --groupmap=STRING        custom groupname mapping
       --chown=USER:GROUP       simple username/groupname mapping
       --timeout=SECONDS        set I/O timeout in seconds
       --contimeout=SECONDS     set daemon connection timeout in seconds
       --ignore-times, -I       don't skip files that match size and time
       --size-only              skip files that match in size
       --modify-window=NUM, -@  set the accuracy for mod-time comparisons
       --temp-dir=DIR, -T       create temporary files in directory DIR
       --fuzzy, -y              find similar file for basis if no dest file
       --compare-dest=DIR       also compare destination files relative to DIR
       --copy-dest=DIR          ... and include copies of unchanged files
       --link-dest=DIR          hardlink to files in DIR when unchanged
       --compress, -z           compress file data during the transfer
       --compress-choice=STR    choose the compression algorithm (aka --zc)
       --compress-level=NUM     explicitly set compression level (aka --zl)
       --skip-compress=LIST     skip compressing files with suffix in LIST
       --cvs-exclude, -C        auto-ignore files in the same way CVS does
       --filter=RULE, -f        add a file-filtering RULE
       -F                       same as --filter='dir-merge /.rsync-filter'
                                repeated: --filter='- .rsync-filter'
       --exclude=PATTERN        exclude files matching PATTERN
       --exclude-from=FILE      read exclude patterns from FILE
       --include=PATTERN        don't exclude files matching PATTERN
       --include-from=FILE      read include patterns from FILE
       --files-from=FILE        read list of source-file names from FILE
       --from0, -0              all -from/filter files are delimited by 0s
       --protect-args, -s       no space-splitting; wildcard chars only
       --copy-as=USER[:GROUP]   specify user & optional group for the copy
       --address=ADDRESS        bind address for outgoing socket to daemon
       --port=PORT              specify double-colon alternate port number
       --sockopts=OPTIONS       specify custom TCP options
       --blocking-io            use blocking I/O for the remote shell
       --outbuf=N|L|B           set out buffering to None, Line, or Block
       --stats                  give some file-transfer stats
       --8-bit-output, -8       leave high-bit chars unescaped in output
       --human-readable, -h     output numbers in a human-readable format
       --progress               show progress during transfer
       -P                       same as --partial --progress
       --itemize-changes, -i    output a change-summary for all updates
       --remote-option=OPT, -M  send OPTION to the remote side only
       --out-format=FORMAT      output updates using the specified FORMAT
       --log-file=FILE          log what we're doing to the specified FILE
       --log-file-format=FMT    log updates using the specified FMT
       --password-file=FILE     read daemon-access password from FILE
       --early-input=FILE       use FILE for daemon's early exec input
       --list-only              list the files instead of copying them
       --bwlimit=RATE           limit socket I/O bandwidth
       --stop-after=MINS        Stop rsync after MINS minutes have elapsed
       --stop-at=y-m-dTh:m      Stop rsync at the specified point in time
       --write-batch=FILE       write a batched update to FILE
       --only-write-batch=FILE  like --write-batch but w/o updating dest
       --read-batch=FILE        read a batched update from FILE
       --protocol=NUM           force an older protocol version to be used
       --iconv=CONVERT_SPEC     request charset conversion of filenames
       --checksum-seed=NUM      set block/file checksum seed (advanced)
       --ipv4, -4               prefer IPv4
       --ipv6, -6               prefer IPv6
       --version, -V            print the version + other info and exit
       --help, -h ()           show this help (* -h is help only on its own)

       Rsync can also be run as a daemon, in which case the following options are accepted:

       --daemon                 run as an rsync daemon
       --address=ADDRESS        bind to the specified address
       --bwlimit=RATE           limit socket I/O bandwidth
       --config=FILE            specify alternate rsyncd.conf file
       --dparam=OVERRIDE, -M    override global daemon config parameter
       --no-detach              do not detach from the parent
       --port=PORT              listen on alternate port number
       --log-file=FILE          override the "log file" setting
       --log-file-format=FMT    override the "log format" setting
       --sockopts=OPTIONS       specify custom TCP options
       --verbose, -v            increase verbosity
       --ipv4, -4               prefer IPv4
       --ipv6, -6               prefer IPv6
       --help, -h               show this help (when used with --daemon)

OPTIONS

Rsync accepts both long (double-dash + word) and short (single-dash + letter) options. The full list of the available options are described beâАР
low. If an option can be specified in more than one way, the choices are comma-separated. Some options only have a long variant, not a short.
If the option takes a parameter, the parameter is only listed after the long variant, even though it must also be specified for the short. When
specifying a parameter, you can either use the form --option=param or replace the '=' with whitespace. The parameter may need to be quoted in
some manner for it to survive the shell's command-line parsing. Keep in mind that a leading tilde (~) in a filename is substituted by your
shell, so --option=~/foo will not change the tilde into your home directory (remove the '=' for that).

--help, -h ()
Print a short help page describing the options available in rsync and exit. () The -h short option will only invoke --help when used
without other options since it normally means --human-readable.

--version, -V
Print the rsync version plus other info and exit.

The output includes the default list of checksum algorithms, the default list of compression algorithms, a list of compiled-in capabiliâАР
ties, a link to the rsync web site, and some license/copyright info.

--verbose, -v
This option increases the amount of information you are given during the transfer. By default, rsync works silently. A single -v will
give you information about what files are being transferred and a brief summary at the end. Two -v options will give you information on
what files are being skipped and slightly more information at the end. More than two -v options should only be used if you are debugging
rsync.

In a modern rsync, the -v option is equivalent to the setting of groups of --info and --debug options. You can choose to use these newer
options in addition to, or in place of using --verbose, as any fine-grained settings override the implied settings of -v. Both --info and
--debug have a way to ask for help that tells you exactly what flags are set for each increase in verbosity.

However, do keep in mind that a daemon's "max verbosity" setting will limit how high of a level the various individual flags can be set on
the daemon side. For instance, if the max is 2, then any info and/or debug flag that is set to a higher value than what would be set by
-vv will be downgraded to the -vv level in the daemon's logging.

--info=FLAGS
This option lets you have fine-grained control over the information output you want to see. An individual flag name may be followed by a
level number, with 0 meaning to silence that output, 1 being the default output level, and higher numbers increasing the output of that
flag (for those that support higher levels). Use --info=help to see all the available flag names, what they output, and what flag names
are added for each increase in the verbose level. Some examples:

rsync -a --info=progress2 src/ dest/
rsync -avv --info=stats2,misc1,flist0 src/ dest/

Note that --info=name's output is affected by the --out-format and --itemize-changes (-i) options. See those options for more information
on what is output and when.

This option was added to 3.1.0, so an older rsync on the server side might reject your attempts at fine-grained control (if one or more
flags needed to be send to the server and the server was too old to understand them). See also the "max verbosity" caveat above when
dealing with a daemon.

--debug=FLAGS
This option lets you have fine-grained control over the debug output you want to see. An individual flag name may be followed by a level
number, with 0 meaning to silence that output, 1 being the default output level, and higher numbers increasing the output of that flag
(for those that support higher levels). Use --debug=help to see all the available flag names, what they output, and what flag names are
added for each increase in the verbose level. Some examples:

rsync -avvv --debug=none src/ dest/
rsync -avA --del --debug=del2,acl src/ dest/

Note that some debug messages will only be output when --stderr=all is specified, especially those pertaining to I/O and buffer debugging.

Beginning in 3.2.0, this option is no longer auto-forwarded to the server side in order to allow you to specify different debug values for
each side of the transfer, as well as to specify a new debug option that is only present in one of the rsync versions. If you want to duâАР
plicate the same option on both sides, using brace expansion is an easy way to save you some typing. This works in zsh and bash:

rsync -aiv {-M,}--debug=del2 src/ dest/

--stderr=errors|all|client
This option controls which processes output to stderr and if info messages are also changed to stderr. The mode strings can be abbreviâАР
ated, so feel free to use a single letter value. The 3 possible choices are:

o errors - (the default) causes all the rsync processes to send an error directly to stderr, even if the process is on the remote
side of the transfer. Info messages are sent to the client side via the protocol stream. If stderr is not available (i.e. when
directly connecting with a daemon via a socket) errors fall back to being sent via the protocol stream.

o all - causes all rsync messages (info and error) to get written directly to stderr from all (possible) processes. This causes
stderr to become line-buffered (instead of raw) and eliminates the ability to divide up the info and error messages by file handle.
For those doing debugging or using several levels of verbosity, this option can help to avoid clogging up the transfer stream
(which should prevent any chance of a deadlock bug hanging things up). It also allows --debug to enable some extra I/O related
messages.

o client - causes all rsync messages to be sent to the client side via the protocol stream. One client process outputs all messages,
with errors on stderr and info messages on stdout. This was the default in older rsync versions, but can cause error delays when a
lot of transfer data is ahead of the messages. If you're pushing files to an older rsync, you may want to use --stderr=all since
that idiom has been around for several releases.

This option was added in rsync 3.2.3. This version also began the forwarding of a non-default setting to the remote side, though rsync
uses the backward-compatible options --msgs2stderr and --no-msgs2stderr to represent the all and client settings, respectively. A newer
rsync will continue to accept these older option names to maintain compatibility.

--quiet, -q
This option decreases the amount of information you are given during the transfer, notably suppressing information messages from the reâАР
mote server. This option is useful when invoking rsync from cron.

--no-motd
This option affects the information that is output by the client at the start of a daemon transfer. This suppresses the message-of-the-
day (MOTD) text, but it also affects the list of modules that the daemon sends in response to the "rsync host::" request (due to a limitaâАР
tion in the rsync protocol), so omit this option if you want to request the list of modules from the daemon.

--ignore-times, -I
Normally rsync will skip any files that are already the same size and have the same modification timestamp. This option turns off this
"quick check" behavior, causing all files to be updated.

--size-only
This modifies rsync's "quick check" algorithm for finding files that need to be transferred, changing it from the default of transferring
files with either a changed size or a changed last-modified time to just looking for files that have changed in size. This is useful when
starting to use rsync after using another mirroring system which may not preserve timestamps exactly.

--modify-window=NUM, -@
When comparing two timestamps, rsync treats the timestamps as being equal if they differ by no more than the modify-window value. The deâАР
fault is 0, which matches just integer seconds. If you specify a negative value (and the receiver is at least version 3.1.3) then
nanoseconds will also be taken into account. Specifying 1 is useful for copies to/from MS Windows FAT filesystems, because FAT represents
times with a 2-second resolution (allowing times to differ from the original by up to 1 second).

If you want all your transfers to default to comparing nanoseconds, you can create a ~/.popt file and put these lines in it:

rsync alias -a -a@-1
rsync alias -t -t@-1

With that as the default, you'd need to specify --modify-window=0 (aka -@0) to override it and ignore nanoseconds, e.g. if you're copying
between ext3 and ext4, or if the receiving rsync is older than 3.1.3.

--checksum, -c
This changes the way rsync checks if the files have been changed and are in need of a transfer. Without this option, rsync uses a "quick
check" that (by default) checks if each file's size and time of last modification match between the sender and receiver. This option
changes this to compare a 128-bit checksum for each file that has a matching size. Generating the checksums means that both sides will
expend a lot of disk I/O reading all the data in the files in the transfer, so this can slow things down significantly (and this is prior
to any reading that will be done to transfer changed files)

The sending side generates its checksums while it is doing the file-system scan that builds the list of the available files. The receiver
generates its checksums when it is scanning for changed files, and will checksum any file that has the same size as the corresponding
sender's file: files with either a changed size or a changed checksum are selected for transfer.

Note that rsync always verifies that each transferred file was correctly reconstructed on the receiving side by checking a whole-file
checksum that is generated as the file is transferred, but that automatic after-the-transfer verification has nothing to do with this opâАР
tion's before-the-transfer "Does this file need to be updated?" check.

The checksum used is auto-negotiated between the client and the server, but can be overridden using either the --checksum-choice (--cc)
option or an environment variable that is discussed in that option's section.

--archive, -a
This is equivalent to -rlptgoD. It is a quick way of saying you want recursion and want to preserve almost everything. Be aware that it
does not include preserving ACLs (-A), xattrs (-X), atimes (-U), crtimes (-N), nor the finding and preserving of hardlinks (-H).

The only exception to the above equivalence is when --files-from is specified, in which case -r is not implied.

--no-OPTION
You may turn off one or more implied options by prefixing the option name with "no-". Not all options may be prefixed with a "no-": only
options that are implied by other options (e.g. --no-D, --no-perms) or have different defaults in various circumstances (e.g. --no-whole-
file, --no-blocking-io, --no-dirs). You may specify either the short or the long option name after the "no-" prefix (e.g. --no-R is the
same as --no-relative).

For example: if you want to use -a (--archive) but don't want -o (--owner), instead of converting -a into -rlptgD, you could specify
-a --no-o (or -a --no-owner).

The order of the options is important: if you specify --no-r -a, the -r option would end up being turned on, the opposite of -a --no-r.
Note also that the side-effects of the --files-from option are NOT positional, as it affects the default state of several options and
slightly changes the meaning of -a (see the --files-from option for more details).

--recursive, -r
This tells rsync to copy directories recursively. See also --dirs (-d).

Beginning with rsync 3.0.0, the recursive algorithm used is now an incremental scan that uses much less memory than before and begins the
transfer after the scanning of the first few directories have been completed. This incremental scan only affects our recursion algorithm,
and does not change a non-recursive transfer. It is also only possible when both ends of the transfer are at least version 3.0.0.

Some options require rsync to know the full file list, so these options disable the incremental recursion mode. These include: --delete-
before, --delete-after, --prune-empty-dirs, and --delay-updates. Because of this, the default delete mode when you specify --delete is
now --delete-during when both ends of the connection are at least 3.0.0 (use --del or --delete-during to request this improved deletion
mode explicitly). See also the --delete-delay option that is a better choice than using --delete-after.

Incremental recursion can be disabled using the --no-inc-recursive option or its shorter --no-i-r alias.

--relative, -R
Use relative paths. This means that the full path names specified on the command line are sent to the server rather than just the last
parts of the filenames. This is particularly useful when you want to send several different directories at the same time. For example,
if you used this command:

rsync -av /foo/bar/baz.c remote:/tmp/

would create a file named baz.c in /tmp/ on the remote machine. If instead you used

rsync -avR /foo/bar/baz.c remote:/tmp/

then a file named /tmp/foo/bar/baz.c would be created on the remote machine, preserving its full path. These extra path elements are
called "implied directories" (i.e. the "foo" and the "foo/bar" directories in the above example).

Beginning with rsync 3.0.0, rsync always sends these implied directories as real directories in the file list, even if a path element is
really a symlink on the sending side. This prevents some really unexpected behaviors when copying the full path of a file that you didn't
realize had a symlink in its path. If you want to duplicate a server-side symlink, include both the symlink via its path, and referent
directory via its real path. If you're dealing with an older rsync on the sending side, you may need to use the --no-implied-dirs option.

It is also possible to limit the amount of path information that is sent as implied directories for each path you specify. With a modern
rsync on the sending side (beginning with 2.6.7), you can insert a dot and a slash into the source path, like this:

rsync -avR /foo/./bar/baz.c remote:/tmp/

That would create /tmp/bar/baz.c on the remote machine. (Note that the dot must be followed by a slash, so "/foo/." would not be abbreviâАР
ated.) For older rsync versions, you would need to use a chdir to limit the source path. For example, when pushing files:

(cd /foo; rsync -avR bar/baz.c remote:/tmp/)

(Note that the parens put the two commands into a sub-shell, so that the "cd" command doesn't remain in effect for future commands.) If
you're pulling files from an older rsync, use this idiom (but only for a non-daemon transfer):

rsync -avR --rsync-path="cd /foo; rsync" \
remote:bar/baz.c /tmp/

--no-implied-dirs
This option affects the default behavior of the --relative option. When it is specified, the attributes of the implied directories from
the source names are not included in the transfer. This means that the corresponding path elements on the destination system are left unâАР
changed if they exist, and any missing implied directories are created with default attributes. This even allows these implied path eleâАР
ments to have big differences, such as being a symlink to a directory on the receiving side.

For instance, if a command-line arg or a files-from entry told rsync to transfer the file "path/foo/file", the directories "path" and
"path/foo" are implied when --relative is used. If "path/foo" is a symlink to "bar" on the destination system, the receiving rsync would
ordinarily delete "path/foo", recreate it as a directory, and receive the file into the new directory. With --no-implied-dirs, the reâАР
ceiving rsync updates "path/foo/file" using the existing path elements, which means that the file ends up being created in "path/bar".
Another way to accomplish this link preservation is to use the --keep-dirlinks option (which will also affect symlinks to directories in
the rest of the transfer).

When pulling files from an rsync older than 3.0.0, you may need to use this option if the sending side has a symlink in the path you reâАР
quest and you wish the implied directories to be transferred as normal directories.

--backup, -b
With this option, preexisting destination files are renamed as each file is transferred or deleted. You can control where the backup file
goes and what (if any) suffix gets appended using the --backup-dir and --suffix options.

Note that if you don't specify --backup-dir, (1) the --omit-dir-times option will be forced on, and (2) if --delete is also in effect
(without --delete-excluded), rsync will add a "protect" filter-rule for the backup suffix to the end of all your existing excludes (e.g.
-f "P *~"). This will prevent previously backed-up files from being deleted. Note that if you are supplying your own filter rules, you
may need to manually insert your own exclude/protect rule somewhere higher up in the list so that it has a high enough priority to be efâАР
fective (e.g., if your rules specify a trailing inclusion/exclusion of *, the auto-added rule would never be reached).

--backup-dir=DIR
This implies the --backup option, and tells rsync to store all backups in the specified directory on the receiving side. This can be used
for incremental backups. You can additionally specify a backup suffix using the --suffix option (otherwise the files backed up in the
specified directory will keep their original filenames).

Note that if you specify a relative path, the backup directory will be relative to the destination directory, so you probably want to
specify either an absolute path or a path that starts with "../". If an rsync daemon is the receiver, the backup dir cannot go outside
the module's path hierarchy, so take extra care not to delete it or copy into it.

--suffix=SUFFIX
This option allows you to override the default backup suffix used with the --backup (-b) option. The default suffix is a ~ if no
--backup-dir was specified, otherwise it is an empty string.

--update, -u
This forces rsync to skip any files which exist on the destination and have a modified time that is newer than the source file. (If an exâАР
isting destination file has a modification time equal to the source file's, it will be updated if the sizes are different.)

Note that this does not affect the copying of dirs, symlinks, or other special files. Also, a difference of file format between the
sender and receiver is always considered to be important enough for an update, no matter what date is on the objects. In other words, if
the source has a directory where the destination has a file, the transfer would occur regardless of the timestamps.

This option is a transfer rule, not an exclude, so it doesn't affect the data that goes into the file-lists, and thus it doesn't affect
deletions. It just limits the files that the receiver requests to be transferred.

--inplace
This option changes how rsync transfers a file when its data needs to be updated: instead of the default method of creating a new copy of
the file and moving it into place when it is complete, rsync instead writes the updated data directly to the destination file.

This has several effects:

o Hard links are not broken. This means the new data will be visible through other hard links to the destination file. Moreover,
attempts to copy differing source files onto a multiply-linked destination file will result in a "tug of war" with the destination
data changing back and forth.

o In-use binaries cannot be updated (either the OS will prevent this from happening, or binaries that attempt to swap-in their data
will misbehave or crash).

o The file's data will be in an inconsistent state during the transfer and will be left that way if the transfer is interrupted or if
an update fails.

o A file that rsync cannot write to cannot be updated. While a super user can update any file, a normal user needs to be granted
write permission for the open of the file for writing to be successful.

o The efficiency of rsync's delta-transfer algorithm may be reduced if some data in the destination file is overwritten before it can
be copied to a position later in the file. This does not apply if you use --backup, since rsync is smart enough to use the backup
file as the basis file for the transfer.

WARNING: you should not use this option to update files that are being accessed by others, so be careful when choosing to use this for a
copy.

This option is useful for transferring large files with block-based changes or appended data, and also on systems that are disk bound, not
network bound. It can also help keep a copy-on-write filesystem snapshot from diverging the entire contents of a file that only has minor
changes.

The option implies --partial (since an interrupted transfer does not delete the file), but conflicts with --partial-dir and --delay-upâАР
dates. Prior to rsync 2.6.4 --inplace was also incompatible with --compare-dest and --link-dest.

--append
This special copy mode only works to efficiently update files that are known to be growing larger where any existing content on the reâАР
ceiving side is also known to be the same as the content on the sender. The use of --append can be dangerous if you aren't 100% sure that
all the files in the transfer are shared, growing files. You should thus use filter rules to ensure that you weed out any files that do
not fit this criteria.

Rsync updates these growing file in-place without verifying any of the existing content in the file (it only verifies the content that it
is appending). Rsync skips any files that exist on the receiving side that are not shorter than the associated file on the sending side
(which means that new files are transferred).

This does not interfere with the updating of a file's non-content attributes (e.g. permissions, ownership, etc.) when the file does not
need to be transferred, nor does it affect the updating of any directories or non-regular files.

--append-verify
This special copy mode works like --append except that all the data in the file is included in the checksum verification (making it much
less efficient but also potentially safer). This option can be dangerous if you aren't 100% sure that all the files in the transfer are
shared, growing files. See the --append option for more details.

Note: prior to rsync 3.0.0, the --append option worked like --append-verify, so if you are interacting with an older rsync (or the transâАР
fer is using a protocol prior to 30), specifying either append option will initiate an --append-verify transfer.

--dirs, -d
Tell the sending side to include any directories that are encountered. Unlike --recursive, a directory's contents are not copied unless
the directory name specified is "." or ends with a trailing slash (e.g. ".", "dir/.", "dir/", etc.). Without this option or the --recurâАР
sive option, rsync will skip all directories it encounters (and output a message to that effect for each one). If you specify both --dirs
and --recursive, --recursive takes precedence.

The --dirs option is implied by the --files-from option or the --list-only option (including an implied --list-only usage) if --recursive
wasn't specified (so that directories are seen in the listing). Specify --no-dirs (or --no-d) if you want to turn this off.

There is also a backward-compatibility helper option, --old-dirs (or --old-d) that tells rsync to use a hack of -r --exclude='/*/*' to get
an older rsync to list a single directory without recursing.

--mkpath
Create a missing path component of the destination arg. This allows rsync to create multiple levels of missing destination dirs and to
create a path in which to put a single renamed file. Keep in mind that you'll need to supply a trailing slash if you want the entire desâАР
tination path to be treated as a directory when copying a single arg (making rsync behave the same way that it would if the path component
of the destination had already existed).

For example, the following creates a copy of file foo as bar in the sub/dir directory, creating dirs "sub" and "sub/dir" if either do not
yet exist:

rsync -ai --mkpath foo sub/dir/bar

If you instead ran the following, it would have created file foo in the sub/dir/bar directory:

rsync -ai --mkpath foo sub/dir/bar/

--links, -l
When symlinks are encountered, recreate the symlink on the destination.

--copy-links, -L
When symlinks are encountered, the item that they point to (the referent) is copied, rather than the symlink. In older versions of rsync,
this option also had the side-effect of telling the receiving side to follow symlinks, such as symlinks to directories. In a modern rsync
such as this one, you'll need to specify --keep-dirlinks (-K) to get this extra behavior. The only exception is when sending files to an
rsync that is too old to understand -K -- in that case, the -L option will still have the side-effect of -K on that older receiving rsync.

--copy-unsafe-links
This tells rsync to copy the referent of symbolic links that point outside the copied tree. Absolute symlinks are also treated like ordiâАР
nary files, and so are any symlinks in the source path itself when --relative is used. This option has no additional effect if --copy-
links was also specified.

Note that the cut-off point is the top of the transfer, which is the part of the path that rsync isn't mentioning in the verbose output.
If you copy "/src/subdir" to "/dest/" then the "subdir" directory is a name inside the transfer tree, not the top of the transfer (which
is /src) so it is legal for created relative symlinks to refer to other names inside the /src and /dest directories. If you instead copy
"/src/subdir/" (with a trailing slash) to "/dest/subdir" that would not allow symlinks to any files outside of "subdir".

--safe-links
This tells rsync to ignore any symbolic links which point outside the copied tree. All absolute symlinks are also ignored. Using this opâАР
tion in conjunction with --relative may give unexpected results.

--munge-links
This option tells rsync to (1) modify all symlinks on the receiving side in a way that makes them unusable but recoverable (see below), or
(2) to unmunge symlinks on the sending side that had been stored in a munged state. This is useful if you don't quite trust the source of
the data to not try to slip in a symlink to a unexpected place.

The way rsync disables the use of symlinks is to prefix each one with the string "/rsyncd-munged/". This prevents the links from being
used as long as that directory does not exist. When this option is enabled, rsync will refuse to run if that path is a directory or a
symlink to a directory.

The option only affects the client side of the transfer, so if you need it to affect the server, specify it via --remote-option. (Note
that in a local transfer, the client side is the sender.)

This option has no affect on a daemon, since the daemon configures whether it wants munged symlinks via its "munge symlinks" parameter.
See also the "munge-symlinks" perl script in the support directory of the source code.

--copy-dirlinks, -k
This option causes the sending side to treat a symlink to a directory as though it were a real directory. This is useful if you don't
want symlinks to non-directories to be affected, as they would be using --copy-links.

Without this option, if the sending side has replaced a directory with a symlink to a directory, the receiving side will delete anything
that is in the way of the new symlink, including a directory hierarchy (as long as --force or --delete is in effect).

See also --keep-dirlinks for an analogous option for the receiving side.

--copy-dirlinks applies to all symlinks to directories in the source. If you want to follow only a few specified symlinks, a trick you
can use is to pass them as additional source args with a trailing slash, using --relative to make the paths match up right. For example:

rsync -r --relative src/./ src/./follow-me/ dest/

This works because rsync calls lstat(2) on the source arg as given, and the trailing slash makes lstat(2) follow the symlink, giving rise
to a directory in the file-list which overrides the symlink found during the scan of "src/./".

--keep-dirlinks, -K
This option causes the receiving side to treat a symlink to a directory as though it were a real directory, but only if it matches a real
directory from the sender. Without this option, the receiver's symlink would be deleted and replaced with a real directory.

For example, suppose you transfer a directory "foo" that contains a file "file", but "foo" is a symlink to directory "bar" on the reâАР
ceiver. Without --keep-dirlinks, the receiver deletes symlink "foo", recreates it as a directory, and receives the file into the new diâАР
rectory. With --keep-dirlinks, the receiver keeps the symlink and "file" ends up in "bar".

One note of caution: if you use --keep-dirlinks, you must trust all the symlinks in the copy! If it is possible for an untrusted user to
create their own symlink to any directory, the user could then (on a subsequent copy) replace the symlink with a real directory and affect
the content of whatever directory the symlink references. For backup copies, you are better off using something like a bind mount instead
of a symlink to modify your receiving hierarchy.

See also --copy-dirlinks for an analogous option for the sending side.

--hard-links, -H
This tells rsync to look for hard-linked files in the source and link together the corresponding files on the destination. Without this
option, hard-linked files in the source are treated as though they were separate files.

This option does NOT necessarily ensure that the pattern of hard links on the destination exactly matches that on the source. Cases in
which the destination may end up with extra hard links include the following:

o If the destination contains extraneous hard-links (more linking than what is present in the source file list), the copying algoâАР
rithm will not break them explicitly. However, if one or more of the paths have content differences, the normal file-update
process will break those extra links (unless you are using the --inplace option).

o If you specify a --link-dest directory that contains hard links, the linking of the destination files against the --link-dest files
can cause some paths in the destination to become linked together due to the --link-dest associations.

Note that rsync can only detect hard links between files that are inside the transfer set. If rsync updates a file that has extra hard-
link connections to files outside the transfer, that linkage will be broken. If you are tempted to use the --inplace option to avoid this
breakage, be very careful that you know how your files are being updated so that you are certain that no unintended changes happen due to
lingering hard links (and see the --inplace option for more caveats).

If incremental recursion is active (see --recursive), rsync may transfer a missing hard-linked file before it finds that another link for
that contents exists elsewhere in the hierarchy. This does not affect the accuracy of the transfer (i.e. which files are hard-linked toâАР
gether), just its efficiency (i.e. copying the data for a new, early copy of a hard-linked file that could have been found later in the
transfer in another member of the hard-linked set of files). One way to avoid this inefficiency is to disable incremental recursion using
the --no-inc-recursive option.

--perms, -p
This option causes the receiving rsync to set the destination permissions to be the same as the source permissions. (See also the --chmod
option for a way to modify what rsync considers to be the source permissions.)

When this option is off, permissions are set as follows:

o Existing files (including updated files) retain their existing permissions, though the --executability option might change just the
execute permission for the file.

o New files get their "normal" permission bits set to the source file's permissions masked with the receiving directory's default
permissions (either the receiving process's umask, or the permissions specified via the destination directory's default ACL), and
their special permission bits disabled except in the case where a new directory inherits a setgid bit from its parent directory.

Thus, when --perms and --executability are both disabled, rsync's behavior is the same as that of other file-copy utilities, such as cp(1)
and tar(1).

In summary: to give destination files (both old and new) the source permissions, use --perms. To give new files the destination-default
permissions (while leaving existing files unchanged), make sure that the --perms option is off and use --chmod=ugo=rwX (which ensures that
all non-masked bits get enabled). If you'd care to make this latter behavior easier to type, you could define a popt alias for it, such
as putting this line in the file ~/.popt (the following defines the -Z option, and includes --no-g to use the default group of the destiâАР
nation dir):

rsync alias -Z --no-p --no-g --chmod=ugo=rwX

You could then use this new option in a command such as this one:

rsync -avZ src/ dest/

(Caveat: make sure that -a does not follow -Z, or it will re-enable the two --no-* options mentioned above.)

The preservation of the destination's setgid bit on newly-created directories when --perms is off was added in rsync 2.6.7. Older rsync
versions erroneously preserved the three special permission bits for newly-created files when --perms was off, while overriding the destiâАР
nation's setgid bit setting on a newly-created directory. Default ACL observance was added to the ACL patch for rsync 2.6.7, so older (or
non-ACL-enabled) rsyncs use the umask even if default ACLs are present. (Keep in mind that it is the version of the receiving rsync that
affects these behaviors.)

--executability, -E
This option causes rsync to preserve the executability (or non-executability) of regular files when --perms is not enabled. A regular
file is considered to be executable if at least one 'x' is turned on in its permissions. When an existing destination file's executabilâАР
ity differs from that of the corresponding source file, rsync modifies the destination file's permissions as follows:

o To make a file non-executable, rsync turns off all its 'x' permissions.

o To make a file executable, rsync turns on each 'x' permission that has a corresponding 'r' permission enabled.

If --perms is enabled, this option is ignored.

--acls, -A
This option causes rsync to update the destination ACLs to be the same as the source ACLs. The option also implies --perms.

The source and destination systems must have compatible ACL entries for this option to work properly. See the --fake-super option for a
way to backup and restore ACLs that are not compatible.

--xattrs, -X
This option causes rsync to update the destination extended attributes to be the same as the source ones.

For systems that support extended-attribute namespaces, a copy being done by a super-user copies all namespaces except system.. A normal
user only copies the user. namespace. To be able to backup and restore non-user namespaces as a normal user, see the --fake-super opâАР
tion.

The above name filtering can be overridden by using one or more filter options with the x modifier. When you specify an xattr-affecting
filter rule, rsync requires that you do your own system/user filtering, as well as any additional filtering for what xattr names are
copied and what names are allowed to be deleted. For example, to skip the system namespace, you could specify:

--filter='-x system.*'

To skip all namespaces except the user namespace, you could specify a negated-user match:

--filter='-x! user.*'

To prevent any attributes from being deleted, you could specify a receiver-only rule that excludes all names:

--filter='-xr *'

Note that the -X option does not copy rsync's special xattr values (e.g. those used by --fake-super) unless you repeat the option (e.g.
-XX). This "copy all xattrs" mode cannot be used with --fake-super.

--chmod=CHMOD
This option tells rsync to apply one or more comma-separated "chmod" modes to the permission of the files in the transfer. The resulting
value is treated as though it were the permissions that the sending side supplied for the file, which means that this option can seem to
have no effect on existing files if --perms is not enabled.

In addition to the normal parsing rules specified in the chmod(1) manpage, you can specify an item that should only apply to a directory
by prefixing it with a 'D', or specify an item that should only apply to a file by prefixing it with a 'F'. For example, the following
will ensure that all directories get marked set-gid, that no files are other-writable, that both are user-writable and group-writable, and
that both have consistent executability across all bits:

--chmod=Dg+s,ug+w,Fo-w,+X

Using octal mode numbers is also allowed:

--chmod=D2775,F664

It is also legal to specify multiple --chmod options, as each additional option is just appended to the list of changes to make.

See the --perms and --executability options for how the resulting permission value can be applied to the files in the transfer.

--owner, -o
This option causes rsync to set the owner of the destination file to be the same as the source file, but only if the receiving rsync is
being run as the super-user (see also the --super and --fake-super options). Without this option, the owner of new and/or transferred
files are set to the invoking user on the receiving side.

The preservation of ownership will associate matching names by default, but may fall back to using the ID number in some circumstances
(see also the --numeric-ids option for a full discussion).

--group, -g
This option causes rsync to set the group of the destination file to be the same as the source file. If the receiving program is not runâАР
ning as the super-user (or if --no-super was specified), only groups that the invoking user on the receiving side is a member of will be
preserved. Without this option, the group is set to the default group of the invoking user on the receiving side.

The preservation of group information will associate matching names by default, but may fall back to using the ID number in some circumâАР
stances (see also the --numeric-ids option for a full discussion).

--devices
This option causes rsync to transfer character and block device files to the remote system to recreate these devices. This option has no
effect if the receiving rsync is not run as the super-user (see also the --super and --fake-super options).

--specials
This option causes rsync to transfer special files such as named sockets and fifos.

-D The -D option is equivalent to --devices --specials.

--write-devices
This tells rsync to treat a device on the receiving side as a regular file, allowing the writing of file data into a device.

This option implies the --inplace option.

Be careful using this, as you should know what devices are present on the receiving side of the transfer, especially if running rsync as
root.

This option is refused by an rsync daemon.

--times, -t
This tells rsync to transfer modification times along with the files and update them on the remote system. Note that if this option is
not used, the optimization that excludes files that have not been modified cannot be effective; in other words, a missing -t or -a will
cause the next transfer to behave as if it used -I, causing all files to be updated (though rsync's delta-transfer algorithm will make the
update fairly efficient if the files haven't actually changed, you're much better off using -t).

--atimes, -U
This tells rsync to set the access (use) times of the destination files to the same value as the source files.

If repeated, it also sets the --open-noatime option, which can help you to make the sending and receiving systems have the same access
times on the transferred files without needing to run rsync an extra time after a file is transferred.

Note that some older rsync versions (prior to 3.2.0) may have been built with a pre-release --atimes patch that does not imply --open-noaâАР
time when this option is repeated.

--open-noatime
This tells rsync to open files with the O_NOATIME flag (on systems that support it) to avoid changing the access time of the files that
are being transferred. If your OS does not support the O_NOATIME flag then rsync will silently ignore this option. Note also that some
filesystems are mounted to avoid updating the atime on read access even without the O_NOATIME flag being set.

--crtimes, -N,
This tells rsync to set the create times (newness) of the destination files to the same value as the source files.

--omit-dir-times, -O
This tells rsync to omit directories when it is preserving modification times (see --times). If NFS is sharing the directories on the reâАР
ceiving side, it is a good idea to use -O. This option is inferred if you use --backup without --backup-dir.

This option also has the side-effect of avoiding early creation of directories in incremental recursion copies. The default --inc-recurâАР
sive copying normally does an early-create pass of all the sub-directories in a parent directory in order for it to be able to then set
the modify time of the parent directory right away (without having to delay that until a bunch of recursive copying has finished). This
early-create idiom is not necessary if directory modify times are not being preserved, so it is skipped. Since early-create directories
don't have accurate mode, mtime, or ownership, the use of this option can help when someone wants to avoid these partially-finished direcâАР
tories.

--omit-link-times, -J
This tells rsync to omit symlinks when it is preserving modification times (see --times).

--super
This tells the receiving side to attempt super-user activities even if the receiving rsync wasn't run by the super-user. These activities
include: preserving users via the --owner option, preserving all groups (not just the current user's groups) via the --group option, and
copying devices via the --devices option. This is useful for systems that allow such activities without being the super-user, and also
for ensuring that you will get errors if the receiving side isn't being run as the super-user. To turn off super-user activities, the suâАР
per-user can use --no-super.

--fake-super
When this option is enabled, rsync simulates super-user activities by saving/restoring the privileged attributes via special extended atâАР
tributes that are attached to each file (as needed). This includes the file's owner and group (if it is not the default), the file's deâАР
vice info (device & special files are created as empty text files), and any permission bits that we won't allow to be set on the real file
(e.g. the real file gets u-s,g-s,o-t for safety) or that would limit the owner's access (since the real super-user can always acâАР
cess/change a file, the files we create can always be accessed/changed by the creating user). This option also handles ACLs (if --acls
was specified) and non-user extended attributes (if --xattrs was specified).

This is a good way to backup data without using a super-user, and to store ACLs from incompatible systems.

The --fake-super option only affects the side where the option is used. To affect the remote side of a remote-shell connection, use the
--remote-option (-M) option:

rsync -av -M--fake-super /src/ host:/dest/

For a local copy, this option affects both the source and the destination. If you wish a local copy to enable this option just for the
destination files, specify -M--fake-super. If you wish a local copy to enable this option just for the source files, combine --fake-super
with -M--super.

This option is overridden by both --super and --no-super.

See also the "fake super" setting in the daemon's rsyncd.conf file.

--sparse, -S
Try to handle sparse files efficiently so they take up less space on the destination. If combined with --inplace the file created might
not end up with sparse blocks with some combinations of kernel version and/or filesystem type. If --whole-file is in effect (e.g. for a
local copy) then it will always work because rsync truncates the file prior to writing out the updated version.

Note that versions of rsync older than 3.1.3 will reject the combination of --sparse and --inplace.

--preallocate
This tells the receiver to allocate each destination file to its eventual size before writing data to the file. Rsync will only use the
real filesystem-level preallocation support provided by Linux's fallocate(2) system call or Cygwin's posix_fallocate(3), not the slow
glibc implementation that writes a null byte into each block.

Without this option, larger files may not be entirely contiguous on the filesystem, but with this option rsync will probably copy more
slowly. If the destination is not an extent-supporting filesystem (such as ext4, xfs, NTFS, etc.), this option may have no positive efâАР
fect at all.

If combined with --sparse, the file will only have sparse blocks (as opposed to allocated sequences of null bytes) if the kernel version
and filesystem type support creating holes in the allocated data.

--dry-run, -n
This makes rsync perform a trial run that doesn't make any changes (and produces mostly the same output as a real run). It is most comâАР
monly used in combination with the --verbose, -v and/or --itemize-changes, -i options to see what an rsync command is going to do before
one actually runs it.

The output of --itemize-changes is supposed to be exactly the same on a dry run and a subsequent real run (barring intentional trickery
and system call failures); if it isn't, that's a bug. Other output should be mostly unchanged, but may differ in some areas. Notably, a
dry run does not send the actual data for file transfers, so --progress has no effect, the "bytes sent", "bytes received", "literal data",
and "matched data" statistics are too small, and the "speedup" value is equivalent to a run where no file transfers were needed.

--whole-file, -W
This option disables rsync's delta-transfer algorithm, which causes all transferred files to be sent whole. The transfer may be faster if
this option is used when the bandwidth between the source and destination machines is higher than the bandwidth to disk (especially when
the "disk" is actually a networked filesystem). This is the default when both the source and destination are specified as local paths,
but only if no batch-writing option is in effect.

--checksum-choice=STR, --cc=STR
This option overrides the checksum algorithms. If one algorithm name is specified, it is used for both the transfer checksums and (assumâАР
ing --checksum is specified) the pre-transfer checksums. If two comma-separated names are supplied, the first name affects the transfer
checksums, and the second name affects the pre-transfer checksums (-c).

The checksum options that you may be able to use are:

o auto (the default automatic choice)

o xxh128

o xxh3

o xxh64 (aka xxhash)

o md5

o md4

o none

Run rsync --version to see the default checksum list compiled into your version (which may differ from the list above).

If "none" is specified for the first (or only) name, the --whole-file option is forced on and no checksum verification is performed on the
transferred data. If "none" is specified for the second (or only) name, the --checksum option cannot be used.

The "auto" option is the default, where rsync bases its algorithm choice on a negotiation between the client and the server as follows:

When both sides of the transfer are at least 3.2.0, rsync chooses the first algorithm in the client's list of choices that is also in the
server's list of choices. If no common checksum choice is found, rsync exits with an error. If the remote rsync is too old to support
checksum negotiation, a value is chosen based on the protocol version (which chooses between MD5 and various flavors of MD4 based on proâАР
tocol age).

The default order can be customized by setting the environment variable RSYNC_CHECKSUM_LIST to a space-separated list of acceptable checkâАР
sum names. If the string contains a "&" character, it is separated into the "client string & server string", otherwise the same string
applies to both. If the string (or string portion) contains no non-whitespace characters, the default checksum list is used. This method
does not allow you to specify the transfer checksum separately from the pre-transfer checksum, and it discards "auto" and all unknown
checksum names. A list with only invalid names results in a failed negotiation.

The use of the --checksum-choice option overrides this environment list.

--one-file-system, -x
This tells rsync to avoid crossing a filesystem boundary when recursing. This does not limit the user's ability to specify items to copy
from multiple filesystems, just rsync's recursion through the hierarchy of each directory that the user specified, and also the analogous
recursion on the receiving side during deletion. Also keep in mind that rsync treats a "bind" mount to the same device as being on the
same filesystem.

If this option is repeated, rsync omits all mount-point directories from the copy. Otherwise, it includes an empty directory at each
mount-point it encounters (using the attributes of the mounted directory because those of the underlying mount-point directory are inacâАР
cessible).

If rsync has been told to collapse symlinks (via --copy-links or --copy-unsafe-links), a symlink to a directory on another device is
treated like a mount-point. Symlinks to non-directories are unaffected by this option.

--existing, --ignore-non-existing
This tells rsync to skip creating files (including directories) that do not exist yet on the destination. If this option is combined with
the --ignore-existing option, no files will be updated (which can be useful if all you want to do is delete extraneous files).

--ignore-existing
This tells rsync to skip updating files that already exist on the destination (this does not ignore existing directories, or nothing would
get done). See also --existing.

This option can be useful for those doing backups using the --link-dest option when they need to continue a backup run that got interâАР
rupted. Since a --link-dest run is copied into a new directory hierarchy (when it is used properly), using --ignore-existing will ensure
that the already-handled files don't get tweaked (which avoids a change in permissions on the hard-linked files). This does mean that
this option is only looking at the existing files in the destination hierarchy itself.

--remove-source-files
This tells rsync to remove from the sending side the files (meaning non-directories) that are a part of the transfer and have been sucâАР
cessfully duplicated on the receiving side.

Note that you should only use this option on source files that are quiescent. If you are using this to move files that show up in a parâАР
ticular directory over to another host, make sure that the finished files get renamed into the source directory, not directly written into
it, so that rsync can't possibly transfer a file that is not yet fully written. If you can't first write the files into a different diâАР
rectory, you should use a naming idiom that lets rsync avoid transferring files that are not yet finished (e.g. name the file "foo.new"
when it is written, rename it to "foo" when it is done, and then use the option --exclude='*.new' for the rsync transfer).

Starting with 3.1.0, rsync will skip the sender-side removal (and output an error) if the file's size or modify time has not stayed unâАР
changed.

--delete
This tells rsync to delete extraneous files from the receiving side (ones that aren't on the sending side), but only for the directories
that are being synchronized. You must have asked rsync to send the whole directory (e.g. "dir" or "dir/") without using a wildcard for
the directory's contents (e.g. "dir/*") since the wildcard is expanded by the shell and rsync thus gets a request to transfer individual
files, not the files' parent directory. Files that are excluded from the transfer are also excluded from being deleted unless you use the
--delete-excluded option or mark the rules as only matching on the sending side (see the include/exclude modifiers in the FILTER RULES
section).

Prior to rsync 2.6.7, this option would have no effect unless --recursive was enabled. Beginning with 2.6.7, deletions will also occur
when --dirs (-d) is enabled, but only for directories whose contents are being copied.

This option can be dangerous if used incorrectly! It is a very good idea to first try a run using the --dry-run option (-n) to see what
files are going to be deleted.

If the sending side detects any I/O errors, then the deletion of any files at the destination will be automatically disabled. This is to
prevent temporary filesystem failures (such as NFS errors) on the sending side from causing a massive deletion of files on the destinaâАР
tion. You can override this with the --ignore-errors option.

The --delete option may be combined with one of the --delete-WHEN options without conflict, as well as --delete-excluded. However, if
none of the --delete-WHEN options are specified, rsync will choose the --delete-during algorithm when talking to rsync 3.0.0 or newer, and
the --delete-before algorithm when talking to an older rsync. See also --delete-delay and --delete-after.

--delete-before
Request that the file-deletions on the receiving side be done before the transfer starts. See --delete (which is implied) for more deâАР
tails on file-deletion.

Deleting before the transfer is helpful if the filesystem is tight for space and removing extraneous files would help to make the transfer
possible. However, it does introduce a delay before the start of the transfer, and this delay might cause the transfer to timeout (if
--timeout was specified). It also forces rsync to use the old, non-incremental recursion algorithm that requires rsync to scan all the
files in the transfer into memory at once (see --recursive).

--delete-during, --del
Request that the file-deletions on the receiving side be done incrementally as the transfer happens. The per-directory delete scan is
done right before each directory is checked for updates, so it behaves like a more efficient --delete-before, including doing the deleâАР
tions prior to any per-directory filter files being updated. This option was first added in rsync version 2.6.4. See --delete (which is
implied) for more details on file-deletion.

--delete-delay
Request that the file-deletions on the receiving side be computed during the transfer (like --delete-during), and then removed after the
transfer completes. This is useful when combined with --delay-updates and/or --fuzzy, and is more efficient than using --delete-after
(but can behave differently, since --delete-after computes the deletions in a separate pass after all updates are done). If the number of
removed files overflows an internal buffer, a temporary file will be created on the receiving side to hold the names (it is removed while
open, so you shouldn't see it during the transfer). If the creation of the temporary file fails, rsync will try to fall back to using
--delete-after (which it cannot do if --recursive is doing an incremental scan). See --delete (which is implied) for more details on
file-deletion.

--delete-after
Request that the file-deletions on the receiving side be done after the transfer has completed. This is useful if you are sending new
per-directory merge files as a part of the transfer and you want their exclusions to take effect for the delete phase of the current
transfer. It also forces rsync to use the old, non-incremental recursion algorithm that requires rsync to scan all the files in the
transfer into memory at once (see --recursive). See --delete (which is implied) for more details on file-deletion.

--delete-excluded
In addition to deleting the files on the receiving side that are not on the sending side, this tells rsync to also delete any files on the
receiving side that are excluded (see --exclude). See the FILTER RULES section for a way to make individual exclusions behave this way on
the receiver, and for a way to protect files from --delete-excluded. See --delete (which is implied) for more details on file-deletion.

--ignore-missing-args
When rsync is first processing the explicitly requested source files (e.g. command-line arguments or --files-from entries), it is norâАР
mally an error if the file cannot be found. This option suppresses that error, and does not try to transfer the file. This does not afâАР
fect subsequent vanished-file errors if a file was initially found to be present and later is no longer there.

--delete-missing-args
This option takes the behavior of (the implied) --ignore-missing-args option a step farther: each missing arg will become a deletion reâАР
quest of the corresponding destination file on the receiving side (should it exist). If the destination file is a non-empty directory, it
will only be successfully deleted if --force or --delete are in effect. Other than that, this option is independent of any other type of
delete processing.

The missing source files are represented by special file-list entries which display as a "*missing" entry in the --list-only output.

--ignore-errors
Tells --delete to go ahead and delete files even when there are I/O errors.

--force
This option tells rsync to delete a non-empty directory when it is to be replaced by a non-directory. This is only relevant if deletions
are not active (see --delete for details).

Note for older rsync versions: --force used to still be required when using --delete-after, and it used to be non-functional unless the
--recursive option was also enabled.

--max-delete=NUM
This tells rsync not to delete more than NUM files or directories. If that limit is exceeded, all further deletions are skipped through
the end of the transfer. At the end, rsync outputs a warning (including a count of the skipped deletions) and exits with an error code of
25 (unless some more important error condition also occurred).

Beginning with version 3.0.0, you may specify --max-delete=0 to be warned about any extraneous files in the destination without removing
any of them. Older clients interpreted this as "unlimited", so if you don't know what version the client is, you can use the less obvious
--max-delete=-1 as a backward-compatible way to specify that no deletions be allowed (though really old versions didn't warn when the
limit was exceeded).

--max-size=SIZE
This tells rsync to avoid transferring any file that is larger than the specified SIZE. A numeric value can be suffixed with a string to
indicate the numeric units or left unqualified to specify bytes. Feel free to use a fractional value along with the units, such as --max-
size=1.5m.

The first letter of a units string can be B (bytes), K (kilo), M (mega), G (giga), T (tera), or P (peta). If the string is a single char
or has "ib" added to it (e.g. "G" or "GiB") then the units are multiples of 1024. If you use a two-letter suffix that ends with a "B"
(e.g. "kb") then you get units that are multiples of 1000. The string's letters can be any mix of upper and lower-case that you want to
use.

Finally, if the string ends with either "+1" or "-1", it is offset by one byte in the indicated direction. The largest possible value is
usually 8192P-1.

Examples: --max-size=1.5mb-1 is 1499999 bytes, and --max-size=2g+1 is 2147483649 bytes.

Note that rsync versions prior to 3.1.0 did not allow --max-size=0.

--min-size=SIZE
This tells rsync to avoid transferring any file that is smaller than the specified SIZE, which can help in not transferring small, junk
files. See the --max-size option for a description of SIZE and other information.

Note that rsync versions prior to 3.1.0 did not allow --min-size=0.

--max-alloc=SIZE
By default rsync limits an individual malloc/realloc to about 1GB in size. For most people this limit works just fine and prevents a proâАР
tocol error causing rsync to request massive amounts of memory. However, if you have many millions of files in a transfer, a large amount
of server memory, and you don't want to split up your transfer into multiple parts, you can increase the per-allocation limit to something
larger and rsync will consume more memory.

Keep in mind that this is not a limit on the total size of allocated memory. It is a sanity-check value for each individual allocation.

See the --max-size option for a description of how SIZE can be specified. The default suffix if none is given is bytes.

Beginning in 3.2.3, a value of 0 specifies no limit.

You can set a default value using the environment variable RSYNC_MAX_ALLOC using the same SIZE values as supported by this option. If the
remote rsync doesn't understand the --max-alloc option, you can override an environmental value by specifying --max-alloc=1g, which will
make rsync avoid sending the option to the remote side (because "1G" is the default).

--block-size=SIZE, -B
This forces the block size used in rsync's delta-transfer algorithm to a fixed value. It is normally selected based on the size of each
file being updated. See the technical report for details.

Beginning in 3.2.3 the SIZE can be specified with a suffix as detailed in the --max-size option. Older versions only accepted a byte
count.

--rsh=COMMAND, -e
This option allows you to choose an alternative remote shell program to use for communication between the local and remote copies of
rsync. Typically, rsync is configured to use ssh by default, but you may prefer to use rsh on a local network.

If this option is used with [user@]host::module/path, then the remote shell COMMAND will be used to run an rsync daemon on the remote
host, and all data will be transmitted through that remote shell connection, rather than through a direct socket connection to a running
rsync daemon on the remote host. See the section "USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION" above.

Beginning with rsync 3.2.0, the RSYNC_PORT environment variable will be set when a daemon connection is being made via a remote-shell conâАР
nection. It is set to 0 if the default daemon port is being assumed, or it is set to the value of the rsync port that was specified via
either the --port option or a non-empty port value in an rsync:// URL. This allows the script to discern if a non-default port is being
requested, allowing for things such as an SSL or stunnel helper script to connect to a default or alternate port.

Command-line arguments are permitted in COMMAND provided that COMMAND is presented to rsync as a single argument. You must use spaces
(not tabs or other whitespace) to separate the command and args from each other, and you can use single- and/or double-quotes to preserve
spaces in an argument (but not backslashes). Note that doubling a single-quote inside a single-quoted string gives you a single-quote;
likewise for double-quotes (though you need to pay attention to which quotes your shell is parsing and which quotes rsync is parsing).
Some examples:

-e 'ssh -p 2234'
-e 'ssh -o "ProxyCommand nohup ssh firewall nc -w1 %h %p"'

(Note that ssh users can alternately customize site-specific connect options in their .ssh/config file.)

You can also choose the remote shell program using the RSYNC_RSH environment variable, which accepts the same range of values as -e.

See also the --blocking-io option which is affected by this option.

--rsync-path=PROGRAM
Use this to specify what program is to be run on the remote machine to start-up rsync. Often used when rsync is not in the default reâАР
mote-shell's path (e.g. --rsync-path=/usr/local/bin/rsync). Note that PROGRAM is run with the help of a shell, so it can be any program,
script, or command sequence you'd care to run, so long as it does not corrupt the standard-in & standard-out that rsync is using to commuâАР
nicate.

One tricky example is to set a different default directory on the remote machine for use with the --relative option. For instance:

rsync -avR --rsync-path="cd /a/b && rsync" host:c/d /e/

--remote-option=OPTION, -M
This option is used for more advanced situations where you want certain effects to be limited to one side of the transfer only. For inâАР
stance, if you want to pass --log-file=FILE and --fake-super to the remote system, specify it like this:

rsync -av -M --log-file=foo -M--fake-super src/ dest/

If you want to have an option affect only the local side of a transfer when it normally affects both sides, send its negation to the reâАР
mote side. Like this:

rsync -av -x -M--no-x src/ dest/

Be cautious using this, as it is possible to toggle an option that will cause rsync to have a different idea about what data to expect
next over the socket, and that will make it fail in a cryptic fashion.

Note that it is best to use a separate --remote-option for each option you want to pass. This makes your usage compatible with the --proâАР
tect-args option. If that option is off, any spaces in your remote options will be split by the remote shell unless you take steps to
protect them.

When performing a local transfer, the "local" side is the sender and the "remote" side is the receiver.

Note some versions of the popt option-parsing library have a bug in them that prevents you from using an adjacent arg with an equal in it
next to a short option letter (e.g. -M--log-file=/tmp/foo). If this bug affects your version of popt, you can use the version of popt
that is included with rsync.

--cvs-exclude, -C
This is a useful shorthand for excluding a broad range of files that you often don't want to transfer between systems. It uses a similar
algorithm to CVS to determine if a file should be ignored.

The exclude list is initialized to exclude the following items (these initial items are marked as perishable -- see the FILTER RULES secâАР
tion):

RCS SCCS CVS CVS.adm RCSLOG cvslog.* tags TAGS .make.state .nse_depinfo ~ . , _$* *$ *.old *.bak *.BAK *.orig .rej .del- *.a
*.olb *.o *.obj *.so *.exe *.Z *.elc *.ln core .svn/ .git/ .hg/ .bzr/

then, files listed in a $HOME/.cvsignore are added to the list and any files listed in the CVSIGNORE environment variable (all cvsignore
names are delimited by whitespace).

Finally, any file is ignored if it is in the same directory as a .cvsignore file and matches one of the patterns listed therein. Unlike
rsync's filter/exclude files, these patterns are split on whitespace. See the cvs(1) manual for more information.

If you're combining -C with your own --filter rules, you should note that these CVS excludes are appended at the end of your own rules,
regardless of where the -C was placed on the command-line. This makes them a lower priority than any rules you specified explicitly. If
you want to control where these CVS excludes get inserted into your filter rules, you should omit the -C as a command-line option and use
a combination of --filter=:C and --filter=-C (either on your command-line or by putting the ":C" and "-C" rules into a filter file with
your other rules). The first option turns on the per-directory scanning for the .cvsignore file. The second option does a one-time imâАР
port of the CVS excludes mentioned above.

--filter=RULE, -f
This option allows you to add rules to selectively exclude certain files from the list of files to be transferred. This is most useful in
combination with a recursive transfer.

You may use as many --filter options on the command line as you like to build up the list of files to exclude. If the filter contains
whitespace, be sure to quote it so that the shell gives the rule to rsync as a single argument. The text below also mentions that you can
use an underscore to replace the space that separates a rule from its arg.

See the FILTER RULES section for detailed information on this option.

-F The -F option is a shorthand for adding two --filter rules to your command. The first time it is used is a shorthand for this rule:

--filter='dir-merge /.rsync-filter'

This tells rsync to look for per-directory .rsync-filter files that have been sprinkled through the hierarchy and use their rules to filâАР
ter the files in the transfer. If -F is repeated, it is a shorthand for this rule:

--filter='exclude .rsync-filter'

This filters out the .rsync-filter files themselves from the transfer.

See the FILTER RULES section for detailed information on how these options work.

--exclude=PATTERN
This option is a simplified form of the --filter option that defaults to an exclude rule and does not allow the full rule-parsing syntax
of normal filter rules.

See the FILTER RULES section for detailed information on this option.

--exclude-from=FILE
This option is related to the --exclude option, but it specifies a FILE that contains exclude patterns (one per line). Blank lines in the
file are ignored, as are whole-line comments that start with ';' or '#' (filename rules that contain those characters are unaffected).

If FILE is '-', the list will be read from standard input.

--include=PATTERN
This option is a simplified form of the --filter option that defaults to an include rule and does not allow the full rule-parsing syntax
of normal filter rules.

See the FILTER RULES section for detailed information on this option.

--include-from=FILE
This option is related to the --include option, but it specifies a FILE that contains include patterns (one per line). Blank lines in the
file are ignored, as are whole-line comments that start with ';' or '#' (filename rules that contain those characters are unaffected).

If FILE is '-', the list will be read from standard input.

--files-from=FILE
Using this option allows you to specify the exact list of files to transfer (as read from the specified FILE or '-' for standard input).
It also tweaks the default behavior of rsync to make transferring just the specified files and directories easier:

o The --relative (-R) option is implied, which preserves the path information that is specified for each item in the file (use --no-
relative or --no-R if you want to turn that off).

o The --dirs (-d) option is implied, which will create directories specified in the list on the destination rather than noisily skipâАР
ping them (use --no-dirs or --no-d if you want to turn that off).

o The --archive (-a) option's behavior does not imply --recursive (-r), so specify it explicitly, if you want it.

o These side-effects change the default state of rsync, so the position of the --files-from option on the command-line has no bearing
on how other options are parsed (e.g. -a works the same before or after --files-from, as does --no-R and all other options).

The filenames that are read from the FILE are all relative to the source dir -- any leading slashes are removed and no ".." references are
allowed to go higher than the source dir. For example, take this command:

rsync -a --files-from=/tmp/foo /usr remote:/backup

If /tmp/foo contains the string "bin" (or even "/bin"), the /usr/bin directory will be created as /backup/bin on the remote host. If it
contains "bin/" (note the trailing slash), the immediate contents of the directory would also be sent (without needing to be explicitly
mentioned in the file -- this began in version 2.6.4). In both cases, if the -r option was enabled, that dir's entire hierarchy would
also be transferred (keep in mind that -r needs to be specified explicitly with --files-from, since it is not implied by -a). Also note
that the effect of the (enabled by default) --relative option is to duplicate only the path info that is read from the file -- it does not
force the duplication of the source-spec path (/usr in this case).

In addition, the --files-from file can be read from the remote host instead of the local host if you specify a "host:" in front of the
file (the host must match one end of the transfer). As a short-cut, you can specify just a prefix of ":" to mean "use the remote end of
the transfer". For example:

rsync -a --files-from=:/path/file-list src:/ /tmp/copy

This would copy all the files specified in the /path/file-list file that was located on the remote "src" host.

If the --iconv and --protect-args options are specified and the --files-from filenames are being sent from one host to another, the fileâАР
names will be translated from the sending host's charset to the receiving host's charset.

NOTE: sorting the list of files in the --files-from input helps rsync to be more efficient, as it will avoid re-visiting the path elements
that are shared between adjacent entries. If the input is not sorted, some path elements (implied directories) may end up being scanned
multiple times, and rsync will eventually unduplicate them after they get turned into file-list elements.

--from0, -0
This tells rsync that the rules/filenames it reads from a file are terminated by a null ('\0') character, not a NL, CR, or CR+LF. This
affects --exclude-from, --include-from, --files-from, and any merged files specified in a --filter rule. It does not affect --cvs-exclude
(since all names read from a .cvsignore file are split on whitespace).

--protect-args, -s
This option sends all filenames and most options to the remote rsync without allowing the remote shell to interpret them. This means that
spaces are not split in names, and any non-wildcard special characters are not translated (such as ~, $, ;, &, etc.). Wildcards are exâАР
panded on the remote host by rsync (instead of the shell doing it).

If you use this option with --iconv, the args related to the remote side will also be translated from the local to the remote character-
set. The translation happens before wild-cards are expanded. See also the --files-from option.

You may also control this option via the RSYNC_PROTECT_ARGS environment variable. If this variable has a non-zero value, this option will
be enabled by default, otherwise it will be disabled by default. Either state is overridden by a manually specified positive or negative
version of this option (note that --no-s and --no-protect-args are the negative versions). Since this option was first introduced in
3.0.0, you'll need to make sure it's disabled if you ever need to interact with a remote rsync that is older than that.

Rsync can also be configured (at build time) to have this option enabled by default (with is overridden by both the environment and the
command-line). Run rsync --version to check if this is the case, as it will display "default protect-args" or "optional protect-args" deâАР
pending on how it was compiled.

This option will eventually become a new default setting at some as-yet-undetermined point in the future.

--copy-as=USER[:GROUP]
This option instructs rsync to use the USER and (if specified after a colon) the GROUP for the copy operations. This only works if the
user that is running rsync has the ability to change users. If the group is not specified then the user's default groups are used.

This option can help to reduce the risk of an rsync being run as root into or out of a directory that might have live changes happening to
it and you want to make sure that root-level read or write actions of system files are not possible. While you could alternatively run
all of rsync as the specified user, sometimes you need the root-level host-access credentials to be used, so this allows rsync to drop
root for the copying part of the operation after the remote-shell or daemon connection is established.

The option only affects one side of the transfer unless the transfer is local, in which case it affects both sides. Use the --remote-opâАР
tion to affect the remote side, such as -M--copy-as=joe. For a local transfer, the lsh (or lsh.sh) support file provides a local-shell
helper script that can be used to allow a "localhost:" or "lh:" host-spec to be specified without needing to setup any remote shells, alâАР
lowing you to specify remote options that affect the side of the transfer that is using the host-spec (and using hostname "lh" avoids the
overriding of the remote directory to the user's home dir).

For example, the following rsync writes the local files as user "joe":

sudo rsync -aiv --copy-as=joe host1:backups/joe/ /home/joe/

This makes all files owned by user "joe", limits the groups to those that are available to that user, and makes it impossible for the joe
user to do a timed exploit of the path to induce a change to a file that the joe user has no permissions to change.

The following command does a local copy into the "dest/" dir as user "joe" (assuming you've installed support/lsh into a dir on your
$PATH):

sudo rsync -aive lsh -M--copy-as=joe src/ lh:dest/

--temp-dir=DIR, -T
This option instructs rsync to use DIR as a scratch directory when creating temporary copies of the files transferred on the receiving
side. The default behavior is to create each temporary file in the same directory as the associated destination file. Beginning with
rsync 3.1.1, the temp-file names inside the specified DIR will not be prefixed with an extra dot (though they will still have a random
suffix added).

This option is most often used when the receiving disk partition does not have enough free space to hold a copy of the largest file in the
transfer. In this case (i.e. when the scratch directory is on a different disk partition), rsync will not be able to rename each received
temporary file over the top of the associated destination file, but instead must copy it into place. Rsync does this by copying the file
over the top of the destination file, which means that the destination file will contain truncated data during this copy. If this were
not done this way (even if the destination file were first removed, the data locally copied to a temporary file in the destination direcâАР
tory, and then renamed into place) it would be possible for the old file to continue taking up disk space (if someone had it open), and
thus there might not be enough room to fit the new version on the disk at the same time.

If you are using this option for reasons other than a shortage of disk space, you may wish to combine it with the --delay-updates option,
which will ensure that all copied files get put into subdirectories in the destination hierarchy, awaiting the end of the transfer. If
you don't have enough room to duplicate all the arriving files on the destination partition, another way to tell rsync that you aren't
overly concerned about disk space is to use the --partial-dir option with a relative path; because this tells rsync that it is OK to stash
off a copy of a single file in a subdir in the destination hierarchy, rsync will use the partial-dir as a staging area to bring over the
copied file, and then rename it into place from there. (Specifying a --partial-dir with an absolute path does not have this side-effect.)

--fuzzy, -y
This option tells rsync that it should look for a basis file for any destination file that is missing. The current algorithm looks in the
same directory as the destination file for either a file that has an identical size and modified-time, or a similarly-named file. If
found, rsync uses the fuzzy basis file to try to speed up the transfer.

If the option is repeated, the fuzzy scan will also be done in any matching alternate destination directories that are specified via
--compare-dest, --copy-dest, or --link-dest.

Note that the use of the --delete option might get rid of any potential fuzzy-match files, so either use --delete-after or specify some
filename exclusions if you need to prevent this.

--compare-dest=DIR
This option instructs rsync to use DIR on the destination machine as an additional hierarchy to compare destination files against doing
transfers (if the files are missing in the destination directory). If a file is found in DIR that is identical to the sender's file, the
file will NOT be transferred to the destination directory. This is useful for creating a sparse backup of just files that have changed
from an earlier backup. This option is typically used to copy into an empty (or newly created) directory.

Beginning in version 2.6.4, multiple --compare-dest directories may be provided, which will cause rsync to search the list in the order
specified for an exact match. If a match is found that differs only in attributes, a local copy is made and the attributes updated. If a
match is not found, a basis file from one of the DIRs will be selected to try to speed up the transfer.

If DIR is a relative path, it is relative to the destination directory. See also --copy-dest and --link-dest.

NOTE: beginning with version 3.1.0, rsync will remove a file from a non-empty destination hierarchy if an exact match is found in one of
the compare-dest hierarchies (making the end result more closely match a fresh copy).

--copy-dest=DIR
This option behaves like --compare-dest, but rsync will also copy unchanged files found in DIR to the destination directory using a local
copy. This is useful for doing transfers to a new destination while leaving existing files intact, and then doing a flash-cutover when
all files have been successfully transferred.

Multiple --copy-dest directories may be provided, which will cause rsync to search the list in the order specified for an unchanged file.
If a match is not found, a basis file from one of the DIRs will be selected to try to speed up the transfer.

If DIR is a relative path, it is relative to the destination directory. See also --compare-dest and --link-dest.

--link-dest=DIR
This option behaves like --copy-dest, but unchanged files are hard linked from DIR to the destination directory. The files must be idenâАР
tical in all preserved attributes (e.g. permissions, possibly ownership) in order for the files to be linked together. An example:

rsync -av --link-dest=$PWD/prior_dir host:src_dir/ new_dir/

If file's aren't linking, double-check their attributes. Also check if some attributes are getting forced outside of rsync's control,
such a mount option that squishes root to a single user, or mounts a removable drive with generic ownership (such as OS X's "Ignore ownerâАР
ship on this volume" option).

Beginning in version 2.6.4, multiple --link-dest directories may be provided, which will cause rsync to search the list in the order specâАР
ified for an exact match (there is a limit of 20 such directories). If a match is found that differs only in attributes, a local copy is
made and the attributes updated. If a match is not found, a basis file from one of the DIRs will be selected to try to speed up the
transfer.

This option works best when copying into an empty destination hierarchy, as existing files may get their attributes tweaked, and that can
affect alternate destination files via hard-links. Also, itemizing of changes can get a bit muddled. Note that prior to version 3.1.0,
an alternate-directory exact match would never be found (nor linked into the destination) when a destination file already exists.

Note that if you combine this option with --ignore-times, rsync will not link any files together because it only links identical files toâАР
gether as a substitute for transferring the file, never as an additional check after the file is updated.

If DIR is a relative path, it is relative to the destination directory. See also --compare-dest and --copy-dest.

Note that rsync versions prior to 2.6.1 had a bug that could prevent --link-dest from working properly for a non-super-user when -o was
specified (or implied by -a). You can work-around this bug by avoiding the -o option when sending to an old rsync.

--compress, -z
With this option, rsync compresses the file data as it is sent to the destination machine, which reduces the amount of data being transâАР
mitted -- something that is useful over a slow connection.

Rsync supports multiple compression methods and will choose one for you unless you force the choice using the --compress-choice (--zc) opâАР
tion.

Run rsync --version to see the default compress list compiled into your version.

When both sides of the transfer are at least 3.2.0, rsync chooses the first algorithm in the client's list of choices that is also in the
server's list of choices. If no common compress choice is found, rsync exits with an error. If the remote rsync is too old to support
checksum negotiation, its list is assumed to be "zlib".

The default order can be customized by setting the environment variable RSYNC_COMPRESS_LIST to a space-separated list of acceptable comâАР
pression names. If the string contains a "&" character, it is separated into the "client string & server string", otherwise the same
string applies to both. If the string (or string portion) contains no non-whitespace characters, the default compress list is used. Any
unknown compression names are discarded from the list, but a list with only invalid names results in a failed negotiation.

There are some older rsync versions that were configured to reject a -z option and require the use of -zz because their compression liâАР
brary was not compatible with the default zlib compression method. You can usually ignore this weirdness unless the rsync server comâАР
plains and tells you to specify -zz.

See also the --skip-compress option for the default list of file suffixes that will be transferred with no (or minimal) compression.

--compress-choice=STR, --zc=STR
This option can be used to override the automatic negotiation of the compression algorithm that occurs when --compress is used. The opâАР
tion implies --compress unless "none" was specified, which instead implies --no-compress.

The compression options that you may be able to use are:

o zstd

o lz4

o zlibx

o zlib

o none

Run rsync --version to see the default compress list compiled into your version (which may differ from the list above).

Note that if you see an error about an option named --old-compress or --new-compress, this is rsync trying to send the --compress-
choice=zlib or --compress-choice=zlibx option in a backward-compatible manner that more rsync versions understand. This error indicates
that the older rsync version on the server will not allow you to force the compression type.

Note that the "zlibx" compression algorithm is just the "zlib" algorithm with matched data excluded from the compression stream (to try to
make it more compatible with an external zlib implementation).

--compress-level=NUM, --zl=NUM
Explicitly set the compression level to use (see --compress, -z) instead of letting it default. The --compress option is implied as long
as the level chosen is not a "don't compress" level for the compression algorithm that is in effect (e.g. zlib compression treats level 0
as "off").

The level values vary depending on the checksum in effect. Because rsync will negotiate a checksum choice by default (when the remote
rsync is new enough), it can be good to combine this option with a --compress-choice (--zc) option unless you're sure of the choice in efâАР
fect. For example:

rsync -aiv --zc=zstd --zl=22 host:src/ dest/

For zlib & zlibx compression the valid values are from 1 to 9 with 6 being the default. Specifying 0 turns compression off, and specifyâАР
ing -1 chooses the default of 6.

For zstd compression the valid values are from -131072 to 22 with 3 being the default. Specifying 0 chooses the default of 3.

For lz4 compression there are no levels, so the value is always 0.

If you specify a too-large or too-small value, the number is silently limited to a valid value. This allows you to specify something like
--zl=999999999 and be assured that you'll end up with the maximum compression level no matter what algorithm was chosen.

If you want to know the compression level that is in effect, specify --debug=nstr to see the "negotiated string" results. This will reâАР
port something like "Client compress: zstd (level 3)" (along with the checksum choice in effect).

--skip-compress=LIST
Override the list of file suffixes that will be compressed as little as possible. Rsync sets the compression level on a per-file basis
based on the file's suffix. If the compression algorithm has an "off" level (such as zlib/zlibx) then no compression occurs for those
files. Other algorithms that support changing the streaming level on-the-fly will have the level minimized to reduces the CPU usage as
much as possible for a matching file. At this time, only zlib & zlibx compression support this changing of levels on a per-file basis.

The LIST should be one or more file suffixes (without the dot) separated by slashes (/). You may specify an empty string to indicate that
no files should be skipped.

Simple character-class matching is supported: each must consist of a list of letters inside the square brackets (e.g. no special classes,
such as "[:alpha:]", are supported, and '-' has no special meaning).

The characters asterisk (*) and question-mark (?) have no special meaning.

Here's an example that specifies 6 suffixes to skip (since 1 of the 5 rules matches 2 suffixes):

--skip-compress=gz/jpg/mp[34]/7z/bz2

The default file suffixes in the skip-compress list in this version of rsync are:

3g2 3gp 7z aac ace apk avi bz2 deb dmg ear f4v flac flv gpg gz iso jar jpeg jpg lrz lz lz4 lzma lzo m1a m1v m2a m2ts m2v m4a m4b m4p
m4r m4v mka mkv mov mp1 mp2 mp3 mp4 mpa mpeg mpg mpv mts odb odf odg odi odm odp ods odt oga ogg ogm ogv ogx opus otg oth otp ots ott
oxt png qt rar rpm rz rzip spx squashfs sxc sxd sxg sxm sxw sz tbz tbz2 tgz tlz ts txz tzo vob war webm webp xz z zip zst

This list will be replaced by your --skip-compress list in all but one situation: a copy from a daemon rsync will add your skipped sufâАР
fixes to its list of non-compressing files (and its list may be configured to a different default).

--numeric-ids
With this option rsync will transfer numeric group and user IDs rather than using user and group names and mapping them at both ends.

By default rsync will use the username and groupname to determine what ownership to give files. The special uid 0 and the special group 0
are never mapped via user/group names even if the --numeric-ids option is not specified.

If a user or group has no name on the source system or it has no match on the destination system, then the numeric ID from the source sysâАР
tem is used instead. See also the comments on the "use chroot" setting in the rsyncd.conf manpage for information on how the chroot setâАР
ting affects rsync's ability to look up the names of the users and groups and what you can do about it.

--usermap=STRING, --groupmap=STRING
These options allow you to specify users and groups that should be mapped to other values by the receiving side. The STRING is one or
more FROM:TO pairs of values separated by commas. Any matching FROM value from the sender is replaced with a TO value from the receiver.
You may specify usernames or user IDs for the FROM and TO values, and the FROM value may also be a wild-card string, which will be matched
against the sender's names (wild-cards do NOT match against ID numbers, though see below for why a '*' matches everything). You may inâАР
stead specify a range of ID numbers via an inclusive range: LOW-HIGH. For example:

--usermap=0-99:nobody,wayne:admin,*:normal --groupmap=usr:1,1:usr

The first match in the list is the one that is used. You should specify all your user mappings using a single --usermap option, and/or
all your group mappings using a single --groupmap option.

Note that the sender's name for the 0 user and group are not transmitted to the receiver, so you should either match these values using a
0, or use the names in effect on the receiving side (typically "root"). All other FROM names match those in use on the sending side. All
TO names match those in use on the receiving side.

Any IDs that do not have a name on the sending side are treated as having an empty name for the purpose of matching. This allows them to
be matched via a "*" or using an empty name. For instance:

--usermap=:nobody --groupmap=*:nobody

When the --numeric-ids option is used, the sender does not send any names, so all the IDs are treated as having an empty name. This means
that you will need to specify numeric FROM values if you want to map these nameless IDs to different values.

For the --usermap option to have any effect, the -o (--owner) option must be used (or implied), and the receiver will need to be running
as a super-user (see also the --fake-super option). For the --groupmap option to have any effect, the -g (--group) option must be used
(or implied), and the receiver will need to have permissions to set that group.

If your shell complains about the wildcards, use --protect-args (-s).

--chown=USER:GROUP
This option forces all files to be owned by USER with group GROUP. This is a simpler interface than using --usermap and --groupmap diâАР
rectly, but it is implemented using those options internally, so you cannot mix them. If either the USER or GROUP is empty, no mapping
for the omitted user/group will occur. If GROUP is empty, the trailing colon may be omitted, but if USER is empty, a leading colon must
be supplied.

If you specify "--chown=foo:bar", this is exactly the same as specifying "--usermap=:foo --groupmap=:bar", only easier. If your shell
complains about the wildcards, use --protect-args (-s).

--timeout=SECONDS
This option allows you to set a maximum I/O timeout in seconds. If no data is transferred for the specified time then rsync will exit.
The default is 0, which means no timeout.

--contimeout=SECONDS
This option allows you to set the amount of time that rsync will wait for its connection to an rsync daemon to succeed. If the timeout is
reached, rsync exits with an error.

--address=ADDRESS
By default rsync will bind to the wildcard address when connecting to an rsync daemon. The --address option allows you to specify a speâАР
cific IP address (or hostname) to bind to. See also this option in the --daemon mode section.

--port=PORT
This specifies an alternate TCP port number to use rather than the default of 873. This is only needed if you are using the double-colon
(::) syntax to connect with an rsync daemon (since the URL syntax has a way to specify the port as a part of the URL). See also this opâАР
tion in the --daemon mode section.

--sockopts=OPTIONS
This option can provide endless fun for people who like to tune their systems to the utmost degree. You can set all sorts of socket opâАР
tions which may make transfers faster (or slower!). Read the man page for the setsockopt() system call for details on some of the options
you may be able to set. By default no special socket options are set. This only affects direct socket connections to a remote rsync daeâАР
mon.

This option also exists in the --daemon mode section.

--blocking-io
This tells rsync to use blocking I/O when launching a remote shell transport. If the remote shell is either rsh or remsh, rsync defaults
to using blocking I/O, otherwise it defaults to using non-blocking I/O. (Note that ssh prefers non-blocking I/O.)

--outbuf=MODE
This sets the output buffering mode. The mode can be None (aka Unbuffered), Line, or Block (aka Full). You may specify as little as a
single letter for the mode, and use upper or lower case.

The main use of this option is to change Full buffering to Line buffering when rsync's output is going to a file or pipe.

--itemize-changes, -i
Requests a simple itemized list of the changes that are being made to each file, including attribute changes. This is exactly the same as
specifying --out-format='%i %n%L'. If you repeat the option, unchanged files will also be output, but only if the receiving rsync is at
least version 2.6.7 (you can use -vv with older versions of rsync, but that also turns on the output of other verbose messages).

The "%i" escape has a cryptic output that is 11 letters long. The general format is like the string YXcstpoguax, where Y is replaced by
the type of update being done, X is replaced by the file-type, and the other letters represent attributes that may be output if they are
being modified.

The update types that replace the Y are as follows:

o A < means that a file is being transferred to the remote host (sent).

o A > means that a file is being transferred to the local host (received).

o A c means that a local change/creation is occurring for the item (such as the creation of a directory or the changing of a symlink,
etc.).

o A h means that the item is a hard link to another item (requires --hard-links).

o A . means that the item is not being updated (though it might have attributes that are being modified).

o A * means that the rest of the itemized-output area contains a message (e.g. "deleting").

The file-types that replace the X are: f for a file, a d for a directory, an L for a symlink, a D for a device, and a S for a special file
(e.g. named sockets and fifos).

The other letters in the string indicate if some attributes of the file have changed, as follows:

o "." - the attribute is unchanged.

o "+" - the file is newly created.

o " " - all the attributes are unchanged (all dots turn to spaces).

o "?" - the change is unknown (when the remote rsync is old).

o A letter indicates an attribute is being updated.

The attribute that is associated with each letter is as follows:

o A c means either that a regular file has a different checksum (requires --checksum) or that a symlink, device, or special file has
a changed value. Note that if you are sending files to an rsync prior to 3.0.1, this change flag will be present only for checkâАР
sum-differing regular files.

o A s means the size of a regular file is different and will be updated by the file transfer.

o A t means the modification time is different and is being updated to the sender's value (requires --times). An alternate value of
T means that the modification time will be set to the transfer time, which happens when a file/symlink/device is updated without
--times and when a symlink is changed and the receiver can't set its time. (Note: when using an rsync 3.0.0 client, you might see
the s flag combined with t instead of the proper T flag for this time-setting failure.)

o A p means the permissions are different and are being updated to the sender's value (requires --perms).

o An o means the owner is different and is being updated to the sender's value (requires --owner and super-user privileges).

o A g means the group is different and is being updated to the sender's value (requires --group and the authority to set the group).

o A u|n|b indicates the following information: u means the access (use) time is different and is being updated to the sender's value
(requires --atimes); n means the create time (newness) is different and is being updated to the sender's value (requires --crâАР
times); b means that both the access and create times are being updated.

o The a means that the ACL information is being changed.

o The x means that the extended attribute information is being changed.

One other output is possible: when deleting files, the "%i" will output the string "*deleting" for each item that is being removed (assumâАР
ing that you are talking to a recent enough rsync that it logs deletions instead of outputting them as a verbose message).

--out-format=FORMAT
This allows you to specify exactly what the rsync client outputs to the user on a per-update basis. The format is a text string containâАР
ing embedded single-character escape sequences prefixed with a percent (%) character. A default format of "%n%L" is assumed if either
--info=name or -v is specified (this tells you just the name of the file and, if the item is a link, where it points). For a full list of
the possible escape characters, see the "log format" setting in the rsyncd.conf manpage.

Specifying the --out-format option implies the --info=name option, which will mention each file, dir, etc. that gets updated in a signifiâАР
cant way (a transferred file, a recreated symlink/device, or a touched directory). In addition, if the itemize-changes escape (%i) is inâАР
cluded in the string (e.g. if the --itemize-changes option was used), the logging of names increases to mention any item that is changed
in any way (as long as the receiving side is at least 2.6.4). See the --itemize-changes option for a description of the output of "%i".

Rsync will output the out-format string prior to a file's transfer unless one of the transfer-statistic escapes is requested, in which
case the logging is done at the end of the file's transfer. When this late logging is in effect and --progress is also specified, rsync
will also output the name of the file being transferred prior to its progress information (followed, of course, by the out-format output).

--log-file=FILE
This option causes rsync to log what it is doing to a file. This is similar to the logging that a daemon does, but can be requested for
the client side and/or the server side of a non-daemon transfer. If specified as a client option, transfer logging will be enabled with a
default format of "%i %n%L". See the --log-file-format option if you wish to override this.

Here's a example command that requests the remote side to log what is happening:

rsync -av --remote-option=--log-file=/tmp/rlog src/ dest/

This is very useful if you need to debug why a connection is closing unexpectedly.

--log-file-format=FORMAT
This allows you to specify exactly what per-update logging is put into the file specified by the --log-file option (which must also be
specified for this option to have any effect). If you specify an empty string, updated files will not be mentioned in the log file. For
a list of the possible escape characters, see the "log format" setting in the rsyncd.conf manpage.

The default FORMAT used if --log-file is specified and this option is not is '%i %n%L'.

--stats
This tells rsync to print a verbose set of statistics on the file transfer, allowing you to tell how effective rsync's delta-transfer alâАР
gorithm is for your data. This option is equivalent to --info=stats2 if combined with 0 or 1 -v options, or --info=stats3 if combined
with 2 or more -v options.

The current statistics are as follows:

o Number of files is the count of all "files" (in the generic sense), which includes directories, symlinks, etc. The total count
will be followed by a list of counts by filetype (if the total is non-zero). For example: "(reg: 5, dir: 3, link: 2, dev: 1, speâАР
cial: 1)" lists the totals for regular files, directories, symlinks, devices, and special files. If any of value is 0, it is comâАР
pletely omitted from the list.

o Number of created files is the count of how many "files" (generic sense) were created (as opposed to updated). The total count
will be followed by a list of counts by filetype (if the total is non-zero).

o Number of deleted files is the count of how many "files" (generic sense) were deleted. The total count will be followed by a list
of counts by filetype (if the total is non-zero). Note that this line is only output if deletions are in effect, and only if proâАР
tocol 31 is being used (the default for rsync 3.1.x).

o Number of regular files transferred is the count of normal files that were updated via rsync's delta-transfer algorithm, which does
not include dirs, symlinks, etc. Note that rsync 3.1.0 added the word "regular" into this heading.

o Total file size is the total sum of all file sizes in the transfer. This does not count any size for directories or special files,
but does include the size of symlinks.

o Total transferred file size is the total sum of all files sizes for just the transferred files.

o Literal data is how much unmatched file-update data we had to send to the receiver for it to recreate the updated files.

o Matched data is how much data the receiver got locally when recreating the updated files.

o File list size is how big the file-list data was when the sender sent it to the receiver. This is smaller than the in-memory size
for the file list due to some compressing of duplicated data when rsync sends the list.

o File list generation time is the number of seconds that the sender spent creating the file list. This requires a modern rsync on
the sending side for this to be present.

o File list transfer time is the number of seconds that the sender spent sending the file list to the receiver.

o Total bytes sent is the count of all the bytes that rsync sent from the client side to the server side.

o Total bytes received is the count of all non-message bytes that rsync received by the client side from the server side. "Non-mesâАР
sage" bytes means that we don't count the bytes for a verbose message that the server sent to us, which makes the stats more conâАР
sistent.

--8-bit-output, -8
This tells rsync to leave all high-bit characters unescaped in the output instead of trying to test them to see if they're valid in the
current locale and escaping the invalid ones. All control characters (but never tabs) are always escaped, regardless of this option's
setting.

The escape idiom that started in 2.6.7 is to output a literal backslash (\) and a hash (), followed by exactly 3 octal digits. For examâАР
ple, a newline would output as "\012". A literal backslash that is in a filename is not escaped unless it is followed by a hash and 3
digits (0-9).

--human-readable, -h
Output numbers in a more human-readable format. There are 3 possible levels: (1) output numbers with a separator between each set of 3
digits (either a comma or a period, depending on if the decimal point is represented by a period or a comma); (2) output numbers in units
of 1000 (with a character suffix for larger units -- see below); (3) output numbers in units of 1024.

The default is human-readable level 1. Each -h option increases the level by one. You can take the level down to 0 (to output numbers as
pure digits) by specifying the --no-human-readable (--no-h) option.

The unit letters that are appended in levels 2 and 3 are: K (kilo), M (mega), G (giga), T (tera), or P (peta). For example, a
1234567-byte file would output as 1.23M in level-2 (assuming that a period is your local decimal point).

Backward compatibility note: versions of rsync prior to 3.1.0 do not support human-readable level 1, and they default to level 0. Thus,
specifying one or two -h options will behave in a comparable manner in old and new versions as long as you didn't specify a --no-h option
prior to one or more -h options. See the --list-only option for one difference.

--partial
By default, rsync will delete any partially transferred file if the transfer is interrupted. In some circumstances it is more desirable
to keep partially transferred files. Using the --partial option tells rsync to keep the partial file which should make a subsequent
transfer of the rest of the file much faster.

--partial-dir=DIR
A better way to keep partial files than the --partial option is to specify a DIR that will be used to hold the partial data (instead of
writing it out to the destination file). On the next transfer, rsync will use a file found in this dir as data to speed up the resumption
of the transfer and then delete it after it has served its purpose.

Note that if --whole-file is specified (or implied), any partial-dir file that is found for a file that is being updated will simply be
removed (since rsync is sending files without using rsync's delta-transfer algorithm).

Rsync will create the DIR if it is missing (just the last dir -- not the whole path). This makes it easy to use a relative path (such as
"--partial-dir=.rsync-partial") to have rsync create the partial-directory in the destination file's directory when needed, and then reâАР
move it again when the partial file is deleted. Note that the directory is only removed if it is a relative pathname, as it is expected
that an absolute path is to a directory that is reserved for partial-dir work.

If the partial-dir value is not an absolute path, rsync will add an exclude rule at the end of all your existing excludes. This will preâАР
vent the sending of any partial-dir files that may exist on the sending side, and will also prevent the untimely deletion of partial-dir
items on the receiving side. An example: the above --partial-dir option would add the equivalent of "-f '-p .rsync-partial/'" at the end
of any other filter rules.

If you are supplying your own exclude rules, you may need to add your own exclude/hide/protect rule for the partial-dir because (1) the
auto-added rule may be ineffective at the end of your other rules, or (2) you may wish to override rsync's exclude choice. For instance,
if you want to make rsync clean-up any left-over partial-dirs that may be lying around, you should specify --delete-after and add a "risk"
filter rule, e.g. -f 'R .rsync-partial/'. (Avoid using --delete-before or --delete-during unless you don't need rsync to use any of the
left-over partial-dir data during the current run.)

IMPORTANT: the --partial-dir should not be writable by other users or it is a security risk. E.g. AVOID "/tmp".

You can also set the partial-dir value the RSYNC_PARTIAL_DIR environment variable. Setting this in the environment does not force --parâАР
tial to be enabled, but rather it affects where partial files go when --partial is specified. For instance, instead of using --partial-
dir=.rsync-tmp along with --progress, you could set RSYNC_PARTIAL_DIR=.rsync-tmp in your environment and then just use the -P option to
turn on the use of the .rsync-tmp dir for partial transfers. The only times that the --partial option does not look for this environment
value are (1) when --inplace was specified (since --inplace conflicts with --partial-dir), and (2) when --delay-updates was specified (see
below).

When a modern rsync resumes the transfer of a file in the partial-dir, that partial file is now updated in-place instead of creating yet
another tmp-file copy (so it maxes out at dest + tmp instead of dest + partial + tmp). This requires both ends of the transfer to be at
least version 3.2.0.

For the purposes of the daemon-config's "refuse options" setting, --partial-dir does not imply --partial. This is so that a refusal of
the --partial option can be used to disallow the overwriting of destination files with a partial transfer, while still allowing the safer
idiom provided by --partial-dir.

--delay-updates
This option puts the temporary file from each updated file into a holding directory until the end of the transfer, at which time all the
files are renamed into place in rapid succession. This attempts to make the updating of the files a little more atomic. By default the
files are placed into a directory named .~tmp~ in each file's destination directory, but if you've specified the --partial-dir option,
that directory will be used instead. See the comments in the --partial-dir section for a discussion of how this .~tmp~ dir will be exâАР
cluded from the transfer, and what you can do if you want rsync to cleanup old .~tmp~ dirs that might be lying around. Conflicts with
--inplace and --append.

This option implies --no-inc-recursive since it needs the full file list in memory in order to be able to iterate over it at the end.

This option uses more memory on the receiving side (one bit per file transferred) and also requires enough free disk space on the receivâАР
ing side to hold an additional copy of all the updated files. Note also that you should not use an absolute path to --partial-dir unless
(1) there is no chance of any of the files in the transfer having the same name (since all the updated files will be put into a single diâАР
rectory if the path is absolute) and (2) there are no mount points in the hierarchy (since the delayed updates will fail if they can't be
renamed into place).

See also the "atomic-rsync" perl script in the "support" subdir for an update algorithm that is even more atomic (it uses --link-dest and
a parallel hierarchy of files).

--prune-empty-dirs, -m
This option tells the receiving rsync to get rid of empty directories from the file-list, including nested directories that have no non-
directory children. This is useful for avoiding the creation of a bunch of useless directories when the sending rsync is recursively
scanning a hierarchy of files using include/exclude/filter rules.

Note that the use of transfer rules, such as the --min-size option, does not affect what goes into the file list, and thus does not leave
directories empty, even if none of the files in a directory match the transfer rule.

Because the file-list is actually being pruned, this option also affects what directories get deleted when a delete is active. However,
keep in mind that excluded files and directories can prevent existing items from being deleted due to an exclude both hiding source files
and protecting destination files. See the perishable filter-rule option for how to avoid this.

You can prevent the pruning of certain empty directories from the file-list by using a global "protect" filter. For instance, this option
would ensure that the directory "emptydir" was kept in the file-list:

--filter 'protect emptydir/'

Here's an example that copies all .pdf files in a hierarchy, only creating the necessary destination directories to hold the .pdf files,
and ensures that any superfluous files and directories in the destination are removed (note the hide filter of non-directories being used
instead of an exclude):

rsync -avm --del --include='*.pdf' -f 'hide,! */' src/ dest

If you didn't want to remove superfluous destination files, the more time-honored options of --include='/' --exclude='' would work fine
in place of the hide-filter (if that is more natural to you).

--progress
This option tells rsync to print information showing the progress of the transfer. This gives a bored user something to watch. With a
modern rsync this is the same as specifying --info=flist2,name,progress, but any user-supplied settings for those info flags takes preceâАР
dence (e.g. "--info=flist0 --progress").

While rsync is transferring a regular file, it updates a progress line that looks like this:

782448 63% 110.64kB/s 0:00:04

In this example, the receiver has reconstructed 782448 bytes or 63% of the sender's file, which is being reconstructed at a rate of 110.64
kilobytes per second, and the transfer will finish in 4 seconds if the current rate is maintained until the end.

These statistics can be misleading if rsync's delta-transfer algorithm is in use. For example, if the sender's file consists of the basis
file followed by additional data, the reported rate will probably drop dramatically when the receiver gets to the literal data, and the
transfer will probably take much longer to finish than the receiver estimated as it was finishing the matched part of the file.

When the file transfer finishes, rsync replaces the progress line with a summary line that looks like this:

1,238,099 100% 146.38kB/s 0:00:08 (xfr#5, to-chk=169/396)

In this example, the file was 1,238,099 bytes long in total, the average rate of transfer for the whole file was 146.38 kilobytes per secâАР
ond over the 8 seconds that it took to complete, it was the 5th transfer of a regular file during the current rsync session, and there are
169 more files for the receiver to check (to see if they are up-to-date or not) remaining out of the 396 total files in the file-list.

In an incremental recursion scan, rsync won't know the total number of files in the file-list until it reaches the ends of the scan, but
since it starts to transfer files during the scan, it will display a line with the text "ir-chk" (for incremental recursion check) instead
of "to-chk" until the point that it knows the full size of the list, at which point it will switch to using "to-chk". Thus, seeing "ir-
chk" lets you know that the total count of files in the file list is still going to increase (and each time it does, the count of files
left to check will increase by the number of the files added to the list).

-P The -P option is equivalent to --partial --progress. Its purpose is to make it much easier to specify these two options for a long transâАР
fer that may be interrupted.

There is also a --info=progress2 option that outputs statistics based on the whole transfer, rather than individual files. Use this flag
without outputting a filename (e.g. avoid -v or specify --info=name0) if you want to see how the transfer is doing without scrolling the
screen with a lot of names. (You don't need to specify the --progress option in order to use --info=progress2.)

Finally, you can get an instant progress report by sending rsync a signal of either SIGINFO or SIGVTALRM. On BSD systems, a SIGINFO is
generated by typing a Ctrl+T (Linux doesn't currently support a SIGINFO signal). When the client-side process receives one of those sigâАР
nals, it sets a flag to output a single progress report which is output when the current file transfer finishes (so it may take a little
time if a big file is being handled when the signal arrives). A filename is output (if needed) followed by the --info=progress2 format of
progress info. If you don't know which of the 3 rsync processes is the client process, it's OK to signal all of them (since the non-
client processes ignore the signal).

CAUTION: sending SIGVTALRM to an older rsync (pre-3.2.0) will kill it.

--password-file=FILE
This option allows you to provide a password for accessing an rsync daemon via a file or via standard input if FILE is -. The file should
contain just the password on the first line (all other lines are ignored). Rsync will exit with an error if FILE is world readable or if
a root-run rsync command finds a non-root-owned file.

This option does not supply a password to a remote shell transport such as ssh; to learn how to do that, consult the remote shell's docuâАР
mentation. When accessing an rsync daemon using a remote shell as the transport, this option only comes into effect after the remote
shell finishes its authentication (i.e. if you have also specified a password in the daemon's config file).

--early-input=FILE
This option allows rsync to send up to 5K of data to the "early exec" script on its stdin. One possible use of this data is to give the
script a secret that can be used to mount an encrypted filesystem (which you should unmount in the the "post-xfer exec" script).

The daemon must be at least version 3.2.1.

--list-only
This option will cause the source files to be listed instead of transferred. This option is inferred if there is a single source arg and
no destination specified, so its main uses are: (1) to turn a copy command that includes a destination arg into a file-listing command, or
(2) to be able to specify more than one source arg (note: be sure to include the destination). Caution: keep in mind that a source arg
with a wild-card is expanded by the shell into multiple args, so it is never safe to try to list such an arg without using this option.
For example:

rsync -av --list-only foo* dest/

Starting with rsync 3.1.0, the sizes output by --list-only are affected by the --human-readable option. By default they will contain
digit separators, but higher levels of readability will output the sizes with unit suffixes. Note also that the column width for the size
output has increased from 11 to 14 characters for all human-readable levels. Use --no-h if you want just digits in the sizes, and the old
column width of 11 characters.

Compatibility note: when requesting a remote listing of files from an rsync that is version 2.6.3 or older, you may encounter an error if
you ask for a non-recursive listing. This is because a file listing implies the --dirs option w/o --recursive, and older rsyncs don't
have that option. To avoid this problem, either specify the --no-dirs option (if you don't need to expand a directory's content), or turn
on recursion and exclude the content of subdirectories: -r --exclude='/*/*'.

--bwlimit=RATE
This option allows you to specify the maximum transfer rate for the data sent over the socket, specified in units per second. The RATE
value can be suffixed with a string to indicate a size multiplier, and may be a fractional value (e.g. "--bwlimit=1.5m"). If no suffix is
specified, the value will be assumed to be in units of 1024 bytes (as if "K" or "KiB" had been appended). See the --max-size option for a
description of all the available suffixes. A value of 0 specifies no limit.

For backward-compatibility reasons, the rate limit will be rounded to the nearest KiB unit, so no rate smaller than 1024 bytes per second
is possible.

Rsync writes data over the socket in blocks, and this option both limits the size of the blocks that rsync writes, and tries to keep the
average transfer rate at the requested limit. Some burstiness may be seen where rsync writes out a block of data and then sleeps to bring
the average rate into compliance.

Due to the internal buffering of data, the --progress option may not be an accurate reflection on how fast the data is being sent. This
is because some files can show up as being rapidly sent when the data is quickly buffered, while other can show up as very slow when the
flushing of the output buffer occurs. This may be fixed in a future version.

`--stop-after=MINS
This option tells rsync to stop copying when the specified number of minutes has elapsed.

Rsync also accepts an earlier version of this option: --time-limit=MINS.

For maximal flexibility, rsync does not communicate this option to the remote rsync since it is usually enough that one side of the conâАР
nection quits as specified. This allows the option's use even when only one side of the connection supports it. You can tell the remote
side about the time limit using --remote-option (-M), should the need arise.

`--stop-at=y-m-dTh:m
This option tells rsync to stop copying when the specified point in time has been reached. The date & time can be fully specified in a nuâАР
meric format of year-month-dayThour:minute (e.g. 2000-12-31T23:59) in the local timezone. You may choose to separate the date numbers usâАР
ing slashes instead of dashes.

The value can also be abbreviated in a variety of ways, such as specifying a 2-digit year and/or leaving off various values. In all
cases, the value will be taken to be the next possible point in time where the supplied information matches. If the value specifies the
current time or a past time, rsync exits with an error.

For example, "1-30" specifies the next January 30th (at midnight local time), "14:00" specifies the next 2 P.M., "1" specifies the next
1st of the month at midnight, "31" specifies the next month where we can stop on its 31st day, and ":59" specifies the next 59th minute
after the hour.

--write-batch=FILE
Record a file that can later be applied to another identical destination with --read-batch. See the "BATCH MODE" section for details, and
also the --only-write-batch option.

This option overrides the negotiated checksum & compress lists and always negotiates a choice based on old-school md5/md4/zlib choices.
If you want a more modern choice, use the --checksum-choice (--cc) and/or --compress-choice (--zc) options.

--only-write-batch=FILE
Works like --write-batch, except that no updates are made on the destination system when creating the batch. This lets you transport the
changes to the destination system via some other means and then apply the changes via --read-batch.

Note that you can feel free to write the batch directly to some portable media: if this media fills to capacity before the end of the
transfer, you can just apply that partial transfer to the destination and repeat the whole process to get the rest of the changes (as long
as you don't mind a partially updated destination system while the multi-update cycle is happening).

Also note that you only save bandwidth when pushing changes to a remote system because this allows the batched data to be diverted from
the sender into the batch file without having to flow over the wire to the receiver (when pulling, the sender is remote, and thus can't
write the batch).

--read-batch=FILE
Apply all of the changes stored in FILE, a file previously generated by --write-batch. If FILE is -, the batch data will be read from
standard input. See the "BATCH MODE" section for details.

--protocol=NUM
Force an older protocol version to be used. This is useful for creating a batch file that is compatible with an older version of rsync.
For instance, if rsync 2.6.4 is being used with the --write-batch option, but rsync 2.6.3 is what will be used to run the --read-batch opâАР
tion, you should use "--protocol=28" when creating the batch file to force the older protocol version to be used in the batch file (assumâАР
ing you can't upgrade the rsync on the reading system).

--iconv=CONVERT_SPEC
Rsync can convert filenames between character sets using this option. Using a CONVERT_SPEC of "." tells rsync to look up the default
character-set via the locale setting. Alternately, you can fully specify what conversion to do by giving a local and a remote charset
separated by a comma in the order --iconv=LOCAL,REMOTE, e.g. --iconv=utf8,iso88591. This order ensures that the option will stay the same
whether you're pushing or pulling files. Finally, you can specify either --no-iconv or a CONVERT_SPEC of "-" to turn off any conversion.
The default setting of this option is site-specific, and can also be affected via the RSYNC_ICONV environment variable.

For a list of what charset names your local iconv library supports, you can run "iconv --list".

If you specify the --protect-args option (-s), rsync will translate the filenames you specify on the command-line that are being sent to
the remote host. See also the --files-from option.

Note that rsync does not do any conversion of names in filter files (including include/exclude files). It is up to you to ensure that
you're specifying matching rules that can match on both sides of the transfer. For instance, you can specify extra include/exclude rules
if there are filename differences on the two sides that need to be accounted for.

When you pass an --iconv option to an rsync daemon that allows it, the daemon uses the charset specified in its "charset" configuration
parameter regardless of the remote charset you actually pass. Thus, you may feel free to specify just the local charset for a daemon
transfer (e.g. --iconv=utf8).

--ipv4, -4 or --ipv6, -6
Tells rsync to prefer IPv4/IPv6 when creating sockets or running ssh. This affects sockets that rsync has direct control over, such as
the outgoing socket when directly contacting an rsync daemon, as well as the forwarding of the -4 or -6 option to ssh when rsync can deâАР
duce that ssh is being used as the remote shell. For other remote shells you'll need to specify the "--rsh SHELL -4" option directly (or
whatever ipv4/ipv6 hint options it uses).

These options also exist in the --daemon mode section.

If rsync was complied without support for IPv6, the --ipv6 option will have no effect. The rsync --version output will contain "no IPv6"
if is the case.

--checksum-seed=NUM
Set the checksum seed to the integer NUM. This 4 byte checksum seed is included in each block and MD4 file checksum calculation (the more
modern MD5 file checksums don't use a seed). By default the checksum seed is generated by the server and defaults to the current time().
This option is used to set a specific checksum seed, which is useful for applications that want repeatable block checksums, or in the case
where the user wants a more random checksum seed. Setting NUM to 0 causes rsync to use the default of time() for checksum seed.

DAEMON OPTIONS

The options allowed when starting an rsync daemon are as follows:

--daemon
This tells rsync that it is to run as a daemon. The daemon you start running may be accessed using an rsync client using the host::module
or rsync://host/module/ syntax.

If standard input is a socket then rsync will assume that it is being run via inetd, otherwise it will detach from the current terminal
and become a background daemon. The daemon will read the config file (rsyncd.conf) on each connect made by a client and respond to reâАР
quests accordingly. See the rsyncd.conf(5) man page for more details.

--address=ADDRESS
By default rsync will bind to the wildcard address when run as a daemon with the --daemon option. The --address option allows you to
specify a specific IP address (or hostname) to bind to. This makes virtual hosting possible in conjunction with the --config option. See
also the "address" global option in the rsyncd.conf manpage.

--bwlimit=RATE
This option allows you to specify the maximum transfer rate for the data the daemon sends over the socket. The client can still specify a
smaller --bwlimit value, but no larger value will be allowed. See the client version of this option (above) for some extra details.

--config=FILE
This specifies an alternate config file than the default. This is only relevant when --daemon is specified. The default is
/etc/rsyncd.conf unless the daemon is running over a remote shell program and the remote user is not the super-user; in that case the deâАР
fault is rsyncd.conf in the current directory (typically $HOME).

--dparam=OVERRIDE, -M
This option can be used to set a daemon-config parameter when starting up rsync in daemon mode. It is equivalent to adding the parameter
at the end of the global settings prior to the first module's definition. The parameter names can be specified without spaces, if you so
desire. For instance:

rsync --daemon -M pidfile=/path/rsync.pid

--no-detach
When running as a daemon, this option instructs rsync to not detach itself and become a background process. This option is required when
running as a service on Cygwin, and may also be useful when rsync is supervised by a program such as daemontools or AIX's System ReâАР
source Controller. --no-detach is also recommended when rsync is run under a debugger. This option has no effect if rsync is run from
inetd or sshd.

--port=PORT
This specifies an alternate TCP port number for the daemon to listen on rather than the default of 873. See also the "port" global option
in the rsyncd.conf manpage.

--log-file=FILE
This option tells the rsync daemon to use the given log-file name instead of using the "log file" setting in the config file.

--log-file-format=FORMAT
This option tells the rsync daemon to use the given FORMAT string instead of using the "log format" setting in the config file. It also
enables "transfer logging" unless the string is empty, in which case transfer logging is turned off.

--sockopts
This overrides the socket options setting in the rsyncd.conf file and has the same syntax.

--verbose, -v
This option increases the amount of information the daemon logs during its startup phase. After the client connects, the daemon's verâАР
bosity level will be controlled by the options that the client used and the "max verbosity" setting in the module's config section.

--ipv4, -4 or --ipv6, -6
Tells rsync to prefer IPv4/IPv6 when creating the incoming sockets that the rsync daemon will use to listen for connections. One of these
options may be required in older versions of Linux to work around an IPv6 bug in the kernel (if you see an "address already in use" error
when nothing else is using the port, try specifying --ipv6 or --ipv4 when starting the daemon).

These options also exist in the regular rsync options section.

If rsync was complied without support for IPv6, the --ipv6 option will have no effect. The rsync --version output will contain "no IPv6"
if is the case.

--help, -h
When specified after --daemon, print a short help page describing the options available for starting an rsync daemon.

FILTER RULES

The filter rules allow for flexible selection of which files to transfer (include) and which files to skip (exclude). The rules either directly
specify include/exclude patterns or they specify a way to acquire more include/exclude patterns (e.g. to read them from a file).

As the list of files/directories to transfer is built, rsync checks each name to be transferred against the list of include/exclude patterns in
turn, and the first matching pattern is acted on: if it is an exclude pattern, then that file is skipped; if it is an include pattern then that
filename is not skipped; if no matching pattern is found, then the filename is not skipped.

Rsync builds an ordered list of filter rules as specified on the command-line. Filter rules have the following syntax:

RULE [PATTERN_OR_FILENAME]
RULE,MODIFIERS [PATTERN_OR_FILENAME]

You have your choice of using either short or long RULE names, as described below. If you use a short-named rule, the ',' separating the RULE
from the MODIFIERS is optional. The PATTERN or FILENAME that follows (when present) must come after either a single space or an underscore (_).
Here are the available rule prefixes:

exclude, '-'
specifies an exclude pattern.

include, '+'
specifies an include pattern.

merge, '.'
specifies a merge-file to read for more rules.

dir-merge, ':'
specifies a per-directory merge-file.

hide, 'H'
specifies a pattern for hiding files from the transfer.

show, 'S'
files that match the pattern are not hidden.

protect, 'P'
specifies a pattern for protecting files from deletion.

risk, 'R'
files that match the pattern are not protected.

clear, '!'
clears the current include/exclude list (takes no arg)

When rules are being read from a file, empty lines are ignored, as are whole-line comments that start with a '#' (filename rules that contain a
hash are unaffected).

Note that the --include & --exclude command-line options do not allow the full range of rule parsing as described above -- they only allow the
specification of include / exclude patterns plus a "!" token to clear the list (and the normal comment parsing when rules are read from a file).
If a pattern does not begin with "- " (dash, space) or "+ " (plus, space), then the rule will be interpreted as if "+ " (for an include option)
or "- " (for an exclude option) were prefixed to the string. A --filter option, on the other hand, must always contain either a short or long
rule name at the start of the rule.

Note also that the --filter, --include, and --exclude options take one rule/pattern each. To add multiple ones, you can repeat the options on
the command-line, use the merge-file syntax of the --filter option, or the --include-from / --exclude-from options.

INCLUDE/EXCLUDE PATTERN RULES

You can include and exclude files by specifying patterns using the "+", "-", etc. filter rules (as introduced in the FILTER RULES section above).
The include/exclude rules each specify a pattern that is matched against the names of the files that are going to be transferred. These patterns
can take several forms:

o if the pattern starts with a / then it is anchored to a particular spot in the hierarchy of files, otherwise it is matched against the end
of the pathname. This is similar to a leading ^ in regular expressions. Thus /foo would match a name of "foo" at either the "root of the
transfer" (for a global rule) or in the merge-file's directory (for a per-directory rule). An unqualified foo would match a name of "foo"
anywhere in the tree because the algorithm is applied recursively from the top down; it behaves as if each path component gets a turn at
being the end of the filename. Even the unanchored "sub/foo" would match at any point in the hierarchy where a "foo" was found within a
directory named "sub". See the section on ANCHORING INCLUDE/EXCLUDE PATTERNS for a full discussion of how to specify a pattern that
matches at the root of the transfer.

o if the pattern ends with a / then it will only match a directory, not a regular file, symlink, or device.

o rsync chooses between doing a simple string match and wildcard matching by checking if the pattern contains one of these three wildcard
characters: '*', '?', and '[' .

o a '*' matches any path component, but it stops at slashes.

o use '**' to match anything, including slashes.

o a '?' matches any character except a slash (/).

o a '[' introduces a character class, such as [a-z] or [[:alpha:]].

o in a wildcard pattern, a backslash can be used to escape a wildcard character, but it is matched literally when no wildcards are present.
This means that there is an extra level of backslash removal when a pattern contains wildcard characters compared to a pattern that has
none. e.g. if you add a wildcard to "foo\bar" (which matches the backslash) you would need to use "foo\\bar*" to avoid the "\b" becoming
just "b".

o if the pattern contains a / (not counting a trailing /) or a "**", then it is matched against the full pathname, including any leading diâАР
rectories. If the pattern doesn't contain a / or a "**", then it is matched only against the final component of the filename. (Remember
that the algorithm is applied recursively so "full filename" can actually be any portion of a path from the starting directory on down.)

o a trailing "dir_name/***" will match both the directory (as if "dir_name/" had been specified) and everything in the directory (as if
"dir_name/**" had been specified). This behavior was added in version 2.6.7.

Note that, when using the --recursive (-r) option (which is implied by -a), every subdir component of every path is visited left to right, with
each directory having a chance for exclusion before its content. In this way include/exclude patterns are applied recursively to the pathname of
each node in the filesystem's tree (those inside the transfer). The exclude patterns short-circuit the directory traversal stage as rsync finds
the files to send.

For instance, to include "/foo/bar/baz", the directories "/foo" and "/foo/bar" must not be excluded. Excluding one of those parent directories
prevents the examination of its content, cutting off rsync's recursion into those paths and rendering the include for "/foo/bar/baz" ineffectual
(since rsync can't match something it never sees in the cut-off section of the directory hierarchy).

The concept path exclusion is particularly important when using a trailing '*' rule. For instance, this won't work:

+ /some/path/this-file-will-not-be-found
+ /file-is-included
- *

This fails because the parent directory "some" is excluded by the '*' rule, so rsync never visits any of the files in the "some" or "some/path"
directories. One solution is to ask for all directories in the hierarchy to be included by using a single rule: "+ */" (put it somewhere before
the "- *" rule), and perhaps use the --prune-empty-dirs option. Another solution is to add specific include rules for all the parent dirs that
need to be visited. For instance, this set of rules works fine:

+ /some/
+ /some/path/
+ /some/path/this-file-is-found
+ /file-also-included
- *

Here are some examples of exclude/include matching:

o "- *.o" would exclude all names matching *.o

o "- /foo" would exclude a file (or directory) named foo in the transfer-root directory

o "- foo/" would exclude any directory named foo

o "- /foo/*/bar" would exclude any file named bar which is at two levels below a directory named foo in the transfer-root directory

o "- /foo/**/bar" would exclude any file named bar two or more levels below a directory named foo in the transfer-root directory

o The combination of "+ */", "+ *.c", and "- *" would include all directories and C source files but nothing else (see also the --prune-
empty-dirs option)

o The combination of "+ foo/", "+ foo/bar.c", and "- " would include only the foo directory and foo/bar.c (the foo directory must be exâАР
plicitly included or it would be excluded by the "")

The following modifiers are accepted after a "+" or "-":

o A / specifies that the include/exclude rule should be matched against the absolute pathname of the current item. For example,
"-/ /etc/passwd" would exclude the passwd file any time the transfer was sending files from the "/etc" directory, and "-/ subdir/foo"
would always exclude "foo" when it is in a dir named "subdir", even if "foo" is at the root of the current transfer.

o A ! specifies that the include/exclude should take effect if the pattern fails to match. For instance, "-! */" would exclude all non-diâАР
rectories.

o A C is used to indicate that all the global CVS-exclude rules should be inserted as excludes in place of the "-C". No arg should follow.

o An s is used to indicate that the rule applies to the sending side. When a rule affects the sending side, it prevents files from being
transferred. The default is for a rule to affect both sides unless --delete-excluded was specified, in which case default rules become
sender-side only. See also the hide (H) and show (S) rules, which are an alternate way to specify sending-side includes/excludes.

o An r is used to indicate that the rule applies to the receiving side. When a rule affects the receiving side, it prevents files from beâАР
ing deleted. See the s modifier for more info. See also the protect (P) and risk (R) rules, which are an alternate way to specify reâАР
ceiver-side includes/excludes.

o A p indicates that a rule is perishable, meaning that it is ignored in directories that are being deleted. For instance, the -C option's
default rules that exclude things like "CVS" and "*.o" are marked as perishable, and will not prevent a directory that was removed on the
source from being deleted on the destination.

o An x indicates that a rule affects xattr names in xattr copy/delete operations (and is thus ignored when matching file/dir names). If no
xattr-matching rules are specified, a default xattr filtering rule is used (see the --xattrs option).

MERGE-FILE FILTER RULES

You can merge whole files into your filter rules by specifying either a merge (.) or a dir-merge (:) filter rule (as introduced in the FILTER
RULES section above).

There are two kinds of merged files -- single-instance ('.') and per-directory (':'). A single-instance merge file is read one time, and its
rules are incorporated into the filter list in the place of the "." rule. For per-directory merge files, rsync will scan every directory that it
traverses for the named file, merging its contents when the file exists into the current list of inherited rules. These per-directory rule files
must be created on the sending side because it is the sending side that is being scanned for the available files to transfer. These rule files
may also need to be transferred to the receiving side if you want them to affect what files don't get deleted (see PER-DIRECTORY RULES AND DELETE
below).

Some examples:

merge /etc/rsync/default.rules
. /etc/rsync/default.rules
dir-merge .per-dir-filter
dir-merge,n- .non-inherited-per-dir-excludes
:n- .non-inherited-per-dir-excludes

The following modifiers are accepted after a merge or dir-merge rule:

o A - specifies that the file should consist of only exclude patterns, with no other rule-parsing except for in-file comments.

o A + specifies that the file should consist of only include patterns, with no other rule-parsing except for in-file comments.

o A C is a way to specify that the file should be read in a CVS-compatible manner. This turns on 'n', 'w', and '-', but also allows the
list-clearing token (!) to be specified. If no filename is provided, ".cvsignore" is assumed.

o A e will exclude the merge-file name from the transfer; e.g. "dir-merge,e .rules" is like "dir-merge .rules" and "- .rules".

o An n specifies that the rules are not inherited by subdirectories.

o A w specifies that the rules are word-split on whitespace instead of the normal line-splitting. This also turns off comments. Note: the
space that separates the prefix from the rule is treated specially, so "- foo + bar" is parsed as two rules (assuming that prefix-parsing
wasn't also disabled).

o You may also specify any of the modifiers for the "+" or "-" rules (above) in order to have the rules that are read in from the file deâАР
fault to having that modifier set (except for the ! modifier, which would not be useful). For instance, "merge,-/ .excl" would treat the
contents of .excl as absolute-path excludes, while "dir-merge,s .filt" and ":sC" would each make all their per-directory rules apply only
on the sending side. If the merge rule specifies sides to affect (via the s or r modifier or both), then the rules in the file must not
specify sides (via a modifier or a rule prefix such as hide).

Per-directory rules are inherited in all subdirectories of the directory where the merge-file was found unless the 'n' modifier was used. Each
subdirectory's rules are prefixed to the inherited per-directory rules from its parents, which gives the newest rules a higher priority than the
inherited rules. The entire set of dir-merge rules are grouped together in the spot where the merge-file was specified, so it is possible to
override dir-merge rules via a rule that got specified earlier in the list of global rules. When the list-clearing rule ("!") is read from a
per-directory file, it only clears the inherited rules for the current merge file.

Another way to prevent a single rule from a dir-merge file from being inherited is to anchor it with a leading slash. Anchored rules in a per-
directory merge-file are relative to the merge-file's directory, so a pattern "/foo" would only match the file "foo" in the directory where the
dir-merge filter file was found.

Here's an example filter file which you'd specify via --filter=". file":

merge /home/user/.global-filter
- *.gz
dir-merge .rules
+ *.[ch]
- .o
- foo

This will merge the contents of the /home/user/.global-filter file at the start of the list and also turns the ".rules" filename into a per-diâАР
rectory filter file. All rules read in prior to the start of the directory scan follow the global anchoring rules (i.e. a leading slash matches
at the root of the transfer).

If a per-directory merge-file is specified with a path that is a parent directory of the first transfer directory, rsync will scan all the parent
dirs from that starting point to the transfer directory for the indicated per-directory file. For instance, here is a common filter (see -F):

--filter=': /.rsync-filter'

That rule tells rsync to scan for the file .rsync-filter in all directories from the root down through the parent directory of the transfer prior
to the start of the normal directory scan of the file in the directories that are sent as a part of the transfer. (Note: for an rsync daemon, the
root is always the same as the module's "path".)

Some examples of this pre-scanning for per-directory files:

rsync -avF /src/path/ /dest/dir
rsync -av --filter=': ../../.rsync-filter' /src/path/ /dest/dir
rsync -av --filter=': .rsync-filter' /src/path/ /dest/dir

The first two commands above will look for ".rsync-filter" in "/" and "/src" before the normal scan begins looking for the file in "/src/path"
and its subdirectories. The last command avoids the parent-dir scan and only looks for the ".rsync-filter" files in each directory that is a
part of the transfer.

If you want to include the contents of a ".cvsignore" in your patterns, you should use the rule ":C", which creates a dir-merge of the .cvsignore
file, but parsed in a CVS-compatible manner. You can use this to affect where the --cvs-exclude (-C) option's inclusion of the per-directory
.cvsignore file gets placed into your rules by putting the ":C" wherever you like in your filter rules. Without this, rsync would add the dir-
merge rule for the .cvsignore file at the end of all your other rules (giving it a lower priority than your command-line rules). For example:

cat <<EOT | rsync -avC --filter='. -' a/ b
+ foo.o
:C
- .old
EOT
rsync -avC --include=foo.o -f :C --exclude='.old' a/ b

Both of the above rsync commands are identical. Each one will merge all the per-directory .cvsignore rules in the middle of the list rather than
at the end. This allows their dir-specific rules to supersede the rules that follow the :C instead of being subservient to all your rules. To
affect the other CVS exclude rules (i.e. the default list of exclusions, the contents of $HOME/.cvsignore, and the value of $CVSIGNORE) you
should omit the -C command-line option and instead insert a "-C" rule into your filter rules; e.g. "--filter=-C".

LIST-CLEARING FILTER RULE

       You can clear the current include/exclude list by using the "!" filter rule (as introduced in the FILTER RULES  section  above).   The  "current"
       list  is either the global list of rules (if the rule is encountered while parsing the filter options) or a set of per-directory rules (which are
       inherited in their own sub-list, so a subdirectory can use this to clear out the parent's rules).

ANCHORING INCLUDE/EXCLUDE PATTERNS

       As mentioned earlier, global include/exclude patterns are anchored at the "root of the transfer" (as opposed to per-directory patterns, which are
       anchored  at  the  merge-file's  directory).  If you think of the transfer as a subtree of names that are being sent from sender to receiver, the
       transfer-root is where the tree starts to be duplicated in the destination directory.  This root governs where  patterns  that  start  with  a  /
       match.

       Because the matching is relative to the transfer-root, changing the trailing slash on a source path or changing your use of the --relative option
       affects the path you need to use in your matching (in addition to changing how much of the file tree is duplicated on the destination host).  The
       following examples demonstrate this.

       Let's  say  that  we want to match two source files, one with an absolute path of "/home/me/foo/bar", and one with a path of "/home/you/bar/baz".
       Here is how the various command choices differ for a 2-source transfer:

           Example cmd: rsync -a /home/me /home/you /dest
           +/- pattern: /me/foo/bar
           +/- pattern: /you/bar/baz
           Target file: /dest/me/foo/bar
           Target file: /dest/you/bar/baz

           Example cmd: rsync -a /home/me/ /home/you/ /dest
           +/- pattern: /foo/bar               (note missing "me")
           +/- pattern: /bar/baz               (note missing "you")
           Target file: /dest/foo/bar
           Target file: /dest/bar/baz

           Example cmd: rsync -a --relative /home/me/ /home/you /dest
           +/- pattern: /home/me/foo/bar       (note full path)
           +/- pattern: /home/you/bar/baz      (ditto)
           Target file: /dest/home/me/foo/bar
           Target file: /dest/home/you/bar/baz

           Example cmd: cd /home; rsync -a --relative me/foo you/ /dest
           +/- pattern: /me/foo/bar      (starts at specified path)
           +/- pattern: /you/bar/baz     (ditto)
           Target file: /dest/me/foo/bar
           Target file: /dest/you/bar/baz

       The easiest way to see what name you should filter is to just look at the output when using --verbose and put a / in front of the name  (use  the
       --dry-run option if you're not yet ready to copy any files).

PER-DIRECTORY RULES AND DELETE

       Without  a  delete  option, per-directory rules are only relevant on the sending side, so you can feel free to exclude the merge files themselves
       without affecting the transfer.  To make this easy, the 'e' modifier adds this exclude for you, as seen in these two equivalent commands:

           rsync -av --filter=': .excl' --exclude=.excl host:src/dir /dest
           rsync -av --filter=':e .excl' host:src/dir /dest

       However, if you want to do a delete on the receiving side AND you want some files to be excluded from being deleted, you'll need to be sure  that
       the receiving side knows what files to exclude.  The easiest way is to include the per-directory merge files in the transfer and use --delete-afâАР
       ter, because this ensures that the receiving side gets all the same exclude rules as the sending side before it tries to delete anything:

           rsync -avF --delete-after host:src/dir /dest

       However, if the merge files are not a part of the transfer, you'll need to either specify some global exclude rules (i.e. specified on  the  comâАР
       mand  line),  or  you'll need to maintain your own per-directory merge files on the receiving side.  An example of the first is this (assume that
       the remote .rules files exclude themselves):

           rsync -av --filter=': .rules' --filter='. /my/extra.rules'
              --delete host:src/dir /dest

       In the above example the extra.rules file can affect both sides of the transfer, but (on the sending side) the rules are subservient to the rules
       merged from the .rules files because they were specified after the per-directory merge rule.

       In  one  final example, the remote side is excluding the .rsync-filter files from the transfer, but we want to use our own .rsync-filter files to
       control what gets deleted on the receiving side.  To do this we must specifically exclude the per-directory merge files (so that they  don't  get
       deleted) and then put rules into the local files to control what else should not get deleted.  Like one of these commands:

           rsync -av --filter=':e /.rsync-filter' --delete \
               host:src/dir /dest
           rsync -avFF --delete host:src/dir /dest

BATCH MODE

Batch mode can be used to apply the same set of updates to many identical systems. Suppose one has a tree which is replicated on a number of
hosts. Now suppose some changes have been made to this source tree and those changes need to be propagated to the other hosts. In order to do
this using batch mode, rsync is run with the write-batch option to apply the changes made to the source tree to one of the destination trees.
The write-batch option causes the rsync client to store in a "batch file" all the information needed to repeat this operation against other,
identical destination trees.

Generating the batch file once saves having to perform the file status, checksum, and data block generation more than once when updating multiple
destination trees. Multicast transport protocols can be used to transfer the batch update files in parallel to many hosts at once, instead of
sending the same data to every host individually.

To apply the recorded changes to another destination tree, run rsync with the read-batch option, specifying the name of the same batch file, and
the destination tree. Rsync updates the destination tree using the information stored in the batch file.

For your convenience, a script file is also created when the write-batch option is used: it will be named the same as the batch file with ".sh"
appended. This script file contains a command-line suitable for updating a destination tree using the associated batch file. It can be executed
using a Bourne (or Bourne-like) shell, optionally passing in an alternate destination tree pathname which is then used instead of the original
destination path. This is useful when the destination tree path on the current host differs from the one used to create the batch file.

Examples:

$ rsync --write-batch=foo -a host:/source/dir/ /adest/dir/
$ scp foo* remote:
$ ssh remote ./foo.sh /bdest/dir/

$ rsync --write-batch=foo -a /source/dir/ /adest/dir/
$ ssh remote rsync --read-batch=- -a /bdest/dir/ <foo

In these examples, rsync is used to update /adest/dir/ from /source/dir/ and the information to repeat this operation is stored in "foo" and
"foo.sh". The host "remote" is then updated with the batched data going into the directory /bdest/dir. The differences between the two examples
reveals some of the flexibility you have in how you deal with batches:

o The first example shows that the initial copy doesn't have to be local -- you can push or pull data to/from a remote host using either the
remote-shell syntax or rsync daemon syntax, as desired.

o The first example uses the created "foo.sh" file to get the right rsync options when running the read-batch command on the remote host.

o The second example reads the batch data via standard input so that the batch file doesn't need to be copied to the remote machine first.
This example avoids the foo.sh script because it needed to use a modified --read-batch option, but you could edit the script file if you
wished to make use of it (just be sure that no other option is trying to use standard input, such as the "--exclude-from=-" option).

Caveats:

The read-batch option expects the destination tree that it is updating to be identical to the destination tree that was used to create the batch
update fileset. When a difference between the destination trees is encountered the update might be discarded with a warning (if the file appears
to be up-to-date already) or the file-update may be attempted and then, if the file fails to verify, the update discarded with an error. This
means that it should be safe to re-run a read-batch operation if the command got interrupted. If you wish to force the batched-update to always
be attempted regardless of the file's size and date, use the -I option (when reading the batch). If an error occurs, the destination tree will
probably be in a partially updated state. In that case, rsync can be used in its regular (non-batch) mode of operation to fix up the destination
tree.

The rsync version used on all destinations must be at least as new as the one used to generate the batch file. Rsync will die with an error if
the protocol version in the batch file is too new for the batch-reading rsync to handle. See also the --protocol option for a way to have the
creating rsync generate a batch file that an older rsync can understand. (Note that batch files changed format in version 2.6.3, so mixing verâАР
sions older than that with newer versions will not work.)

When reading a batch file, rsync will force the value of certain options to match the data in the batch file if you didn't set them to the same
as the batch-writing command. Other options can (and should) be changed. For instance --write-batch changes to --read-batch, --files-from is
dropped, and the --filter / --include / --exclude options are not needed unless one of the --delete options is specified.

The code that creates the BATCH.sh file transforms any filter/include/exclude options into a single list that is appended as a "here" document to
the shell script file. An advanced user can use this to modify the exclude list if a change in what gets deleted by --delete is desired. A norâАР
mal user can ignore this detail and just use the shell script as an easy way to run the appropriate --read-batch command for the batched data.

The original batch mode in rsync was based on "rsync+", but the latest version uses a new implementation.

SYMBOLIC LINKS

Three basic behaviors are possible when rsync encounters a symbolic link in the source directory.

By default, symbolic links are not transferred at all. A message “skipping non-regular” file is emitted for any symlinks that exist.

If –links is specified, then symlinks are recreated with the same target on the destination. Note that –archive implies –links.

If –copy-links is specified, then symlinks are “collapsed” by copying their referent, rather than the symlink.

       Rsync  can  also  distinguish "safe" and "unsafe" symbolic links.  An example where this might be used is a web site mirror that wishes to ensure
       that the rsync module that is copied does not include symbolic links to /etc/passwd in the public section of the site.  Using --copy-unsafe-links
       will  cause  any links to be copied as the file they point to on the destination.  Using --safe-links will cause unsafe links to be omitted altoâАР
       gether. (Note that you must specify --links for --safe-links to have any effect.)

       Symbolic links are considered unsafe if they are absolute symlinks (start with /), empty, or if they contain enough ".."   components  to  ascend
       from the directory being copied.

       Here's  a  summary  of how the symlink options are interpreted.  The list is in order of precedence, so if your combination of options isn't menâАР
       tioned, use the first line that is a complete subset of your options:

       --copy-links
              Turn all symlinks into normal files (leaving no symlinks for any other options to affect).

       --links --copy-unsafe-links
              Turn all unsafe symlinks into files and duplicate all safe symlinks.

       --copy-unsafe-links
              Turn all unsafe symlinks into files, noisily skip all safe symlinks.

       --links --safe-links
              Duplicate safe symlinks and skip unsafe ones.

       --links
              Duplicate all symlinks.

DIAGNOSTICS

       rsync occasionally produces error messages that may seem a little cryptic.  The one that seems to cause the most confusion is  "protocol  version
       mismatch -- is your shell clean?".

       This  message is usually caused by your startup scripts or remote shell facility producing unwanted garbage on the stream that rsync is using for
       its transport.  The way to diagnose this problem is to run your remote shell like this:

           ssh remotehost /bin/true > out.dat

       then look at out.dat.  If everything is working correctly then out.dat should be a zero length file.  If you are getting  the  above  error  from
       rsync  then  you will probably find that out.dat contains some text or data.  Look at the contents and try to work out what is producing it.  The
       most common cause is incorrectly configured shell startup scripts (such as .cshrc or .profile) that contain output statements for non-interactive
       logins.

       If you are having trouble debugging filter patterns, then try specifying the -vv option.  At this level of verbosity rsync will show why each inâАР
       dividual file is included or excluded.

EXIT VALUES

0 Success

1 Syntax or usage error

2 Protocol incompatibility

3 Errors selecting input/output files, dirs

       4      Requested action not supported: an attempt was made to manipulate 64-bit files on a platform that cannot support them; or  an  option  was
              specified that is supported by the client and not by the server.

       5      Error starting client-server protocol

       6      Daemon unable to append to log-file

       10     Error in socket I/O

       11     Error in file I/O

       12     Error in rsync protocol data stream

       13     Errors with program diagnostics

       14     Error in IPC code

       20     Received SIGUSR1 or SIGINT

       21     Some error returned by waitpid()

       22     Error allocating core memory buffers

       23     Partial transfer due to error

       24     Partial transfer due to vanished source files

       25     The --max-delete limit stopped deletions

       30     Timeout in data send/receive

       35     Timeout waiting for daemon connection

ENVIRONMENT VARIABLES

CVSIGNORE
The CVSIGNORE environment variable supplements any ignore patterns in .cvsignore files. See the --cvs-exclude option for more details.

RSYNC_ICONV
Specify a default --iconv setting using this environment variable. (First supported in 3.0.0.)

RSYNC_PROTECT_ARGS
Specify a non-zero numeric value if you want the --protect-args option to be enabled by default, or a zero value to make sure that it is
disabled by default. (First supported in 3.1.0.)

RSYNC_RSH
The RSYNC_RSH environment variable allows you to override the default shell used as the transport for rsync. Command line options are
permitted after the command name, just as in the -e option.

RSYNC_PROXY
The RSYNC_PROXY environment variable allows you to redirect your rsync client to use a web proxy when connecting to a rsync daemon. You
should set RSYNC_PROXY to a hostname:port pair.

RSYNC_PASSWORD
Setting RSYNC_PASSWORD to the required password allows you to run authenticated rsync connections to an rsync daemon without user interâАР
vention. Note that this does not supply a password to a remote shell transport such as ssh; to learn how to do that, consult the remote
shell's documentation.

USER or LOGNAME
The USER or LOGNAME environment variables are used to determine the default username sent to an rsync daemon. If neither is set, the
username defaults to "nobody".

HOME The HOME environment variable is used to find the user's default .cvsignore file.

FILES

/etc/rsyncd.conf or rsyncd.conf

SEE ALSO

rsync-ssl(1), rsyncd.conf(5)

BUGS

times are transferred as *nix time_t values

When transferring to FAT filesystems rsync may re-sync unmodified files. See the comments on the –modify-window option.

file permissions, devices, etc. are transferred as native numerical values

see also the comments on the –delete option

Please report bugs! See the web site at https://rsync.samba.org/.

VERSION

This man page is current for version 3.2.3 of rsync.

INTERNAL OPTIONS

       The  options  --server and --sender are used internally by rsync, and should never be typed by a user under normal circumstances.  Some awareness
       of these options may be needed in certain scenarios, such as when setting up a login that can only run an rsync command.  For instance, the  supâАР
       port directory of the rsync distribution has an example script named rrsync (for restricted rsync) that can be used with a restricted ssh login.

CREDITS

rsync is distributed under the GNU General Public License. See the file COPYING for details.

A web site is available at https://rsync.samba.org/. The site includes an FAQ-O-Matic which may cover questions unanswered by this manual page.

We would be delighted to hear from you if you like this program. Please contact the mailing-list at rsync@lists.samba.org.

This program uses the excellent zlib compression library written by Jean-loup Gailly and Mark Adler.

THANKS

       Special  thanks go out to: John Van Essen, Matt McCutchen, Wesley W. Terpstra, David Dykstra, Jos Backus, Sebastian Krahmer, Martin Pool, and our
       gone-but-not-forgotten compadre, J.W. Schultz.

       Thanks also to Richard Brent, Brendan Mackay, Bill Waite, Stephen Rothwell and David Bell.  I've probably missed some people, my apologies  if  I
       have.

AUTHOR

       rsync  was  originally  written  by  Andrew Tridgell and Paul Mackerras.  Many people have later contributed to it. It is currently maintained by
       Wayne Davison.

       Mailing lists for support and development are available at https://lists.samba.org/.

rsync 3.2.3                                                            06 Aug 2020                                                              rsync(1)

Linux manpage

manpage top

TOP(1) User Commands TOP(1)

NAME

top – display Linux processes

SYNOPSIS

top -hv|-bcEeHiOSs1 -d secs -n max -u|U user -p pids -o field -w [cols]

The traditional switches `-‘ and whitespace are optional.

DESCRIPTION

       The  top program provides a dynamic real-time view of a running system.  It can display system summary information as well as a list of processes
       or threads currently being managed by the Linux kernel.  The types of system  summary  information  shown  and  the  types,  order  and  size  of
       information displayed for processes are all user configurable and that configuration can be made persistent across restarts.

       The  program  provides  a  limited  interactive  interface  for  process  manipulation  as  well  as a much more extensive interface for personal
       configuration  --  encompassing every aspect of its operation.  And while top is referred to throughout this document, you are free to  name  the
       program  anything  you  wish.   That  new  name,  possibly  an alias, will then be reflected on top's display and used when reading and writing a
       configuration file.

OVERVIEW

Documentation

The remaining Table of Contents

           OVERVIEW
              Operation
              Linux Memory Types
           1. COMMAND-LINE Options
           2. SUMMARY Display
              a. UPTIME and LOAD Averages
              b. TASK and CPU States
              c. MEMORY Usage
           3. FIELDS / Columns Display
              a. DESCRIPTIONS of Fields
              b. MANAGING Fields
           4. INTERACTIVE Commands
              a. GLOBAL Commands
              b. SUMMARY AREA Commands
              c. TASK AREA Commands
                 1. Appearance
                 2. Content
                 3. Size
                 4. Sorting
              d. COLOR Mapping
           5. ALTERNATE-DISPLAY Provisions
              a. WINDOWS Overview
              b. COMMANDS for Windows
              c. SCROLLING a Window
              d. SEARCHING in a Window
              e. FILTERING in a Window
           6. FILES
              a. PERSONAL Configuration File
              b. ADDING INSPECT Entries
              c. SYSTEM Configuration File
              d. SYSTEM Restrictions File
           7. STUPID TRICKS Sampler
              a. Kernel Magic
              b. Bouncing Windows
              c. The Big Bird Window
              d. The Ol' Switcheroo
           8. BUGS, 9. SEE Also

Operation

When operating top, the two most important keys are the help (h or ?) key and quit (`q') key. Alternatively, you could simply use the
traditional interrupt key (^C) when you're done.

When started for the first time, you'll be presented with these traditional elements on the main top screen: 1) Summary Area; 2) Fields/Columns
Header; 3) Task Area. Each of these will be explored in the sections that follow. There is also an Input/Message line between the Summary Area
and Columns Header which needs no further explanation.

The main top screen is generally quite adaptive to changes in terminal dimensions under X-Windows. Other top screens may be less so, especially
those with static text. It ultimately depends, however, on your particular window manager and terminal emulator. There may be occasions when
their view of terminal size and current contents differs from top's view, which is always based on operating system calls.

Following any re-size operation, if a top screen is corrupted, appears incomplete or disordered, simply typing something innocuous like a
punctuation character or cursor motion key will usually restore it. In extreme cases, the following sequence almost certainly will:
key/cmd objective
^Z suspend top
fg resume top
<Left> force a screen redraw (if necessary)

But if the display is still corrupted, there is one more step you could try. Insert this command after top has been suspended but before
resuming it.
key/cmd objective
reset restore your terminal settings

Note: the width of top's display will be limited to 512 positions. Displaying all fields requires approximately 250 characters. Remaining
screen width is usually allocated to any variable width columns currently visible. The variable width columns, such as COMMAND, are noted in
topic 3a. DESCRIPTIONS of Fields. Actual output width may also be influenced by the -w switch, which is discussed in topic 1. COMMAND-LINE
Options.

Lastly, some of top's screens or functions require the use of cursor motion keys like the standard arrow keys plus the Home, End, PgUp and PgDn
keys. If your terminal or emulator does not provide those keys, the following combinations are accepted as alternatives:
key equivalent-keys
Left alt + h
Down alt + j
Up alt + k
Right alt + l
Home alt + ctrl + h
PgDn alt + ctrl + j
PgUp alt + ctrl + k
End alt + ctrl + l

The Up and Down arrow keys have special significance when prompted for line input terminated with the <Enter> key. Those keys, or their aliases,
can be used to retrieve previous input lines which can then be edited and re-input. And there are four additional keys available with line
oriented input.
key special-significance
Up recall older strings for re-editing
Down recall newer strings or erase entire line
Insert toggle between insert and overtype modes
Delete character removed at cursor, moving others left
Home jump to beginning of input line
End jump to end of input line

Linux Memory Types

For our purposes there are three types of memory, and one is optional. First is physical memory, a limited resource where code and data must
reside when executed or referenced. Next is the optional swap file, where modified (dirty) memory can be saved and later retrieved if too many
demands are made on physical memory. Lastly we have virtual memory, a nearly unlimited resource serving the following goals:

1. abstraction, free from physical memory addresses/limits
2. isolation, every process in a separate address space
3. sharing, a single mapping can serve multiple needs
4. flexibility, assign a virtual address to a file

Regardless of which of these forms memory may take, all are managed as pages (typically 4096 bytes) but expressed by default in top as KiB
(kibibyte). The memory discussed under topic `2c. MEMORY Usage' deals with physical memory and the swap file for the system as a whole. The
memory reviewed in topic `3. FIELDS / Columns Display' embraces all three memory types, but for individual processes.

For each such process, every memory page is restricted to a single quadrant from the table below. Both physical memory and virtual memory can
include any of the four, while the swap file only includes #1 through #3. The memory in quadrant #4, when modified, acts as its own dedicated
swap file.

The following may help in interpreting process level memory values displayed as scalable columns and discussed under topic `3a. DESCRIPTIONS of
Fields'.

%MEM - simply RES divided by total physical memory
CODE - the `pgms' portion of quadrant 3
DATA - the entire quadrant 1 portion of VIRT plus all
explicit mmap file-backed pages of quadrant 3
RES - anything occupying physical memory which, beginning with
Linux-4.5, is the sum of the following three fields:
RSan - quadrant 1 pages, which include any
former quadrant 3 pages if modified
RSfd - quadrant 3 and quadrant 4 pages
RSsh - quadrant 2 pages
RSlk - subset of RES which cannot be swapped out (any quadrant)
SHR - subset of RES (excludes 1, includes all 2 & 4, some 3)
SWAP - potentially any quadrant except 4
USED - simply the sum of RES and SWAP
VIRT - everything in-use and/or reserved (all quadrants)

Note: Even though program images and shared libraries are considered private to a process, they will be accounted for as shared (SHR) by the
kernel.

COMMAND-LINE OptionsThe command-line syntax for top consists of:

-hv|-bcEeHiOSs1 -d secs -n max -u|U user -p pids -o field -w [cols]

The typically mandatory switch (`-‘) and even whitespace are completely optional.

-h | -v :Help/Version
Show library version and the usage prompt, then quit.

-b :Batch-mode operation
Starts top in Batch mode, which could be useful for sending output from top to other programs or to a file. In this mode, top will not
accept input and runs until the iterations limit you've set with the `-n' command-line option or until killed.

-c :Command-line/Program-name toggle
Starts top with the last remembered `c' state reversed. Thus, if top was displaying command lines, now that field will show program names,
and vice versa. See the `c' interactive command for additional information.

-d :Delay-time interval as: -d ss.t (secs.tenths)
Specifies the delay between screen updates, and overrides the corresponding value in one's personal configuration file or the startup
default. Later this can be changed with the `d' or `s' interactive commands.

Fractional seconds are honored, but a negative number is not allowed. In all cases, however, such changes are prohibited if top is running
in Secure mode, except for root (unless the `s' command-line option was used). For additional information on Secure mode see topic 6d.
SYSTEM Restrictions File.

-e :Enforce-Task-Memory-Scaling as: -e k | m | g | t | p
Instructs top to force task area memory to be scaled as:
k - kibibytes
m - mebibytes
g - gibibytes
t - tebibytes
p - pebibytes

Later this can be changed with the `e' command toggle.

-E :Enforce-Summary-Memory-Scaling as: -E k | m | g | t | p | e
Instructs top to force summary area memory to be scaled as:
k - kibibytes
m - mebibytes
g - gibibytes
t - tebibytes
p - pebibytes
e - exbibytes

Later this can be changed with the `E' command toggle.

-H :Threads-mode operation
Instructs top to display individual threads. Without this command-line option a summation of all threads in each process is shown. Later
this can be changed with the `H' interactive command.

-i :Idle-process toggle
Starts top with the last remembered `i' state reversed. When this toggle is Off, tasks that have not used any CPU since the last update
will not be displayed. For additional information regarding this toggle see topic 4c. TASK AREA Commands, SIZE.

-n :Number-of-iterations limit as: -n number
Specifies the maximum number of iterations, or frames, top should produce before ending.

-o :Override-sort-field as: -o fieldname
Specifies the name of the field on which tasks will be sorted, independent of what is reflected in the configuration file. You can prepend
a `+' or `-' to the field name to also override the sort direction. A leading `+' will force sorting high to low, whereas a `-' will ensure
a low to high ordering.

This option exists primarily to support automated/scripted batch mode operation.

-O :Output-field-names
This option acts as a form of help for the above -o option. It will cause top to print each of the available field names on a separate
line, then quit. Such names are subject to NLS (National Language Support) translation.

-p :Monitor-PIDs mode as: -pN1 -pN2 ... or -pN1,N2,N3 ...
Monitor only processes with specified process IDs. This option can be given up to 20 times, or you can provide a comma delimited list with
up to 20 pids. Co-mingling both approaches is permitted.

A pid value of zero will be treated as the process id of the top program itself once it is running.

This is a command-line option only and should you wish to return to normal operation, it is not necessary to quit and restart top -- just
issue any of these interactive commands: `=', `u' or `U'.

The `p', `u' and `U' command-line options are mutually exclusive.

-s :Secure-mode operation
Starts top with secure mode forced, even for root. This mode is far better controlled through a system configuration file (see topic 6.
FILES).

-S :Cumulative-time toggle
Starts top with the last remembered `S' state reversed. When Cumulative time mode is On, each process is listed with the cpu time that it
and its dead children have used. See the `S' interactive command for additional information regarding this mode.

-u | -U :User-filter-mode as: -u | -U number or name
Display only processes with a user id or user name matching that given. The `-u' option matches on effective user whereas the `-U' option
matches on any user (real, effective, saved, or filesystem).

Prepending an exclamation point (`!') to the user id or name instructs top to display only processes with users not matching the one
provided.

The `p', `u' and `U' command-line options are mutually exclusive.

-w :Output-width-override as: -w [ number ]
In Batch mode, when used without an argument top will format output using the COLUMNS= and LINES= environment variables, if set. Otherwise,
width will be fixed at the maximum 512 columns. With an argument, output width can be decreased or increased (up to 512) but the number of
rows is considered unlimited.

In normal display mode, when used without an argument top will attempt to format output using the COLUMNS= and LINES= environment variables,
if set. With an argument, output width can only be decreased, not increased. Whether using environment variables or an argument with -w,
when not in Batch mode actual terminal dimensions can never be exceeded.

Note: Without the use of this command-line option, output width is always based on the terminal at which top was invoked whether or not in
Batch mode.

-1 :Single/Separate-Cpu-States toggle
Starts top with the last remembered Cpu States portion of the summary area reversed. Either all cpu information will be displayed in a
single line or each cpu will be displayed separately, depending on the state of the NUMA Node command toggle ('2').

See the `1' and '2' interactive commands for additional information.

2. SUMMARY Display

       Each  of the following three areas are individually controlled through one or more interactive commands.  See topic 4b. SUMMARY AREA Commands for
       additional information regarding these provisions.

2a. UPTIME and LOAD Averages

       This portion consists of a single line containing:
           program or window name, depending on display mode
           current time and length of time since last boot
           total number of users
           system load avg over the last 1, 5 and 15 minutes

2b. TASK and CPU States

This portion consists of a minimum of two lines. In an SMP environment, additional lines can reflect individual CPU state percentages.

       Line 1 shows total tasks or threads, depending on the state of the Threads-mode toggle.  That total is further classified as:
           running; sleeping; stopped; zombie

       Line 2 shows CPU state percentages based on the interval since the last refresh.

       As a default, percentages for these individual categories are displayed.  Where two labels are shown below, those for more recent kernel versions
       are shown first.
           us, user    : time running un-niced user processes
           sy, system  : time running kernel processes
           ni, nice    : time running niced user processes
           id, idle    : time spent in the kernel idle handler
           wa, IO-wait : time waiting for I/O completion
           hi : time spent servicing hardware interrupts
           si : time spent servicing software interrupts
           st : time stolen from this vm by the hypervisor

       In the alternate cpu states display modes, beyond the first tasks/threads line, an abbreviated summary is shown consisting of these elements:
                      a    b     c    d
           %Cpu(s):  75.0/25.0  100[ ...

       Where:  a)  is the `user' (us + ni) percentage; b) is the `system' (sy + hi + si) percentage; c) is the total; and d) is one of two visual graphs
       of those representations.  See topic 4b. SUMMARY AREA Commands and the `t' command for additional information on that special 4-way toggle.

2c. MEMORY Usage

       This portion consists of two lines which may express values in kibibytes (KiB) through exbibytes (EiB) depending on the scaling  factor  enforced
       with the `E' interactive command.

       As a default, Line 1 reflects physical memory, classified as:
           total, free, used and buff/cache

       Line 2 reflects mostly virtual memory, classified as:
           total, free, used and avail (which is physical memory)

       The avail number on line 2 is an estimation of physical memory available for starting new applications, without swapping.  Unlike the free field,
       it attempts to account for readily reclaimable page cache and memory slabs.  It is available  on  kernels  3.14,  emulated  on  kernels  2.6.27+,
       otherwise the same as free.

       In the alternate memory display modes, two abbreviated summary lines are shown consisting of these elements:
                      a    b          c
           GiB Mem : 18.7/15.738   [ ...
           GiB Swap:  0.0/7.999    [ ...

       Where: a) is the percentage used; b) is the total available; and c) is one of two visual graphs of those representations.

       In  the  case  of  physical memory, the percentage represents the total minus the estimated avail noted above.  The `Mem' graph itself is divided
       between used and any remaining memory not otherwise accounted for by avail.  See topic  4b.  SUMMARY  AREA  Commands  and  the  `m'  command  for
       additional information on that special 4-way toggle.

       This table may help in interpreting the scaled values displayed:
           KiB = kibibyte = 1024 bytes
           MiB = mebibyte = 1024 KiB = 1,048,576 bytes
           GiB = gibibyte = 1024 MiB = 1,073,741,824 bytes
           TiB = tebibyte = 1024 GiB = 1,099,511,627,776 bytes
           PiB = pebibyte = 1024 TiB = 1,125,899,906,842,624 bytes
           EiB = exbibyte = 1024 PiB = 1,152,921,504,606,846,976 bytes

3. FIELDS / Columns

3a. DESCRIPTIONS of Fields

Listed below are top's available process fields (columns). They are shown in strict ascii alphabetical order. You may customize their position
and whether or not they are displayable with the `f' or `F' (Fields Management) interactive commands.

Any field is selectable as the sort field, and you control whether they are sorted high-to-low or low-to-high. For additional information on
sort provisions see topic 4c. TASK AREA Commands, SORTING.

The fields related to physical memory or virtual memory reference `(KiB)' which is the unsuffixed display mode. Such fields may, however, be
scaled from KiB through PiB. That scaling is influenced via the `e' interactive command or established for startup through a build option.

1. %CPU -- CPU Usage
The task's share of the elapsed CPU time since the last screen update, expressed as a percentage of total CPU time.

In a true SMP environment, if a process is multi-threaded and top is not operating in Threads mode, amounts greater than 100% may be
reported. You toggle Threads mode with the `H' interactive command.

Also for multi-processor environments, if Irix mode is Off, top will operate in Solaris mode where a task's cpu usage will be divided by the
total number of CPUs. You toggle Irix/Solaris modes with the `I' interactive command.

Note: When running in forest view mode (`V') with children collapsed (`v'), this field will also include the CPU time of those unseen
children. See topic 4c. TASK AREA Commands, CONTENT for more information regarding the `V' and `v' toggles.

2. %MEM -- Memory Usage (RES)
A task's currently resident share of available physical memory.

See `OVERVIEW, Linux Memory Types' for additional details.

3. CGNAME -- Control Group Name
The name of the control group to which a process belongs, or `-' if not applicable for that process.

This will typically be the last entry in the full list of control groups as shown under the next heading (CGROUPS). And as is true there,
this field is also variable width.

4. CGROUPS -- Control Groups
The names of the control group(s) to which a process belongs, or `-' if not applicable for that process.

Control Groups provide for allocating resources (cpu, memory, network bandwidth, etc.) among installation-defined groups of processes. They
enable fine-grained control over allocating, denying, prioritizing, managing and monitoring those resources.

Many different hierarchies of cgroups can exist simultaneously on a system and each hierarchy is attached to one or more subsystems. A
subsystem represents a single resource.

Note: The CGROUPS field, unlike most columns, is not fixed-width. When displayed, it plus any other variable width columns will be allocated
all remaining screen width (up to the maximum 512 characters). Even so, such variable width fields could still suffer truncation. See topic
5c. SCROLLING a Window for additional information on accessing any truncated data.

5. CODE -- Code Size (KiB)
The amount of physical memory currently devoted to executable code, also known as the Text Resident Set size or TRS.

See `OVERVIEW, Linux Memory Types' for additional details.

6. COMMAND -- Command Name or Command Line
Display the command line used to start a task or the name of the associated program. You toggle between command line and name with `c',
which is both a command-line option and an interactive command.

When you've chosen to display command lines, processes without a command line (like kernel threads) will be shown with only the program name
in brackets, as in this example:
[kthreadd]

This field may also be impacted by the forest view display mode. See the `V' interactive command for additional information regarding that
mode.

Note: The COMMAND field, unlike most columns, is not fixed-width. When displayed, it plus any other variable width columns will be allocated
all remaining screen width (up to the maximum 512 characters). Even so, such variable width fields could still suffer truncation. This is
especially true for this field when command lines are being displayed (the `c' interactive command.) See topic 5c. SCROLLING a Window for
additional information on accessing any truncated data.

7. DATA -- Data + Stack Size (KiB)
The amount of private memory reserved by a process. It is also known as the Data Resident Set or DRS. Such memory may not yet be mapped to
physical memory (RES) but will always be included in the virtual memory (VIRT) amount.

See `OVERVIEW, Linux Memory Types' for additional details.

8. ENVIRON -- Environment variables
Display all of the environment variables, if any, as seen by the respective processes. These variables will be displayed in their raw native
order, not the sorted order you are accustomed to seeing with an unqualified `set'.

Note: The ENVIRON field, unlike most columns, is not fixed-width. When displayed, it plus any other variable width columns will be allocated
all remaining screen width (up to the maximum 512 characters). Even so, such variable width fields could still suffer truncation. This is
especially true for this field. See topic 5c. SCROLLING a Window for additional information on accessing any truncated data.

9. Flags -- Task Flags
This column represents the task's current scheduling flags which are expressed in hexadecimal notation and with zeros suppressed. These
flags are officially documented in <linux/sched.h>.

10. GID -- Group Id
The effective group ID.

11. GROUP -- Group Name
The effective group name.

12. LXC -- Lxc Container Name
The name of the lxc container within which a task is running. If a process is not running inside a container, a dash (`-') will be shown.

13. NI -- Nice Value
The nice value of the task. A negative nice value means higher priority, whereas a positive nice value means lower priority. Zero in this
field simply means priority will not be adjusted in determining a task's dispatch-ability.

14. NU -- Last known NUMA node
A number representing the NUMA node associated with the last used processor (`P'). When -1 is displayed it means that NUMA information is
not available.

See the `'2' and `3' interactive commands for additional NUMA provisions affecting the summary area.

15. OOMa -- Out of Memory Adjustment Factor
The value, ranging from -1000 to +1000, added to the current out of memory score (OOMs) which is then used to determine which task to kill
when memory is exhausted.

16. OOMs -- Out of Memory Score
The value, ranging from 0 to +1000, used to select task(s) to kill when memory is exhausted. Zero translates to `never kill' whereas 1000
means `always kill'.

17. P -- Last used CPU (SMP)
A number representing the last used processor. In a true SMP environment this will likely change frequently since the kernel intentionally
uses weak affinity. Also, the very act of running top may break this weak affinity and cause more processes to change CPUs more often
(because of the extra demand for cpu time).

18. PGRP -- Process Group Id
Every process is member of a unique process group which is used for distribution of signals and by terminals to arbitrate requests for their
input and output. When a process is created (forked), it becomes a member of the process group of its parent. By convention, this value
equals the process ID (see PID) of the first member of a process group, called the process group leader.

19. PID -- Process Id
The task's unique process ID, which periodically wraps, though never restarting at zero. In kernel terms, it is a dispatchable entity
defined by a task_struct.

This value may also be used as: a process group ID (see PGRP); a session ID for the session leader (see SID); a thread group ID for the
thread group leader (see TGID); and a TTY process group ID for the process group leader (see TPGID).

20. PPID -- Parent Process Id
The process ID (pid) of a task's parent.

21. PR -- Priority
The scheduling priority of the task. If you see `rt' in this field, it means the task is running under real time scheduling priority.

Under linux, real time priority is somewhat misleading since traditionally the operating itself was not preemptible. And while the 2.6
kernel can be made mostly preemptible, it is not always so.

22. RES -- Resident Memory Size (KiB)
A subset of the virtual address space (VIRT) representing the non-swapped physical memory a task is currently using. It is also the sum of
the RSan, RSfd and RSsh fields.

It can include private anonymous pages, private pages mapped to files (including program images and shared libraries) plus shared anonymous
pages. All such memory is backed by the swap file represented separately under SWAP.

Lastly, this field may also include shared file-backed pages which, when modified, act as a dedicated swap file and thus will never impact
SWAP.

See `OVERVIEW, Linux Memory Types' for additional details.

23. RSan -- Resident Anonymous Memory Size (KiB)
A subset of resident memory (RES) representing private pages not mapped to a file.

24. RSfd -- Resident File-Backed Memory Size (KiB)
A subset of resident memory (RES) representing the implicitly shared pages supporting program images and shared libraries. It also includes
explicit file mappings, both private and shared.

25. RSlk -- Resident Locked Memory Size (KiB)
A subset of resident memory (RES) which cannot be swapped out.

26. RSsh -- Resident Shared Memory Size (KiB)
A subset of resident memory (RES) representing the explicitly shared anonymous shm*/mmap pages.

27. RUID -- Real User Id
The real user ID.

28. RUSER -- Real User Name
The real user name.

29. S -- Process Status
The status of the task which can be one of:
D = uninterruptible sleep
I = idle
R = running
S = sleeping
T = stopped by job control signal
t = stopped by debugger during trace
Z = zombie

Tasks shown as running should be more properly thought of as ready to run -- their task_struct is simply represented on the Linux run-
queue. Even without a true SMP machine, you may see numerous tasks in this state depending on top's delay interval and nice value.

30. SHR -- Shared Memory Size (KiB)
A subset of resident memory (RES) that may be used by other processes. It will include shared anonymous pages and shared file-backed pages.
It also includes private pages mapped to files representing program images and shared libraries.

See `OVERVIEW, Linux Memory Types' for additional details.

31. SID -- Session Id
A session is a collection of process groups (see PGRP), usually established by the login shell. A newly forked process joins the session of
its creator. By convention, this value equals the process ID (see PID) of the first member of the session, called the session leader, which
is usually the login shell.

32. SUID -- Saved User Id
The saved user ID.

33. SUPGIDS -- Supplementary Group IDs
The IDs of any supplementary group(s) established at login or inherited from a task's parent. They are displayed in a comma delimited list.

Note: The SUPGIDS field, unlike most columns, is not fixed-width. When displayed, it plus any other variable width columns will be allocated
all remaining screen width (up to the maximum 512 characters). Even so, such variable width fields could still suffer truncation. See topic
5c. SCROLLING a Window for additional information on accessing any truncated data.

34. SUPGRPS -- Supplementary Group Names
The names of any supplementary group(s) established at login or inherited from a task's parent. They are displayed in a comma delimited
list.

Note: The SUPGRPS field, unlike most columns, is not fixed-width. When displayed, it plus any other variable width columns will be allocated
all remaining screen width (up to the maximum 512 characters). Even so, such variable width fields could still suffer truncation. See topic
5c. SCROLLING a Window for additional information on accessing any truncated data.

35. SUSER -- Saved User Name
The saved user name.

36. SWAP -- Swapped Size (KiB)
The formerly resident portion of a task's address space written to the swap file when physical memory becomes over committed.

See `OVERVIEW, Linux Memory Types' for additional details.

37. TGID -- Thread Group Id
The ID of the thread group to which a task belongs. It is the PID of the thread group leader. In kernel terms, it represents those tasks
that share an mm_struct.

38. TIME -- CPU Time
Total CPU time the task has used since it started. When Cumulative mode is On, each process is listed with the cpu time that it and its dead
children have used. You toggle Cumulative mode with `S', which is both a command-line option and an interactive command. See the `S'
interactive command for additional information regarding this mode.

39. TIME+ -- CPU Time, hundredths
The same as TIME, but reflecting more granularity through hundredths of a second.

40. TPGID -- Tty Process Group Id
The process group ID of the foreground process for the connected tty, or -1 if a process is not connected to a terminal. By convention, this
value equals the process ID (see PID) of the process group leader (see PGRP).

41. TTY -- Controlling Tty
The name of the controlling terminal. This is usually the device (serial port, pty, etc.) from which the process was started, and which it
uses for input or output. However, a task need not be associated with a terminal, in which case you'll see `?' displayed.

42. UID -- User Id
The effective user ID of the task's owner.

43. USED -- Memory in Use (KiB)
This field represents the non-swapped physical memory a task is using (RES) plus the swapped out portion of its address space (SWAP).

See `OVERVIEW, Linux Memory Types' for additional details.

44. USER -- User Name
The effective user name of the task's owner.

45. VIRT -- Virtual Memory Size (KiB)
The total amount of virtual memory used by the task. It includes all code, data and shared libraries plus pages that have been swapped out
and pages that have been mapped but not used.

See `OVERVIEW, Linux Memory Types' for additional details.

46. WCHAN -- Sleeping in Function
This field will show the name of the kernel function in which the task is currently sleeping. Running tasks will display a dash (`-') in
this column.

47. nDRT -- Dirty Pages Count
The number of pages that have been modified since they were last written to auxiliary storage. Dirty pages must be written to auxiliary
storage before the corresponding physical memory location can be used for some other virtual page.

This field was deprecated with linux 2.6 and is always zero.

48. nMaj -- Major Page Fault Count
The number of major page faults that have occurred for a task. A page fault occurs when a process attempts to read from or write to a
virtual page that is not currently present in its address space. A major page fault is when auxiliary storage access is involved in making
that page available.

49. nMin -- Minor Page Fault count
The number of minor page faults that have occurred for a task. A page fault occurs when a process attempts to read from or write to a
virtual page that is not currently present in its address space. A minor page fault does not involve auxiliary storage access in making that
page available.

50. nTH -- Number of Threads
The number of threads associated with a process.

51. nsIPC -- IPC namespace
The Inode of the namespace used to isolate interprocess communication (IPC) resources such as System V IPC objects and POSIX message queues.

52. nsMNT -- MNT namespace
The Inode of the namespace used to isolate filesystem mount points thus offering different views of the filesystem hierarchy.

53. nsNET -- NET namespace
The Inode of the namespace used to isolate resources such as network devices, IP addresses, IP routing, port numbers, etc.

54. nsPID -- PID namespace
The Inode of the namespace used to isolate process ID numbers meaning they need not remain unique. Thus, each such namespace could have its
own `init/systemd' (PID #1) to manage various initialization tasks and reap orphaned child processes.

55. nsUSER -- USER namespace
The Inode of the namespace used to isolate the user and group ID numbers. Thus, a process could have a normal unprivileged user ID outside a
user namespace while having a user ID of 0, with full root privileges, inside that namespace.

56. nsUTS -- UTS namespace
The Inode of the namespace used to isolate hostname and NIS domain name. UTS simply means "UNIX Time-sharing System".

57. vMj -- Major Page Fault Count Delta
The number of major page faults that have occurred since the last update (see nMaj).

58. vMn -- Minor Page Fault Count Delta
The number of minor page faults that have occurred since the last update (see nMin).

3b. MANAGING Fields

After pressing the interactive command `f' or `F' (Fields Management) you will be presented with a screen showing: 1) the `current' window name;
2) the designated sort field; 3) all fields in their current order along with descriptions. Entries marked with an asterisk are the currently
displayed fields, screen width permitting.

â€¢ As the on screen instructions indicate, you navigate among the fields with the Up and Down arrow keys. The PgUp, PgDn, Home and End keys
can also be used to quickly reach the first or last available field.

â€¢ The Right arrow key selects a field for repositioning and the Left arrow key or the <Enter> key commits that field's placement.

â€¢ The `d' key or the <Space> bar toggles a field's display status, and thus the presence or absence of the asterisk.

â€¢ The `s' key designates a field as the sort field. See topic 4c. TASK AREA Commands, SORTING for additional information regarding your
selection of a sort field.

â€¢ The `a' and `w' keys can be used to cycle through all available windows and the `q' or <Esc> keys exit Fields Management.

The Fields Management screen can also be used to change the `current' window/field group in either full-screen mode or alternate-display mode.
Whatever was targeted when `q' or <Esc> was pressed will be made current as you return to the top display. See topic 5. ALTERNATE-DISPLAY
Provisions and the `g' interactive command for insight into `current' windows and field groups.

Note: Any window that has been scrolled horizontally will be reset if any field changes are made via the Fields Management screen. Any vertical
scrolled position, however, will not be affected. See topic 5c. SCROLLING a Window for additional information regarding vertical and horizontal
scrolling.

4. INTERACTIVE Commands

       Listed  below is a brief index of commands within categories.  Some commands appear more than once  --  their meaning or scope may vary depending
       on the context in which they are issued.

         4a. Global-Commands
               <Ent/Sp> ?, =, 0,
               A, B, d, E, e, g, h, H, I, k, q, r, s, W, X, Y, Z
         4b. Summary-Area-Commands
               C, l, t, m, 1, 2, 3, 4, !
         4c. Task-Area-Commands
               Appearance:  b, J, j, x, y, z
               Content:     c, f, F, o, O, S, u, U, V, v
               Size:        #, i, n
               Sorting:     <, >, f, F, R
         4d. Color-Mapping
               <Ret>, a, B, b, H, M, q, S, T, w, z, 0 - 7
         5b. Commands-for-Windows
               -, _, =, +, A, a, g, G, w
         5c. Scrolling-a-Window
               C, Up, Dn, Left, Right, PgUp, PgDn, Home, End
         5d. Searching-in-a-Window
               L, &

4a. GLOBAL Commands

The global interactive commands are always available in both full-screen mode and alternate-display mode. However, some of these interactive
commands are not available when running in Secure mode.

If you wish to know in advance whether or not your top has been secured, simply ask for help and view the system summary on the second line.

<Enter> or <Space> :Refresh-Display
These commands awaken top and following receipt of any input the entire display will be repainted. They also force an update of any
hotplugged cpu or physical memory changes.

Use either of these keys if you have a large delay interval and wish to see current status,

? | h :Help
There are two help levels available. The first will provide a reminder of all the basic interactive commands. If top is secured, that
screen will be abbreviated.

Typing `h' or `?' on that help screen will take you to help for those interactive commands applicable to alternate-display mode.

= :Exit-Display-Limits
Removes restrictions on what is shown. This command will reverse any `i' (idle tasks), `n' (max tasks) and `v' (hide children) commands
that might be active. It also provides for an exit from PID monitoring, User filtering, Other filtering, Locate processing and Combine
Cpus mode.

Additionally, if the window has been scrolled it will be reset with this command.

0 :Zero-Suppress toggle
This command determines whether zeros are shown or suppressed for many of the fields in a task window. Fields like UID, GID, NI, PR or P
are not affected by this toggle.

A :Alternate-Display-Mode toggle
This command will switch between full-screen mode and alternate-display mode. See topic 5. ALTERNATE-DISPLAY Provisions and the `g'
interactive command for insight into `current' windows and field groups.

B :Bold-Disable/Enable toggle
This command will influence use of the bold terminfo capability and alters both the summary area and task area for the `current' window.
While it is intended primarily for use with dumb terminals, it can be applied anytime.

Note: When this toggle is On and top is operating in monochrome mode, the entire display will appear as normal text. Thus, unless the `x'
and/or `y' toggles are using reverse for emphasis, there will be no visual confirmation that they are even on.

* d | s :Change-Delay-Time-interval
You will be prompted to enter the delay time, in seconds, between display updates.

Fractional seconds are honored, but a negative number is not allowed. Entering 0 causes (nearly) continuous updates, with an
unsatisfactory display as the system and tty driver try to keep up with top's demands. The delay value is inversely proportional to
system loading, so set it with care.

If at any time you wish to know the current delay time, simply ask for help and view the system summary on the second line.

E :Enforce-Summary-Memory-Scale in Summary Area
With this command you can cycle through the available summary area memory scaling which ranges from KiB (kibibytes or 1,024 bytes) through
EiB (exbibytes or 1,152,921,504,606,846,976 bytes).

If you see a `+' between a displayed number and the following label, it means that top was forced to truncate some portion of that number.
By raising the scaling factor, such truncation can be avoided.

e :Enforce-Task-Memory-Scale in Task Area
With this command you can cycle through the available task area memory scaling which ranges from KiB (kibibytes or 1,024 bytes) through
PiB (pebibytes or 1,125,899,906,842,624 bytes).

While top will try to honor the selected target range, additional scaling might still be necessary in order to accommodate current values.
If you wish to see a more homogeneous result in the memory columns, raising the scaling range will usually accomplish that goal. Raising
it too high, however, is likely to produce an all zero result which cannot be suppressed with the `0' interactive command.

g :Choose-Another-Window/Field-Group
You will be prompted to enter a number between 1 and 4 designating the field group which should be made the `current' window. You will
soon grow comfortable with these 4 windows, especially after experimenting with alternate-display mode.

H :Threads-mode toggle
When this toggle is On, individual threads will be displayed for all processes in all visible task windows. Otherwise, top displays a
summation of all threads in each process.

I :Irix/Solaris-Mode toggle
When operating in Solaris mode (`I' toggled Off), a task's cpu usage will be divided by the total number of CPUs. After issuing this
command, you'll be told the new state of this toggle.

* k :Kill-a-task
You will be prompted for a PID and then the signal to send.

Entering no PID or a negative number will be interpreted as the default shown in the prompt (the first task displayed). A PID value of
zero means the top program itself.

The default signal, as reflected in the prompt, is SIGTERM. However, you can send any signal, via number or name.

If you wish to abort the kill process, do one of the following depending on your progress:
1) at the pid prompt, type an invalid number
2) at the signal prompt, type 0 (or any invalid signal)
3) at any prompt, type <Esc>

q :Quit

* r :Renice-a-Task
You will be prompted for a PID and then the value to nice it to.

Entering no PID or a negative number will be interpreted as the default shown in the prompt (the first task displayed). A PID value of
zero means the top program itself.

A positive nice value will cause a process to lose priority. Conversely, a negative nice value will cause a process to be viewed more
favorably by the kernel. As a general rule, ordinary users can only increase the nice value and are prevented from lowering it.

If you wish to abort the renice process, do one of the following depending on your progress:
1) at the pid prompt, type an invalid number
2) at the nice prompt, type <Enter> with no input
3) at any prompt, type <Esc>

W :Write-the-Configuration-File
This will save all of your options and toggles plus the current display mode and delay time. By issuing this command just before quitting
top, you will be able restart later in exactly that same state.

X :Extra-Fixed-Width
Some fields are fixed width and not scalable. As such, they are subject to truncation which would be indicated by a `+' in the last
position.

This interactive command can be used to alter the widths of the following fields:

field default field default field default
GID 5 GROUP 8 WCHAN 10
RUID 5 LXC 8 nsIPC 10
SUID 5 RUSER 8 nsMNT 10
UID 5 SUSER 8 nsNET 10
TTY 8 nsPID 10
USER 8 nsUSER 10
nsUTS 10

You will be prompted for the amount to be added to the default widths shown above. Entering zero forces a return to those defaults.

If you enter a negative number, top will automatically increase the column size as needed until there is no more truncated data. You can
accelerate this process by reducing the delay interval or holding down the <Space> bar.

Note: Whether explicitly or automatically increased, the widths for these fields are never decreased by top. To narrow them you must
specify a smaller number or restore the defaults.

Y :Inspect-Other-Output
After issuing the `Y' interactive command, you will be prompted for a target PID. Typing a value or accepting the default results in a
separate screen. That screen can be used to view a variety of files or piped command output while the normal top iterative display is
paused.

Note: This interactive command is only fully realized when supporting entries have been manually added to the end of the top configuration
file. For details on creating those entries, see topic 6b. ADDING INSPECT Entries.

Most of the keys used to navigate the Inspect feature are reflected in its header prologue. There are, however, additional keys available
once you have selected a particular file or command. They are familiar to anyone who has used the pager `less' and are summarized here
for future reference.

key function
= alternate status-line, file or pipeline
/ find, equivalent to `L' locate
n find next, equivalent to `&' locate next
<Space> scroll down, equivalent to <PgDn>
b scroll up, equivalent to <PgUp>
g first line, equivalent to <Home>
G last line, equivalent to <End>

Z :Change-Color-Mapping
This key will take you to a separate screen where you can change the colors for the `current' window, or for all windows. For details
regarding this interactive command see topic 4d. COLOR Mapping.

The commands shown with an asterisk (`') are not available in Secure mode, nor will they be shown on the level-1 help screen.

4b. SUMMARY AREA Commands

The summary area interactive commands are always available in both full-screen mode and alternate-display mode. They affect the beginning lines
of your display and will determine the position of messages and prompts.

These commands always impact just the `current' window/field group. See topic 5. ALTERNATE-DISPLAY Provisions and the `g' interactive command
for insight into `current' windows and field groups.

C :Show-scroll-coordinates toggle
Toggle an informational message which is displayed whenever the message line is not otherwise being used. For additional information see
topic 5c. SCROLLING a Window.

l :Load-Average/Uptime toggle
This is also the line containing the program name (possibly an alias) when operating in full-screen mode or the `current' window name when
operating in alternate-display mode.

t :Task/Cpu-States toggle
This command affects from 2 to many summary area lines, depending on the state of the `1', `2' or `3' command toggles and whether or not
top is running under true SMP.

This portion of the summary area is also influenced by the `H' interactive command toggle, as reflected in the total label which shows
either Tasks or Threads.

This command serves as a 4-way toggle, cycling through these modes:
1. detailed percentages by category
2. abbreviated user/system and total % + bar graph
3. abbreviated user/system and total % + block graph
4. turn off task and cpu states display

When operating in either of the graphic modes, the display becomes much more meaningful when individual CPUs or NUMA nodes are also
displayed. See the the `1', `2' and `3' commands below for additional information.

m :Memory/Swap-Usage toggle
This command affects the two summary area lines dealing with physical and virtual memory.

This command serves as a 4-way toggle, cycling through these modes:
1. detailed percentages by memory type
2. abbreviated % used/total available + bar graph
3. abbreviated % used/total available + block graph
4. turn off memory display

1 :Single/Separate-Cpu-States toggle
This command affects how the `t' command's Cpu States portion is shown. Although this toggle exists primarily to serve massively-parallel
SMP machines, it is not restricted to solely SMP environments.

When you see `%Cpu(s):' in the summary area, the `1' toggle is On and all cpu information is gathered in a single line. Otherwise, each
cpu is displayed separately as: `%Cpu0, %Cpu1, ...' up to available screen height.

2 :NUMA-Nodes/Cpu-Summary toggle
This command toggles between the `1' command cpu summary display (only) or a summary display plus the cpu usage statistics for each NUMA
Node. It is only available if a system has the requisite NUMA support.

3 :Expand-NUMA-Node
You will be invited to enter a number representing a NUMA Node. Thereafter, a node summary plus the statistics for each cpu in that node
will be shown until the `1', `2' or `4' command toggle is pressed. This interactive command is only available if a system has the
requisite NUMA support.

4 :Display-Cpus-Two-Abreast
This command turns the `1' toggle Off for individual cpu display but prints the results two abreast. It requires a terminal with a
minimum width of 80 columns. If a terminal's width is decreased below the minimum while top is running, top reverts to the normal `1'
toggle Off state.

To avoid truncation when displaying detailed cpu statistcs, as opposed to the graphic representations, a minimum width of 165 columns
would be required.

! :Combine-Cpus-Mode
This command toggle is intended for massively parallel SMP environments where, even with the `4' command toggle, not all processors can be
displayed. With each press of `!' the number of additional cpu's combined is doubled thus reducing the total number of cpu lines
displayed.

For example, with the first press of `!' one additional cpu will be combined and displayed as `0-1, 2-3, ...' instead of the normal
`%Cpu0, %Cpu1, %Cpu2, %Cpu3, ...'. With a second `!' command toggle two additional cpus are combined and shown as `0-2, 3-5, ...'. Then
the third '!' press, combining four additional cpus, shows as `0-4, 5-9, ...', etc.

Such progression continues until individual cpus are again displayed and impacts both the `1' and `4' toggles (one or two columns). Use
the `=' command to exit Combine Cpus mode.

Note: If the entire summary area has been toggled Off for any window, you would be left with just the message line. In that way, you will have
maximized available task rows but (temporarily) sacrificed the program name in full-screen mode or the `current' window name when in
alternate-display mode.

4c. TASK AREA Commands

The task area interactive commands are always available in full-screen mode.

The task area interactive commands are never available in alternate-display mode if the `current' window's task display has been toggled Off (see
topic 5. ALTERNATE-DISPLAY Provisions).

APPEARANCE of task window

J :Justify-Numeric-Columns toggle
Alternates between right-justified (the default) and left-justified numeric data. If the numeric data completely fills the available
column, this command toggle may impact the column header only.

j :Justify-Character-Columns toggle
Alternates between left-justified (the default) and right-justified character data. If the character data completely fills the available
column, this command toggle may impact the column header only.

The following commands will also be influenced by the state of the global `B' (bold enable) toggle.

b :Bold/Reverse toggle
This command will impact how the `x' and `y' toggles are displayed. It may also impact the summary area when a bar graph has been
selected for cpu states or memory usage via the `t' or `m' toggles.

x :Column-Highlight toggle
Changes highlighting for the current sort field. If you forget which field is being sorted this command can serve as a quick visual
reminder, providing the sort field is being displayed. The sort field might not be visible because:
1) there is insufficient Screen Width
2) the `f' interactive command turned it Off

Note: Whenever Searching and/or Other Filtering is active in a window, column highlighting is temporarily disabled. See the notes at the
end of topics 5d. SEARCHING and 5e. FILTERING for an explanation why.

y :Row-Highlight toggle
Changes highlighting for "running" tasks. For additional insight into this task state, see topic 3a. DESCRIPTIONS of Fields, the `S'
field (Process Status).

Use of this provision provides important insight into your system's health. The only costs will be a few additional tty escape sequences.

z :Color/Monochrome toggle
Switches the `current' window between your last used color scheme and the older form of black-on-white or white-on-black. This command
will alter both the summary area and task area but does not affect the state of the `x', `y' or `b' toggles.

CONTENT of task window

c :Command-Line/Program-Name toggle
This command will be honored whether or not the COMMAND column is currently visible. Later, should that field come into view, the change
you applied will be seen.

f | F :Fields-Management
These keys display a separate screen where you can change which fields are displayed, their order and also designate the sort field. For
additional information on these interactive commands see topic 3b. MANAGING Fields.

o | O :Other-Filtering
You will be prompted for the selection criteria which then determines which tasks will be shown in the `current' window. Your criteria
can be made case sensitive or case can be ignored. And you determine if top should include or exclude matching tasks.

See topic 5e. FILTERING in a window for details on these and additional related interactive commands.

S :Cumulative-Time-Mode toggle
When Cumulative mode is On, each process is listed with the cpu time that it and its dead children have used.

When Off, programs that fork into many separate tasks will appear less demanding. For programs like `init' or a shell this is appropriate
but for others, like compilers, perhaps not. Experiment with two task windows sharing the same sort field but with different `S' states
and see which representation you prefer.

After issuing this command, you'll be informed of the new state of this toggle. If you wish to know in advance whether or not Cumulative
mode is in effect, simply ask for help and view the window summary on the second line.

u | U :Show-Specific-User-Only
You will be prompted for the uid or name of the user to display. The -u option matches on effective user whereas the -U option matches
on any user (real, effective, saved, or filesystem).

Thereafter, in that task window only matching users will be shown, or possibly no processes will be shown. Prepending an exclamation
point (`!') to the user id or name instructs top to display only processes with users not matching the one provided.

Different task windows can be used to filter different users. Later, if you wish to monitor all users again in the `current' window, re-
issue this command but just press <Enter> at the prompt.

V :Forest-View-Mode toggle
In this mode, processes are reordered according to their parents and the layout of the COMMAND column resembles that of a tree. In forest
view mode it is still possible to toggle between program name and command line (see the `c' interactive command) or between processes and
threads (see the `H' interactive command).

Note: Typing any key affecting the sort order will exit forest view mode in the `current' window. See topic 4c. TASK AREA Commands,
SORTING for information on those keys.

v :Hide/Show-Children toggle
When in forest view mode, this key serves as a toggle to collapse or expand the children of a parent.

The toggle is applied against the first (topmost) process in the `current' window. See topic 5c. SCROLLING a Window for additional
information regarding vertical scrolling.

If the target process has not forked any children, this key has no effect. It also has no effect when not in forest view mode.

SIZE of task window

i :Idle-Process toggle
Displays all tasks or just active tasks. When this toggle is Off, tasks that have not used any CPU since the last update will not be
displayed. However, due to the granularity of the %CPU and TIME+ fields, some processes may still be displayed that appear to have used
no CPU.

If this command is applied to the last task display when in alternate-display mode, then it will not affect the window's size, as all
prior task displays will have already been painted.

n | # :Set-Maximum-Tasks
You will be prompted to enter the number of tasks to display. The lessor of your number and available screen rows will be used.

When used in alternate-display mode, this is the command that gives you precise control over the size of each currently visible task
display, except for the very last. It will not affect the last window's size, as all prior task displays will have already been painted.

Note: If you wish to increase the size of the last visible task display when in alternate-display mode, simply decrease the size of the
task display(s) above it.

SORTING of task window

For compatibility, this top supports most of the former top sort keys. Since this is primarily a service to former top users, these commands
do not appear on any help screen.
command sorted-field supported
A start time (non-display) No
M %MEM Yes
N PID Yes
P %CPU Yes
T TIME+ Yes

Before using any of the following sort provisions, top suggests that you temporarily turn on column highlighting using the `x' interactive
command. That will help ensure that the actual sort environment matches your intent.

The following interactive commands will only be honored when the current sort field is visible. The sort field might not be visible because:
1) there is insufficient Screen Width
2) the `f' interactive command turned it Off

< :Move-Sort-Field-Left
Moves the sort column to the left unless the current sort field is the first field being displayed.

> :Move-Sort-Field-Right
Moves the sort column to the right unless the current sort field is the last field being displayed.

The following interactive commands will always be honored whether or not the current sort field is visible.

f | F :Fields-Management
These keys display a separate screen where you can change which field is used as the sort column, among other functions. This can be a
convenient way to simply verify the current sort field, when running top with column highlighting turned Off.

R :Reverse/Normal-Sort-Field toggle
Using this interactive command you can alternate between high-to-low and low-to-high sorts.

Note: Field sorting uses internal values, not those in column display. Thus, the TTY and WCHAN fields will violate strict ASCII collating
sequence.

4d. COLOR Mapping

       When you issue the `Z' interactive command, you will be presented with a separate screen.  That screen can be used to change the colors  in  just
       the `current' window or in all four windows before returning to the top display.

       The following interactive commands are available.
           4 upper case letters to select a target
           8 numbers to select a color
           normal toggles available
               B         :bold disable/enable
               b         :running tasks "bold"/reverse
               z         :color/mono
           other commands available
               a/w       :apply, then go to next/prior
               <Enter>   :apply and exit
               q         :abandon current changes and exit

       If  you  use  `a'  or `w' to cycle the targeted window, you will have applied the color scheme that was displayed when you left that window.  You
       can, of course, easily return to any window and reapply different colors or turn colors Off completely with the `z' toggle.

       The Color Mapping screen can also be used to change the `current' window/field group  in  either  full-screen  mode  or  alternate-display  mode.
       Whatever was targeted when `q' or <Enter> was pressed will be made current as you return to the top display.

5. ALTERNATE-DISPLAY Provisions

5a. WINDOWS Overview

       Field Groups/Windows:
          In  full-screen  mode  there  is  a single window represented by the entire screen.  That single window can still be changed to display 1 of 4
          different field groups (see the `g' interactive command, repeated below).  Each of the 4 field groups has  a  unique  separately  configurable
          summary area and its own configurable task area.

          In  alternate-display  mode, those 4 underlying field groups can now be made visible simultaneously, or can be turned Off individually at your
          command.

          The summary area will always exist, even if it's only the message line.  At any given time only one summary area can be  displayed.   However,
          depending on your commands, there could be from zero to four separate task displays currently showing on the screen.

       Current Window:
          The  `current' window is the window associated with the summary area and the window to which task related commands are always directed.  Since
          in alternate-display mode you can toggle the task display Off, some commands might be restricted for the `current' window.

          A further complication arises when you have toggled the first summary area line Off.  With the loss of the window name (the `l' toggled line),
          you'll not easily know what window is the `current' window.

5b. COMMANDS for Windows

| _ :Show/Hide-Window(s) toggles The `-‘ key turns the `current’ window’s task display On and Off. When On, that task area will show a minimum of the columns header you’ve established with the `f’ interactive command. It will also reflect any other task area options/toggles you’ve applied yielding zero or more tasks.

The `_' key does the same for all task displays. In other words, it switches between the currently visible task display(s) and any task
display(s) you had toggled Off. If all 4 task displays are currently visible, this interactive command will leave the summary area as the
only display element.

* = | + :Equalize/Reset-Window(s)
The `=' key forces the `current' window's task display to be visible. It also reverses any active `i' (idle tasks), `n' (max tasks),
`u/U' (user filter), `o/O' (other filter), `v' (hide children), `L' (locate) and `!' (combine cpus) commands. Also, if the window had
been scrolled, it will be reset with this command. See topic 5c. SCROLLING a Window for additional information regarding vertical and
horizontal scrolling.

The `+' key does the same for all windows. The four task displays will reappear, evenly balanced, while retaining any customizations
previously applied beyond those noted for the `=' command toggle.

* A :Alternate-Display-Mode toggle
This command will switch between full-screen mode and alternate-display mode.

The first time you issue this command, all four task displays will be shown. Thereafter when you switch modes, you will see only the task
display(s) you've chosen to make visible.

* a | w :Next-Window-Forward/Backward
This will change the `current' window, which in turn changes the window to which commands are directed. These keys act in a circular
fashion so you can reach any desired window using either key.

Assuming the window name is visible (you have not toggled `l' Off), whenever the `current' window name loses its emphasis/color, that's a
reminder the task display is Off and many commands will be restricted.

* g :Choose-Another-Window/Field-Group
You will be prompted to enter a number between 1 and 4 designating the field group which should be made the `current' window.

In full-screen mode, this command is necessary to alter the `current' window. In alternate-display mode, it is simply a less convenient
alternative to the `a' and `w' commands.

G :Change-Window/Field-Group-Name
You will be prompted for a new name to be applied to the `current' window. It does not require that the window name be visible (the `l'
toggle to be On).

The interactive commands shown with an asterisk (`') have use beyond alternate-display mode.
=, A, g are always available
a, w act the same with color mapping
and fields management

5c. SCROLLING a Window

Typically a task window is a partial view into a systems's total tasks/threads which shows only some of the available fields/columns. With these
scrolling keys, you can move that view vertically or horizontally to reveal any desired task or column.

Up,PgUp :Scroll-Tasks
Move the view up toward the first task row, until the first task is displayed at the top of the `current' window. The Up arrow key moves a
single line while PgUp scrolls the entire window.

Down,PgDn :Scroll-Tasks
Move the view down toward the last task row, until the last task is the only task displayed at the top of the `current' window. The Down
arrow key moves a single line while PgDn scrolls the entire window.

Left,Right :Scroll-Columns
Move the view of displayable fields horizontally one column at a time.

Note: As a reminder, some fields/columns are not fixed-width but allocated all remaining screen width when visible. When scrolling right or
left, that feature may produce some unexpected results initially.

Additionally, there are special provisions for any variable width field when positioned as the last displayed field. Once that field is
reached via the right arrow key, and is thus the only column shown, you can continue scrolling horizontally within such a field. See the `C'
interactive command below for additional information.

Home :Jump-to-Home-Position
Reposition the display to the un-scrolled coordinates.

End :Jump-to-End-Position
Reposition the display so that the rightmost column reflects the last displayable field and the bottom task row represents the last task.

Note: From this position it is still possible to scroll down and right using the arrow keys. This is true until a single column and a single
task is left as the only display element.

C :Show-scroll-coordinates toggle
Toggle an informational message which is displayed whenever the message line is not otherwise being used. That message will take one of two
forms depending on whether or not a variable width column has also been scrolled.

scroll coordinates: y = n/n (tasks), x = n/n (fields)
scroll coordinates: y = n/n (tasks), x = n/n (fields) + nn

The coordinates shown as n/n are relative to the upper left corner of the `current' window. The additional `+ nn' represents the
displacement into a variable width column when it has been scrolled horizontally. Such displacement occurs in normal 8 character tab stop
amounts via the right and left arrow keys.

y = n/n (tasks)
The first n represents the topmost visible task and is controlled by scrolling keys. The second n is updated automatically to reflect
total tasks.

x = n/n (fields)
The first n represents the leftmost displayed column and is controlled by scrolling keys. The second n is the total number of
displayable fields and is established with the `f' interactive command.

The above interactive commands are always available in full-screen mode but never available in alternate-display mode if the `current' window's
task display has been toggled Off.

Note: When any form of filtering is active, you can expect some slight aberrations when scrolling since not all tasks will be visible. This is
particularly apparent when using the Up/Down arrow keys.

5d. SEARCHING in a Window

You can use these interactive commands to locate a task row containing a particular value.

L :Locate-a-string
You will be prompted for the case-sensitive string to locate starting from the current window coordinates. There are no restrictions on
search string content.

Searches are not limited to values from a single field or column. All of the values displayed in a task row are allowed in a search string.
You may include spaces, numbers, symbols and even forest view artwork.

Keying <Enter> with no input will effectively disable the `&' key until a new search string is entered.

& :Locate-next
Assuming a search string has been established, top will attempt to locate the next occurrence.

When a match is found, the current window is repositioned vertically so the task row containing that string is first. The scroll coordinates
message can provide confirmation of such vertical repositioning (see the `C' interactive command). Horizontal scrolling, however, is never
altered via searching.

The availability of a matching string will be influenced by the following factors.

a. Which fields are displayable from the total available,
see topic 3b. MANAGING Fields.

b. Scrolling a window vertically and/or horizontally,
see topic 5c. SCROLLING a Window.

c. The state of the command/command-line toggle,
see the `c' interactive command.

d. The stability of the chosen sort column,
for example PID is good but %CPU bad.

If a search fails, restoring the `current' window home (unscrolled) position, scrolling horizontally, displaying command-lines or choosing a more
stable sort field could yet produce a successful `&' search.

The above interactive commands are always available in full-screen mode but never available in alternate-display mode if the `current' window's
task display has been toggled Off.

Note: Whenever a Search is active in a window, top will turn column highlighting Off to prevent false matches on internal non-display escape
sequences. Such highlighting will be restored when a window's search string is empty. See the `x' interactive command for additional
information on sort column highlighting.

5e. FILTERING in a Window

You can use this `Other Filter' feature to establish selection criteria which will then determine which tasks are shown in the `current' window.
Such filters can be made presistent if preserved in the rcfile via the 'W' interactive command.

Establishing a filter requires: 1) a field name; 2) an operator; and 3) a selection value, as a minimum. This is the most complex of top's user
input requirements so, when you make a mistake, command recall will be your friend. Remember the Up/Down arrow keys or their aliases when
prompted for input.

Filter Basics

1. field names are case sensitive and spelled as in the header

2. selection values need not comprise the full displayed field

3. a selection is either case insensitive or sensitive to case

4. the default is inclusion, prepending `!' denotes exclusions

5. multiple selection criteria can be applied to a task window

6. inclusion and exclusion criteria can be used simultaneously

7. the 1 equality and 2 relational filters can be freely mixed

8. separate unique filters are maintained for each task window

If a field is not turned on or is not currently in view, then your selection criteria will not affect the display. Later, should a filtered
field become visible, the selection criteria will then be applied.

Keyboard Summary

o :Other-Filter (lower case)
You will be prompted to establish a filter that ignores case when matching.

O :Other-Filter (upper case)
You will be prompted to establish a case sensitive filter.

^O :Show-Active-Filters (Ctrl key + `o')
This can serve as a reminder of which filters are active in the `current' window. A summary will be shown on the message line until you
press the <Enter> key.

= :Reset-Filtering in current window
This clears all of your selection criteria in the `current' window. It also has additional impact so please see topic 4a. GLOBAL Commands.

+ :Reset-Filtering in all windows
This clears the selection criteria in all windows, assuming you are in alternate-display mode. As with the `=' interactive command, it too
has additional consequences so you might wish to see topic 5b. COMMANDS for Windows.

Input Requirements

When prompted for selection criteria, the data you provide must take one of two forms. There are 3 required pieces of information, with a 4th
as optional. These examples use spaces for clarity but your input generally would not.
#1 #2 #3 ( required )
Field-Name ? include-if-value
! Field-Name ? exclude-if-value
#4 ( optional )

Items #1, #3 and #4 should be self-explanatory. Item #2 represents both a required delimiter and the operator which must be one of either
equality (`=') or relation (`<' or `>').

The `=' equality operator requires only a partial match and that can reduce your `if-value' input requirements. The `>' or `<' relational
operators always employ string comparisons, even with numeric fields. They are designed to work with a field's default justification and with
homogeneous data. When some field's numeric amounts have been subjected to scaling while others have not, that data is no longer homogeneous.

If you establish a relational filter and you have changed the default Numeric or Character justification, that filter is likely to fail. When
a relational filter is applied to a memory field and you have not changed the scaling, it may produce misleading results. This happens, for
example, because `100.0m' (MiB) would appear greater than `1.000g' (GiB) when compared as strings.

If your filtered results appear suspect, simply altering justification or scaling may yet achieve the desired objective. See the `j', `J' and
`e' interactive commands for additional information.

Potential Problems

These GROUP filters could produce the exact same results or the second one might not display anything at all, just a blank task window.
GROUP=root ( only the same results when )
GROUP=ROOT ( invoked via lower case `o' )

Either of these RES filters might yield inconsistent and/or misleading results, depending on the current memory scaling factor. Or both
filters could produce the exact same results.
RES>9999 ( only the same results when )
!RES<10000 ( memory scaling is at `KiB' )

This nMin filter illustrates a problem unique to scalable fields. This particular field can display a maximum of 4 digits, beyond which
values are automatically scaled to KiB or above. So while amounts greater than 9999 exist, they will appear as 2.6m, 197k, etc.
nMin>9999 ( always a blank task window )

Potential Solutions

These examples illustrate how Other Filtering can be creatively applied to achieve almost any desired result. Single quotes are sometimes
shown to delimit the spaces which are part of a filter or to represent a request for status (^O) accurately. But if you used them with if-
values in real life, no matches would be found.

Assuming field nTH is displayed, the first filter will result in only multi-threaded processes being shown. It also reminds us that a
trailing space is part of every displayed field. The second filter achieves the exact same results with less typing.
!nTH=` 1 ' ( ' for clarity only )
nTH>1 ( same with less i/p )

With Forest View mode active and the COMMAND column in view, this filter effectively collapses child processes so that just 3 levels are
shown.
!COMMAND=` `- ' ( ' for clarity only )

The final two filters appear as in response to the status request key (^O). In reality, each filter would have required separate input. The
PR example shows the two concurrent filters necessary to display tasks with priorities of 20 or more, since some might be negative. Then by
exploiting trailing spaces, the nMin series of filters could achieve the failed `9999' objective discussed above.
`PR>20' + `!PR=-' ( 2 for right result )
`!nMin=0 ' + `!nMin=1 ' + `!nMin=2 ' + `!nMin=3 ' ...

Note: Whenever Other Filtering is active in a window, top will turn column highlighting Off to prevent false matches on internal non-display
escape sequences. Such highlighting will be restored when a window is no longer subject to filtering. See the `x' interactive command for
additional information on sort column highlighting.

6. FILES

6a. PERSONAL Configuration File

This file is created or updated via the ‘W’ interactive command.

The legacy version is written as `$HOME/.your-name-4-top’ + `rc’ with a leading period.

       A  newly  created  configuration  file  is  written  as  procps/your-name-4-top'  +  `rc' without a leading period.  The procps directory will be
       subordinate to either $XDG_CONFIG_HOME when set as an absolute path or the $HOME/.config directory.

       While not intended to be edited manually, here is the general layout:
           global   # line  1: the program name/alias notation
             "      # line  2: id,altscr,irixps,delay,curwin
           per ea   # line  a: winname,fieldscur
           window   # line  b: winflags,sortindx,maxtasks,etc
             "      # line  c: summclr,msgsclr,headclr,taskclr
           global   # line 15: additional miscellaneous settings
             "      # any remaining lines are devoted to optional
             "      # active 'other filters' discussed in section 5e above
             "      # plus 'inspect' entries discussed in section 6b below

       If a valid absolute path to the rcfile cannot be established, customizations made to a running top will be impossible to preserve.

6b. ADDING INSPECT Entries

To exploit the `Y' interactive command, you must add entries at the end of the top personal configuration file. Such entries simply reflect a
file to be read or command/pipeline to be executed whose results will then be displayed in a separate scrollable, searchable window.

If you don't know the location or name of your top rcfile, use the `W' interactive command to rewrite it and note those details.

Inspect entries can be added with a redirected echo or by editing the configuration file. Redirecting an echo risks overwriting the rcfile
should it replace (>) rather than append (>>) to that file. Conversely, when using an editor care must be taken not to corrupt existing lines,
some of which will contain unprintable data or unusual characters.

Those Inspect entries beginning with a `#' character are ignored, regardless of content. Otherwise they consist of the following 3 elements,
each of which must be separated by a tab character (thus 2 `\t' total):

.type: literal `file' or `pipe'
.name: selection shown on the Inspect screen
.fmts: string representing a path or command

The two types of Inspect entries are not interchangeable. Those designated `file' will be accessed using fopen and must reference a single file
in the `.fmts' element. Entries specifying `pipe' will employ popen, their `.fmts' element could contain many pipelined commands and, none can
be interactive.

If the file or pipeline represented in your `.fmts' deals with the specific PID input or accepted when prompted, then the format string must also
contain the `%d' specifier, as these examples illustrate.

.fmts= /proc/%d/numa_maps
.fmts= lsof -P -p %d

For `pipe' type entries only, you may also wish to redirect stderr to stdout for a more comprehensive result. Thus the format string becomes:

.fmts= pmap -x %d 2>&1

Here are examples of both types of Inspect entries as they might appear in the rcfile. The first entry will be ignored due to the initial `#'
character. For clarity, the pseudo tab depictions (^I) are surrounded by an extra space but the actual tabs would not be.

# pipe ^I Sockets ^I lsof -n -P -i 2>&1
pipe ^I Open Files ^I lsof -P -p %d 2>&1
file ^I NUMA Info ^I /proc/%d/numa_maps
pipe ^I Log ^I tail -n100 /var/log/syslog | sort -Mr

Except for the commented entry above, these next examples show what could be echoed to achieve similar results, assuming the rcfile name was
`.toprc'. However, due to the embedded tab characters, each of these lines should be preceded by `/bin/echo -e', not just a simple an `echo', to
enable backslash interpretation regardless of which shell you use.

"pipe\tOpen Files\tlsof -P -p %d 2>&1" >> ~/.toprc
"file\tNUMA Info\t/proc/%d/numa_maps" >> ~/.toprc
"pipe\tLog\ttail -n200 /var/log/syslog | sort -Mr" >> ~/.toprc

If any inspect entry you create produces output with unprintable characters they will be displayed in either the ^C notation or hexadecimal <FF>
form, depending on their value. This applies to tab characters as well, which will show as `^I'. If you want a truer representation, any
embedded tabs should be expanded. The following example takes what could have been a `file' entry but employs a `pipe' instead so as to expand
the embedded tabs.

# next would have contained `\t' ...
# file ^I <your_name> ^I /proc/%d/status
# but this will eliminate embedded `\t' ...
pipe ^I <your_name> ^I cat /proc/%d/status | expand -

Note: Some programs might rely on SIGINT to end. Therefore, if a `pipe' such as the following is established, one must use Ctrl-C to terminate
it in order to review the results. This is the single occasion where a `^C' will not also terminate top.

pipe ^I Trace ^I /usr/bin/strace -p %d 2>&1

Lastly, while `pipe' type entries have been discussed in terms of pipelines and commands, there is nothing to prevent you from including shell
scripts as well. Perhaps even newly created scripts designed specifically for the `Y' interactive command.

For example, as the number of your Inspect entries grows over time, the `Options:' row will be truncated when screen width is exceeded. That
does not affect operation other than to make some selections invisible. However, if some choices are lost to truncation but you want to see more
options, there is an easy solution hinted at below.

Inspection Pause at pid ...
Use: left/right then <Enter> ...
Options: help 1 2 3 4 5 6 7 8 9 10 11 ...

The entries in the top rcfile would have a number for the `.name' element and the `help' entry would identify a shell script you've written
explaining what those numbered selections actually mean. In that way, many more choices can be made visible.

6c. SYSTEM Configuration File

       This configuration file represents defaults for users who have not saved their own configuration file.  The format mirrors exactly  the  personal
       configuration file and can also include `inspect' entries as explained above.

       Creating it is a simple process.

       1. Configure top appropriately for your installation and preserve that configuration with the `W' interactive command.

       2. Add and test any desired `inspect' entries.

       3. Copy that configuration file to the /etc/ directory as `topdefaultrc'.

6d. SYSTEM Restrictions File

The presence of this file will influence which version of the help screen is shown to an ordinary user.

       More  importantly,  it  will  limit  what  ordinary  users  are  allowed to do when top is running.  They will not be able to issue the following
       commands.
           k        Kill a task
           r        Renice a task
           d or s   Change delay/sleep interval

       This configuration file is not created by top.  Rather, it is created manually and placed it in the /etc/ directory as `toprc'.

       It should have exactly two lines, as shown in this example:
           s        # line 1: secure mode switch
           5.0      # line 2: delay interval in seconds

7. STUPID TRICKS Sampler

       Many of these tricks work best when you give top a scheduling boost.  So plan on starting him with a nice value of -10, assuming you've  got  the
       authority.

7a. Kernel Magic

For these stupid tricks, top needs full-screen mode.

â€¢ The user interface, through prompts and help, intentionally implies that the delay interval is limited to tenths of a second. However, you're
free to set any desired delay. If you want to see Linux at his scheduling best, try a delay of .09 seconds or less.

For this experiment, under x-windows open an xterm and maximize it. Then do the following:
. provide a scheduling boost and tiny delay via:
nice -n -10 top -d.09
. keep sorted column highlighting Off so as to
minimize path length
. turn On reverse row highlighting for emphasis
. try various sort columns (TIME/MEM work well),
and normal or reverse sorts to bring the most
active processes into view

What you'll see is a very busy Linux doing what he's always done for you, but there was no program available to illustrate this.

â€¢ Under an xterm using `white-on-black' colors, on top's Color Mapping screen set the task color to black and be sure that task highlighting is
set to bold, not reverse. Then set the delay interval to around .3 seconds.

After bringing the most active processes into view, what you'll see are the ghostly images of just the currently running tasks.

â€¢ Delete the existing rcfile, or create a new symlink. Start this new version then type `T' (a secret key, see topic 4c. Task Area Commands,
SORTING) followed by `W' and `q'. Finally, restart the program with -d0 (zero delay).

Your display will be refreshed at three times the rate of the former top, a 300% speed advantage. As top climbs the TIME ladder, be as
patient as you can while speculating on whether or not top will ever reach the top.

7b. Bouncing Windows

For these stupid tricks, top needs alternate-display mode.

       â€¢  With 3 or 4 task displays visible, pick any window other than the last and turn idle processes Off using the `i' command toggle.  Depending on
          where you applied `i', sometimes several task displays are bouncing and sometimes it's like an accordion, as top tries his  best  to  allocate
          space.

       â€¢  Set  each  window's summary lines differently: one with no memory (`m'); another with no states (`t'); maybe one with nothing at all, just the
          message line.  Then hold down `a' or `w' and watch a variation on bouncing windows  --  hopping windows.

       â€¢  Display all 4 windows and for each, in turn, set idle processes to Off using the `i' command toggle.  You've just entered the "extreme bounce"
          zone.

7c. The Big Bird Window

This stupid trick also requires alternate-display mode.

       â€¢  Display  all  4  windows and make sure that 1:Def is the `current' window.  Then, keep increasing window size with the `n' interactive command
          until all the other task displays are "pushed out of the nest".

          When they've all been displaced, toggle between all visible/invisible windows using the `_' command toggle.  Then ponder this:
             is top fibbing or telling honestly your imposed truth?

7d. The Ol’ Switcheroo

This stupid trick works best without alternate-display mode, since justification is active on a per window basis.

       â€¢  Start top and make COMMAND the last (rightmost) column displayed.  If necessary, use the `c' command  toggle  to  display  command  lines  and
          ensure that forest view mode is active with the `V' command toggle.

          Then  use  the up/down arrow keys to position the display so that some truncated command lines are shown (`+' in last position).  You may have
          to resize your xterm to produce truncation.

          Lastly, use the `j' command toggle to make the COMMAND column right justified.

          Now use the right arrow key to reach the COMMAND column.  Continuing with the right arrow key, watch closely the direction of travel  for  the
          command lines being shown.

             some lines travel left, while others travel right

             eventually all lines will Switcheroo, and move right

8. BUGS

9. SEE Also

free(1), ps(1), uptime(1), atop(1), slabtop(1), vmstat(8), w(1)

procps-ng September 2020 TOP(1)

Linux manpage

manpage wc

WC(1) User Commands WC(1)

NAME

wc – print newline, word, and byte counts for each file

SYNOPSIS

       wc [OPTION]... [FILE]...
       wc [OPTION]... --files0-from=F

DESCRIPTION

       Print newline, word, and byte counts for each FILE, and a total line if more than one FILE is specified.  A word is a non-zero-length sequence of
       characters delimited by white space.

       With no FILE, or when FILE is -, read standard input.

       The options below may be used to select which counts are printed, always in the following order: newline, word,  character,  byte,  maximum  line
       length.

       -c, --bytes
              print the byte counts

       -m, --chars
              print the character counts

       -l, --lines
              print the newline counts

       --files0-from=F
              read input from the files specified by NUL-terminated names in file F; If F is - then read names from standard input

       -L, --max-line-length
              print the maximum display width

       -w, --words
              print the word counts

       --help display this help and exit

       --version
              output version information and exit

AUTHOR

Written by Paul Rubin and David MacKenzie.

REPORTING BUGS

       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
       Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT

       Copyright Â© 2020 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

       Full documentation <https://www.gnu.org/software/coreutils/wc>
       or available locally via: info '(coreutils) wc invocation'

GNU coreutils 8.32                                                   September 2020                                                                WC(1)

Linux manpage

manpage wget

WGET(1) GNU Wget WGET(1)

NAME

Wget – The non-interactive network downloader.

SYNOPSIS

wget [option]… [URL]…

DESCRIPTION

       GNU Wget is a free utility for non-interactive download of files from the Web.  It supports HTTP, HTTPS, and FTP protocols, as well as retrieval
       through HTTP proxies.

       Wget is non-interactive, meaning that it can work in the background, while the user is not logged on.  This allows you to start a retrieval and
       disconnect from the system, letting Wget finish the work.  By contrast, most of the Web browsers require constant user's presence, which can be a
       great hindrance when transferring a lot of data.

       Wget can follow links in HTML, XHTML, and CSS pages, to create local versions of remote web sites, fully recreating the directory structure of
       the original site.  This is sometimes referred to as "recursive downloading."  While doing that, Wget respects the Robot Exclusion Standard
       (/robots.txt).  Wget can be instructed to convert the links in downloaded files to point at the local files, for offline viewing.

       Wget has been designed for robustness over slow or unstable network connections; if a download fails due to a network problem, it will keep
       retrying until the whole file has been retrieved.  If the server supports regetting, it will instruct the server to continue the download from
       where it left off.

OPTIONS

Option Syntax

Since Wget uses GNU getopt to process command-line arguments, every option has a long form along with the short one. Long options are more
convenient to remember, but take time to type. You may freely mix different option styles, or specify options after the command-line arguments.
Thus you may write:

wget -r --tries=10 http://fly.srk.fer.hr/ -o log

The space between the option accepting an argument and the argument may be omitted. Instead of -o log you can write -olog.

You may put several options that do not require arguments together, like:

wget -drc <URL>

This is completely equivalent to:

wget -d -r -c <URL>

Since the options can be specified after the arguments, you may terminate them with --. So the following will try to download URL -x, reporting
failure to log:

wget -o log -- -x

The options that accept comma-separated lists all respect the convention that specifying an empty list clears its value. This can be useful to
clear the .wgetrc settings. For instance, if your .wgetrc sets "exclude_directories" to /cgi-bin, the following example will first reset it, and
then set it to exclude /~nobody and /~somebody. You can also clear the lists in .wgetrc.

wget -X " -X /~nobody,/~somebody

Most options that do not accept arguments are boolean options, so named because their state can be captured with a yes-or-no ("boolean")
variable. For example, --follow-ftp tells Wget to follow FTP links from HTML files and, on the other hand, --no-glob tells it not to perform
file globbing on FTP URLs. A boolean option is either affirmative or negative (beginning with --no). All such options share several properties.

Unless stated otherwise, it is assumed that the default behavior is the opposite of what the option accomplishes. For example, the documented
existence of --follow-ftp assumes that the default is to not follow FTP links from HTML pages.

Affirmative options can be negated by prepending the --no- to the option name; negative options can be negated by omitting the --no- prefix.
This might seem superfluous---if the default for an affirmative option is to not do something, then why provide a way to explicitly turn it off?
But the startup file may in fact change the default. For instance, using "follow_ftp = on" in .wgetrc makes Wget follow FTP links by default,
and using --no-follow-ftp is the only way to restore the factory default from the command line.

Basic Startup Options

       -V
       --version
           Display the version of Wget.

       -h
       --help
           Print a help message describing all of Wget's command-line options.

       -b
       --background
           Go to background immediately after startup.  If no output file is specified via the -o, output is redirected to wget-log.

       -e command
       --execute command
           Execute command as if it were a part of .wgetrc.  A command thus invoked will be executed after the commands in .wgetrc, thus taking
           precedence over them.  If you need to specify more than one wgetrc command, use multiple instances of -e.

Logging and Input File Options

-o logfile
--output-file=logfile
Log all messages to logfile. The messages are normally reported to standard error.

-a logfile
--append-output=logfile
Append to logfile. This is the same as -o, only it appends to logfile instead of overwriting the old log file. If logfile does not exist, a
new file is created.

-d
--debug
Turn on debug output, meaning various information important to the developers of Wget if it does not work properly. Your system
administrator may have chosen to compile Wget without debug support, in which case -d will not work. Please note that compiling with debug
support is always safe---Wget compiled with the debug support will not print any debug info unless requested with -d.

-q
--quiet
Turn off Wget's output.

-v
--verbose
Turn on verbose output, with all the available data. The default output is verbose.

-nv
--no-verbose
Turn off verbose without being completely quiet (use -q for that), which means that error messages and basic information still get printed.

--report-speed=type
Output bandwidth as type. The only accepted value is bits.

-i file
--input-file=file
Read URLs from a local or external file. If - is specified as file, URLs are read from the standard input. (Use ./- to read from a file
literally named -.)

If this function is used, no URLs need be present on the command line. If there are URLs both on the command line and in an input file,
those on the command lines will be the first ones to be retrieved. If --force-html is not specified, then file should consist of a series of
URLs, one per line.

However, if you specify --force-html, the document will be regarded as html. In that case you may have problems with relative links, which
you can solve either by adding "<base href="url">" to the documents or by specifying --base=url on the command line.

If the file is an external one, the document will be automatically treated as html if the Content-Type matches text/html. Furthermore, the
file's location will be implicitly used as base href if none was specified.

--input-metalink=file
Downloads files covered in local Metalink file. Metalink version 3 and 4 are supported.

--keep-badhash
Keeps downloaded Metalink's files with a bad hash. It appends .badhash to the name of Metalink's files which have a checksum mismatch, except
without overwriting existing files.

--metalink-over-http
Issues HTTP HEAD request instead of GET and extracts Metalink metadata from response headers. Then it switches to Metalink download. If no
valid Metalink metadata is found, it falls back to ordinary HTTP download. Enables Content-Type: application/metalink4+xml files
download/processing.

--metalink-index=number
Set the Metalink application/metalink4+xml metaurl ordinal NUMBER. From 1 to the total number of "application/metalink4+xml" available.
Specify 0 or inf to choose the first good one. Metaurls, such as those from a --metalink-over-http, may have been sorted by priority key's
value; keep this in mind to choose the right NUMBER.

--preferred-location
Set preferred location for Metalink resources. This has effect if multiple resources with same priority are available.

--xattr
Enable use of file system's extended attributes to save the original URL and the Referer HTTP header value if used.

Be aware that the URL might contain private information like access tokens or credentials.

-F
--force-html
When input is read from a file, force it to be treated as an HTML file. This enables you to retrieve relative links from existing HTML files
on your local disk, by adding "<base href="url">" to HTML, or using the --base command-line option.

-B URL
--base=URL
Resolves relative links using URL as the point of reference, when reading links from an HTML file specified via the -i/--input-file option
(together with --force-html, or when the input file was fetched remotely from a server describing it as HTML). This is equivalent to the
presence of a "BASE" tag in the HTML input file, with URL as the value for the "href" attribute.

For instance, if you specify http://foo/bar/a.html for URL, and Wget reads ../baz/b.html from the input file, it would be resolved to
http://foo/baz/b.html.

--config=FILE
Specify the location of a startup file you wish to use instead of the default one(s). Use --no-config to disable reading of config files. If
both --config and --no-config are given, --no-config is ignored.

--rejected-log=logfile
Logs all URL rejections to logfile as comma separated values. The values include the reason of rejection, the URL and the parent URL it was
found in.

Download Options

--bind-address=ADDRESS
When making client TCP/IP connections, bind to ADDRESS on the local machine. ADDRESS may be specified as a hostname or IP address. This
option can be useful if your machine is bound to multiple IPs.

--bind-dns-address=ADDRESS
[libcares only] This address overrides the route for DNS requests. If you ever need to circumvent the standard settings from
/etc/resolv.conf, this option together with --dns-servers is your friend. ADDRESS must be specified either as IPv4 or IPv6 address. Wget
needs to be built with libcares for this option to be available.

--dns-servers=ADDRESSES
[libcares only] The given address(es) override the standard nameserver addresses, e.g. as configured in /etc/resolv.conf. ADDRESSES may be
specified either as IPv4 or IPv6 addresses, comma-separated. Wget needs to be built with libcares for this option to be available.

-t number
--tries=number
Set number of tries to number. Specify 0 or inf for infinite retrying. The default is to retry 20 times, with the exception of fatal errors
like "connection refused" or "not found" (404), which are not retried.

-O file
--output-document=file
The documents will not be written to the appropriate files, but all will be concatenated together and written to file. If - is used as file,
documents will be printed to standard output, disabling link conversion. (Use ./- to print to a file literally named -.)

Use of -O is not intended to mean simply "use the name file instead of the one in the URL;" rather, it is analogous to shell redirection:
wget -O file http://foo is intended to work like wget -O - http://foo > file; file will be truncated immediately, and all downloaded content
will be written there.

For this reason, -N (for timestamp-checking) is not supported in combination with -O: since file is always newly created, it will always have
a very new timestamp. A warning will be issued if this combination is used.

Similarly, using -r or -p with -O may not work as you expect: Wget won't just download the first file to file and then download the rest to
their normal names: all downloaded content will be placed in file. This was disabled in version 1.11, but has been reinstated (with a
warning) in 1.11.2, as there are some cases where this behavior can actually have some use.

A combination with -nc is only accepted if the given output file does not exist.

Note that a combination with -k is only permitted when downloading a single document, as in that case it will just convert all relative URIs
to external ones; -k makes no sense for multiple URIs when they're all being downloaded to a single file; -k can be used only when the output
is a regular file.

-nc
--no-clobber
If a file is downloaded more than once in the same directory, Wget's behavior depends on a few options, including -nc. In certain cases, the
local file will be clobbered, or overwritten, upon repeated download. In other cases it will be preserved.

When running Wget without -N, -nc, -r, or -p, downloading the same file in the same directory will result in the original copy of file being
preserved and the second copy being named file.1. If that file is downloaded yet again, the third copy will be named file.2, and so on.
(This is also the behavior with -nd, even if -r or -p are in effect.) When -nc is specified, this behavior is suppressed, and Wget will
refuse to download newer copies of file. Therefore, ""no-clobber"" is actually a misnomer in this mode---it's not clobbering that's
prevented (as the numeric suffixes were already preventing clobbering), but rather the multiple version saving that's prevented.

When running Wget with -r or -p, but without -N, -nd, or -nc, re-downloading a file will result in the new copy simply overwriting the old.
Adding -nc will prevent this behavior, instead causing the original version to be preserved and any newer copies on the server to be ignored.

When running Wget with -N, with or without -r or -p, the decision as to whether or not to download a newer copy of a file depends on the
local and remote timestamp and size of the file. -nc may not be specified at the same time as -N.

A combination with -O/--output-document is only accepted if the given output file does not exist.

Note that when -nc is specified, files with the suffixes .html or .htm will be loaded from the local disk and parsed as if they had been
retrieved from the Web.

--backups=backups
Before (over)writing a file, back up an existing file by adding a .1 suffix (_1 on VMS) to the file name. Such backup files are rotated to
.2, .3, and so on, up to backups (and lost beyond that).

--no-netrc
Do not try to obtain credentials from .netrc file. By default .netrc file is searched for credentials in case none have been passed on
command line and authentication is required.

-c
--continue
Continue getting a partially-downloaded file. This is useful when you want to finish up a download started by a previous instance of Wget,
or by another program. For instance:

wget -c ftp://sunsite.doc.ic.ac.uk/ls-lR.Z

If there is a file named ls-lR.Z in the current directory, Wget will assume that it is the first portion of the remote file, and will ask the
server to continue the retrieval from an offset equal to the length of the local file.

Note that you don't need to specify this option if you just want the current invocation of Wget to retry downloading a file should the
connection be lost midway through. This is the default behavior. -c only affects resumption of downloads started prior to this invocation
of Wget, and whose local files are still sitting around.

Without -c, the previous example would just download the remote file to ls-lR.Z.1, leaving the truncated ls-lR.Z file alone.

If you use -c on a non-empty file, and the server does not support continued downloading, Wget will restart the download from scratch and
overwrite the existing file entirely.

Beginning with Wget 1.7, if you use -c on a file which is of equal size as the one on the server, Wget will refuse to download the file and
print an explanatory message. The same happens when the file is smaller on the server than locally (presumably because it was changed on the
server since your last download attempt)---because "continuing" is not meaningful, no download occurs.

On the other side of the coin, while using -c, any file that's bigger on the server than locally will be considered an incomplete download
and only "(length(remote) - length(local))" bytes will be downloaded and tacked onto the end of the local file. This behavior can be
desirable in certain cases---for instance, you can use wget -c to download just the new portion that's been appended to a data collection or
log file.

However, if the file is bigger on the server because it's been changed, as opposed to just appended to, you'll end up with a garbled file.
Wget has no way of verifying that the local file is really a valid prefix of the remote file. You need to be especially careful of this when
using -c in conjunction with -r, since every file will be considered as an "incomplete download" candidate.

Another instance where you'll get a garbled file if you try to use -c is if you have a lame HTTP proxy that inserts a "transfer interrupted"
string into the local file. In the future a "rollback" option may be added to deal with this case.

Note that -c only works with FTP servers and with HTTP servers that support the "Range" header.

--start-pos=OFFSET
Start downloading at zero-based position OFFSET. Offset may be expressed in bytes, kilobytes with the `k' suffix, or megabytes with the `m'
suffix, etc.

--start-pos has higher precedence over --continue. When --start-pos and --continue are both specified, wget will emit a warning then proceed
as if --continue was absent.

Server support for continued download is required, otherwise --start-pos cannot help. See -c for details.

--progress=type
Select the type of the progress indicator you wish to use. Legal indicators are "dot" and "bar".

The "bar" indicator is used by default. It draws an ASCII progress bar graphics (a.k.a "thermometer" display) indicating the status of
retrieval. If the output is not a TTY, the "dot" bar will be used by default.

Use --progress=dot to switch to the "dot" display. It traces the retrieval by printing dots on the screen, each dot representing a fixed
amount of downloaded data.

The progress type can also take one or more parameters. The parameters vary based on the type selected. Parameters to type are passed by
appending them to the type sperated by a colon (:) like this: --progress=type:parameter1:parameter2.

When using the dotted retrieval, you may set the style by specifying the type as dot:style. Different styles assign different meaning to one
dot. With the "default" style each dot represents 1K, there are ten dots in a cluster and 50 dots in a line. The "binary" style has a more
"computer"-like orientation---8K dots, 16-dots clusters and 48 dots per line (which makes for 384K lines). The "mega" style is suitable for
downloading large files---each dot represents 64K retrieved, there are eight dots in a cluster, and 48 dots on each line (so each line
contains 3M). If "mega" is not enough then you can use the "giga" style---each dot represents 1M retrieved, there are eight dots in a
cluster, and 32 dots on each line (so each line contains 32M).

With --progress=bar, there are currently two possible parameters, force and noscroll.

When the output is not a TTY, the progress bar always falls back to "dot", even if --progress=bar was passed to Wget during invocation. This
behaviour can be overridden and the "bar" output forced by using the "force" parameter as --progress=bar:force.

By default, the bar style progress bar scroll the name of the file from left to right for the file being downloaded if the filename exceeds
the maximum length allotted for its display. In certain cases, such as with --progress=bar:force, one may not want the scrolling filename in
the progress bar. By passing the "noscroll" parameter, Wget can be forced to display as much of the filename as possible without scrolling
through it.

Note that you can set the default style using the "progress" command in .wgetrc. That setting may be overridden from the command line. For
example, to force the bar output without scrolling, use --progress=bar:force:noscroll.

--show-progress
Force wget to display the progress bar in any verbosity.

By default, wget only displays the progress bar in verbose mode. One may however, want wget to display the progress bar on screen in
conjunction with any other verbosity modes like --no-verbose or --quiet. This is often a desired a property when invoking wget to download
several small/large files. In such a case, wget could simply be invoked with this parameter to get a much cleaner output on the screen.

This option will also force the progress bar to be printed to stderr when used alongside the --output-file option.

-N
--timestamping
Turn on time-stamping.

--no-if-modified-since
Do not send If-Modified-Since header in -N mode. Send preliminary HEAD request instead. This has only effect in -N mode.

--no-use-server-timestamps
Don't set the local file's timestamp by the one on the server.

By default, when a file is downloaded, its timestamps are set to match those from the remote file. This allows the use of --timestamping on
subsequent invocations of wget. However, it is sometimes useful to base the local file's timestamp on when it was actually downloaded; for
that purpose, the --no-use-server-timestamps option has been provided.

-S
--server-response
Print the headers sent by HTTP servers and responses sent by FTP servers.

--spider
When invoked with this option, Wget will behave as a Web spider, which means that it will not download the pages, just check that they are
there. For example, you can use Wget to check your bookmarks:

wget --spider --force-html -i bookmarks.html

This feature needs much more work for Wget to get close to the functionality of real web spiders.

-T seconds
--timeout=seconds
Set the network timeout to seconds seconds. This is equivalent to specifying --dns-timeout, --connect-timeout, and --read-timeout, all at
the same time.

When interacting with the network, Wget can check for timeout and abort the operation if it takes too long. This prevents anomalies like
hanging reads and infinite connects. The only timeout enabled by default is a 900-second read timeout. Setting a timeout to 0 disables it
altogether. Unless you know what you are doing, it is best not to change the default timeout settings.

All timeout-related options accept decimal values, as well as subsecond values. For example, 0.1 seconds is a legal (though unwise) choice
of timeout. Subsecond timeouts are useful for checking server response times or for testing network latency.

--dns-timeout=seconds
Set the DNS lookup timeout to seconds seconds. DNS lookups that don't complete within the specified time will fail. By default, there is no
timeout on DNS lookups, other than that implemented by system libraries.

--connect-timeout=seconds
Set the connect timeout to seconds seconds. TCP connections that take longer to establish will be aborted. By default, there is no connect
timeout, other than that implemented by system libraries.

--read-timeout=seconds
Set the read (and write) timeout to seconds seconds. The "time" of this timeout refers to idle time: if, at any point in the download, no
data is received for more than the specified number of seconds, reading fails and the download is restarted. This option does not directly
affect the duration of the entire download.

Of course, the remote server may choose to terminate the connection sooner than this option requires. The default read timeout is 900
seconds.

--limit-rate=amount
Limit the download speed to amount bytes per second. Amount may be expressed in bytes, kilobytes with the k suffix, or megabytes with the m
suffix. For example, --limit-rate=20k will limit the retrieval rate to 20KB/s. This is useful when, for whatever reason, you don't want
Wget to consume the entire available bandwidth.

This option allows the use of decimal numbers, usually in conjunction with power suffixes; for example, --limit-rate=2.5k is a legal value.

Note that Wget implements the limiting by sleeping the appropriate amount of time after a network read that took less time than specified by
the rate. Eventually this strategy causes the TCP transfer to slow down to approximately the specified rate. However, it may take some time
for this balance to be achieved, so don't be surprised if limiting the rate doesn't work well with very small files.

-w seconds
--wait=seconds
Wait the specified number of seconds between the retrievals. Use of this option is recommended, as it lightens the server load by making the
requests less frequent. Instead of in seconds, the time can be specified in minutes using the "m" suffix, in hours using "h" suffix, or in
days using "d" suffix.

Specifying a large value for this option is useful if the network or the destination host is down, so that Wget can wait long enough to
reasonably expect the network error to be fixed before the retry. The waiting interval specified by this function is influenced by
"--random-wait", which see.

--waitretry=seconds
If you don't want Wget to wait between every retrieval, but only between retries of failed downloads, you can use this option. Wget will use
linear backoff, waiting 1 second after the first failure on a given file, then waiting 2 seconds after the second failure on that file, up to
the maximum number of seconds you specify.

By default, Wget will assume a value of 10 seconds.

--random-wait
Some web sites may perform log analysis to identify retrieval programs such as Wget by looking for statistically significant similarities in
the time between requests. This option causes the time between requests to vary between 0.5 and 1.5 * wait seconds, where wait was specified
using the --wait option, in order to mask Wget's presence from such analysis.

A 2001 article in a publication devoted to development on a popular consumer platform provided code to perform this analysis on the fly. Its
author suggested blocking at the class C address level to ensure automated retrieval programs were blocked despite changing DHCP-supplied
addresses.

The --random-wait option was inspired by this ill-advised recommendation to block many unrelated users from a web site due to the actions of
one.

--no-proxy
Don't use proxies, even if the appropriate *_proxy environment variable is defined.

-Q quota
--quota=quota
Specify download quota for automatic retrievals. The value can be specified in bytes (default), kilobytes (with k suffix), or megabytes
(with m suffix).

Note that quota will never affect downloading a single file. So if you specify wget -Q10k https://example.com/ls-lR.gz, all of the ls-lR.gz
will be downloaded. The same goes even when several URLs are specified on the command-line. The quota is checked only at the end of each
downloaded file, so it will never result in a partially downloaded file. Thus you may safely type wget -Q2m -i sites---download will be
aborted after the file that exhausts the quota is completely downloaded.

Setting quota to 0 or to inf unlimits the download quota.

--no-dns-cache
Turn off caching of DNS lookups. Normally, Wget remembers the IP addresses it looked up from DNS so it doesn't have to repeatedly contact
the DNS server for the same (typically small) set of hosts it retrieves from. This cache exists in memory only; a new Wget run will contact
DNS again.

However, it has been reported that in some situations it is not desirable to cache host names, even for the duration of a short-running
application like Wget. With this option Wget issues a new DNS lookup (more precisely, a new call to "gethostbyname" or "getaddrinfo") each
time it makes a new connection. Please note that this option will not affect caching that might be performed by the resolving library or by
an external caching layer, such as NSCD.

If you don't understand exactly what this option does, you probably won't need it.

--restrict-file-names=modes
Change which characters found in remote URLs must be escaped during generation of local filenames. Characters that are restricted by this
option are escaped, i.e. replaced with %HH, where HH is the hexadecimal number that corresponds to the restricted character. This option may
also be used to force all alphabetical cases to be either lower- or uppercase.

By default, Wget escapes the characters that are not valid or safe as part of file names on your operating system, as well as control
characters that are typically unprintable. This option is useful for changing these defaults, perhaps because you are downloading to a non-
native partition, or because you want to disable escaping of the control characters, or you want to further restrict characters to only those
in the ASCII range of values.

The modes are a comma-separated set of text values. The acceptable values are unix, windows, nocontrol, ascii, lowercase, and uppercase. The
values unix and windows are mutually exclusive (one will override the other), as are lowercase and uppercase. Those last are special cases,
as they do not change the set of characters that would be escaped, but rather force local file paths to be converted either to lower- or
uppercase.

When "unix" is specified, Wget escapes the character / and the control characters in the ranges 0--31 and 128--159. This is the default on
Unix-like operating systems.

When "windows" is given, Wget escapes the characters \, |, /, :, ?, ", *, <, >, and the control characters in the ranges 0--31 and 128--159.
In addition to this, Wget in Windows mode uses + instead of : to separate host and port in local file names, and uses @ instead of ? to
separate the query portion of the file name from the rest. Therefore, a URL that would be saved as www.xemacs.org:4300/search.pl?input=blah
in Unix mode would be saved as www.xemacs.org+4300/search.pl@input=blah in Windows mode. This mode is the default on Windows.

If you specify nocontrol, then the escaping of the control characters is also switched off. This option may make sense when you are
downloading URLs whose names contain UTF-8 characters, on a system which can save and display filenames in UTF-8 (some possible byte values
used in UTF-8 byte sequences fall in the range of values designated by Wget as "controls").

The ascii mode is used to specify that any bytes whose values are outside the range of ASCII characters (that is, greater than 127) shall be
escaped. This can be useful when saving filenames whose encoding does not match the one used locally.

-4
--inet4-only
-6
--inet6-only
Force connecting to IPv4 or IPv6 addresses. With --inet4-only or -4, Wget will only connect to IPv4 hosts, ignoring AAAA records in DNS, and
refusing to connect to IPv6 addresses specified in URLs. Conversely, with --inet6-only or -6, Wget will only connect to IPv6 hosts and
ignore A records and IPv4 addresses.

Neither options should be needed normally. By default, an IPv6-aware Wget will use the address family specified by the host's DNS record.
If the DNS responds with both IPv4 and IPv6 addresses, Wget will try them in sequence until it finds one it can connect to. (Also see
"--prefer-family" option described below.)

These options can be used to deliberately force the use of IPv4 or IPv6 address families on dual family systems, usually to aid debugging or
to deal with broken network configuration. Only one of --inet6-only and --inet4-only may be specified at the same time. Neither option is
available in Wget compiled without IPv6 support.

--prefer-family=none/IPv4/IPv6
When given a choice of several addresses, connect to the addresses with specified address family first. The address order returned by DNS is
used without change by default.

This avoids spurious errors and connect attempts when accessing hosts that resolve to both IPv6 and IPv4 addresses from IPv4 networks. For
example, www.kame.net resolves to 2001:200:0:8002:203:47ff:fea5:3085 and to 203.178.141.194. When the preferred family is "IPv4", the IPv4
address is used first; when the preferred family is "IPv6", the IPv6 address is used first; if the specified value is "none", the address
order returned by DNS is used without change.

Unlike -4 and -6, this option doesn't inhibit access to any address family, it only changes the order in which the addresses are accessed.
Also note that the reordering performed by this option is stable---it doesn't affect order of addresses of the same family. That is, the
relative order of all IPv4 addresses and of all IPv6 addresses remains intact in all cases.

--retry-connrefused
Consider "connection refused" a transient error and try again. Normally Wget gives up on a URL when it is unable to connect to the site
because failure to connect is taken as a sign that the server is not running at all and that retries would not help. This option is for
mirroring unreliable sites whose servers tend to disappear for short periods of time.

--user=user
--password=password
Specify the username user and password password for both FTP and HTTP file retrieval. These parameters can be overridden using the
--ftp-user and --ftp-password options for FTP connections and the --http-user and --http-password options for HTTP connections.

--ask-password
Prompt for a password for each connection established. Cannot be specified when --password is being used, because they are mutually
exclusive.

--use-askpass=command
Prompt for a user and password using the specified command. If no command is specified then the command in the environment variable
WGET_ASKPASS is used. If WGET_ASKPASS is not set then the command in the environment variable SSH_ASKPASS is used.

You can set the default command for use-askpass in the .wgetrc. That setting may be overridden from the command line.

--no-iri
Turn off internationalized URI (IRI) support. Use --iri to turn it on. IRI support is activated by default.

You can set the default state of IRI support using the "iri" command in .wgetrc. That setting may be overridden from the command line.

--local-encoding=encoding
Force Wget to use encoding as the default system encoding. That affects how Wget converts URLs specified as arguments from locale to UTF-8
for IRI support.

Wget use the function "nl_langinfo()" and then the "CHARSET" environment variable to get the locale. If it fails, ASCII is used.

You can set the default local encoding using the "local_encoding" command in .wgetrc. That setting may be overridden from the command line.

--remote-encoding=encoding
Force Wget to use encoding as the default remote server encoding. That affects how Wget converts URIs found in files from remote encoding to
UTF-8 during a recursive fetch. This options is only useful for IRI support, for the interpretation of non-ASCII characters.

For HTTP, remote encoding can be found in HTTP "Content-Type" header and in HTML "Content-Type http-equiv" meta tag.

You can set the default encoding using the "remoteencoding" command in .wgetrc. That setting may be overridden from the command line.

--unlink
Force Wget to unlink file instead of clobbering existing file. This option is useful for downloading to the directory with hardlinks.

Directory Options

-nd
--no-directories
Do not create a hierarchy of directories when retrieving recursively. With this option turned on, all files will get saved to the current
directory, without clobbering (if a name shows up more than once, the filenames will get extensions .n).

-x
--force-directories
The opposite of -nd---create a hierarchy of directories, even if one would not have been created otherwise. E.g. wget -x
http://fly.srk.fer.hr/robots.txt will save the downloaded file to fly.srk.fer.hr/robots.txt.

-nH
--no-host-directories
Disable generation of host-prefixed directories. By default, invoking Wget with -r http://fly.srk.fer.hr/ will create a structure of
directories beginning with fly.srk.fer.hr/. This option disables such behavior.

--protocol-directories
Use the protocol name as a directory component of local file names. For example, with this option, wget -r http://host will save to
http/host/... rather than just to host/....

--cut-dirs=number
Ignore number directory components. This is useful for getting a fine-grained control over the directory where recursive retrieval will be
saved.

Take, for example, the directory at ftp://ftp.xemacs.org/pub/xemacs/. If you retrieve it with -r, it will be saved locally under
ftp ftp.xemacs.org/pub/xemacs/. While the -nH option can remove the ftp ftp.xemacs.org/ part, you are still stuck with pub/xemacs. This is where
--cut-dirs comes in handy; it makes Wget not "see" number remote directory components. Here are several examples of how --cut-dirs option
works.

No options -> ftp ftp.xemacs.org/pub/xemacs/
-nH -> pub/xemacs/
-nH --cut-dirs=1 -> xemacs/
-nH --cut-dirs=2 -> .

–cut-dirs=1 -> ftp.xemacs.org/xemacs/

           If you just want to get rid of the directory structure, this option is similar to a combination of -nd and -P.  However, unlike -nd,
           --cut-dirs does not lose with subdirectories---for instance, with -nH --cut-dirs=1, a beta/ subdirectory will be placed to xemacs/beta, as
           one would expect.

       -P prefix
       --directory-prefix=prefix
           Set directory prefix to prefix.  The directory prefix is the directory where all other files and subdirectories will be saved to, i.e. the
           top of the retrieval tree.  The default is . (the current directory).

HTTP Options

--default-page=name
Use name as the default file name when it isn't known (i.e., for URLs that end in a slash), instead of index.html.

-E
--adjust-extension
If a file of type application/xhtml+xml or text/html is downloaded and the URL does not end with the regexp \.[Hh][Tt][Mm][Ll]?, this option
will cause the suffix .html to be appended to the local filename. This is useful, for instance, when you're mirroring a remote site that
uses .asp pages, but you want the mirrored pages to be viewable on your stock Apache server. Another good use for this is when you're
downloading CGI-generated materials. A URL like http://site.com/article.cgi?25 will be saved as article.cgi?25.html.

Note that filenames changed in this way will be re-downloaded every time you re-mirror a site, because Wget can't tell that the local X.html
file corresponds to remote URL X (since it doesn't yet know that the URL produces output of type text/html or application/xhtml+xml.

As of version 1.12, Wget will also ensure that any downloaded files of type text/css end in the suffix .css, and the option was renamed from
--html-extension, to better reflect its new behavior. The old option name is still acceptable, but should now be considered deprecated.

As of version 1.19.2, Wget will also ensure that any downloaded files with a "Content-Encoding" of br, compress, deflate or gzip end in the
suffix .br, .Z, .zlib and .gz respectively.

At some point in the future, this option may well be expanded to include suffixes for other types of content, including content types that
are not parsed by Wget.

--http-user=user
--http-password=password
Specify the username user and password password on an HTTP server. According to the type of the challenge, Wget will encode them using
either the "basic" (insecure), the "digest", or the Windows "NTLM" authentication scheme.

Another way to specify username and password is in the URL itself. Either method reveals your password to anyone who bothers to run "ps".
To prevent the passwords from being seen, use the --use-askpass or store them in .wgetrc or .netrc, and make sure to protect those files from
other users with "chmod". If the passwords are really important, do not leave them lying in those files either---edit the files and delete
them after Wget has started the download.

--no-http-keep-alive
Turn off the "keep-alive" feature for HTTP downloads. Normally, Wget asks the server to keep the connection open so that, when you download
more than one document from the same server, they get transferred over the same TCP connection. This saves time and at the same time reduces
the load on the server.

This option is useful when, for some reason, persistent (keep-alive) connections don't work for you, for example due to a server bug or due
to the inability of server-side scripts to cope with the connections.

--no-cache
Disable server-side cache. In this case, Wget will send the remote server appropriate directives (Cache-Control: no-cache and Pragma: no-
cache) to get the file from the remote service, rather than returning the cached version. This is especially useful for retrieving and
flushing out-of-date documents on proxy servers.

Caching is allowed by default.

--no-cookies
Disable the use of cookies. Cookies are a mechanism for maintaining server-side state. The server sends the client a cookie using the
"Set-Cookie" header, and the client responds with the same cookie upon further requests. Since cookies allow the server owners to keep track
of visitors and for sites to exchange this information, some consider them a breach of privacy. The default is to use cookies; however,
storing cookies is not on by default.

--load-cookies file
Load cookies from file before the first HTTP retrieval. file is a textual file in the format originally used by Netscape's cookies.txt file.

You will typically use this option when mirroring sites that require that you be logged in to access some or all of their content. The login
process typically works by the web server issuing an HTTP cookie upon receiving and verifying your credentials. The cookie is then resent by
the browser when accessing that part of the site, and so proves your identity.

Mirroring such a site requires Wget to send the same cookies your browser sends when communicating with the site. This is achieved by
--load-cookies---simply point Wget to the location of the cookies.txt file, and it will send the same cookies your browser would send in the
same situation. Different browsers keep textual cookie files in different locations:

"Netscape 4.x."
The cookies are in ~/.netscape/cookies.txt.

"Mozilla and Netscape 6.x."
Mozilla's cookie file is also named cookies.txt, located somewhere under ~/.mozilla, in the directory of your profile. The full path
usually ends up looking somewhat like ~/.mozilla/default/some-weird-string/cookies.txt.

"Internet Explorer."
You can produce a cookie file Wget can use by using the File menu, Import and Export, Export Cookies. This has been tested with Internet
Explorer 5; it is not guaranteed to work with earlier versions.

"Other browsers."
If you are using a different browser to create your cookies, --load-cookies will only work if you can locate or produce a cookie file in
the Netscape format that Wget expects.

If you cannot use --load-cookies, there might still be an alternative. If your browser supports a "cookie manager", you can use it to view
the cookies used when accessing the site you're mirroring. Write down the name and value of the cookie, and manually instruct Wget to send
those cookies, bypassing the "official" cookie support:

wget --no-cookies --header "Cookie: <name>=<value>"

--save-cookies file
Save cookies to file before exiting. This will not save cookies that have expired or that have no expiry time (so-called "session cookies"),
but also see --keep-session-cookies.

--keep-session-cookies
When specified, causes --save-cookies to also save session cookies. Session cookies are normally not saved because they are meant to be kept
in memory and forgotten when you exit the browser. Saving them is useful on sites that require you to log in or to visit the home page
before you can access some pages. With this option, multiple Wget runs are considered a single browser session as far as the site is
concerned.

Since the cookie file format does not normally carry session cookies, Wget marks them with an expiry timestamp of 0. Wget's --load-cookies
recognizes those as session cookies, but it might confuse other browsers. Also note that cookies so loaded will be treated as other session
cookies, which means that if you want --save-cookies to preserve them again, you must use --keep-session-cookies again.

--ignore-length
Unfortunately, some HTTP servers (CGI programs, to be more precise) send out bogus "Content-Length" headers, which makes Wget go wild, as it
thinks not all the document was retrieved. You can spot this syndrome if Wget retries getting the same document again and again, each time
claiming that the (otherwise normal) connection has closed on the very same byte.

With this option, Wget will ignore the "Content-Length" header---as if it never existed.

--header=header-line
Send header-line along with the rest of the headers in each HTTP request. The supplied header is sent as-is, which means it must contain
name and value separated by colon, and must not contain newlines.

You may define more than one additional header by specifying --header more than once.

wget --header='Accept-Charset: iso-8859-2' \
--header='Accept-Language: hr' \
http://fly.srk.fer.hr/

Specification of an empty string as the header value will clear all previous user-defined headers.

As of Wget 1.10, this option can be used to override headers otherwise generated automatically. This example instructs Wget to connect to
localhost, but to specify foo.bar in the "Host" header:

wget --header="Host: foo.bar" http://localhost/

In versions of Wget prior to 1.10 such use of --header caused sending of duplicate headers.

--compression=type
Choose the type of compression to be used. Legal values are auto, gzip and none.

If auto or gzip are specified, Wget asks the server to compress the file using the gzip compression format. If the server compresses the file
and responds with the "Content-Encoding" header field set appropriately, the file will be decompressed automatically.

If none is specified, wget will not ask the server to compress the file and will not decompress any server responses. This is the default.

Compression support is currently experimental. In case it is turned on, please report any bugs to "bug-wget@gnu.org".

--max-redirect=number
Specifies the maximum number of redirections to follow for a resource. The default is 20, which is usually far more than necessary. However,
on those occasions where you want to allow more (or fewer), this is the option to use.

--proxy-user=user
--proxy-password=password
Specify the username user and password password for authentication on a proxy server. Wget will encode them using the "basic" authentication
scheme.

Security considerations similar to those with --http-password pertain here as well.

--referer=url
Include `Referer: url' header in HTTP request. Useful for retrieving documents with server-side processing that assume they are always being
retrieved by interactive web browsers and only come out properly when Referer is set to one of the pages that point to them.

--save-headers
Save the headers sent by the HTTP server to the file, preceding the actual contents, with an empty line as the separator.

-U agent-string
--user-agent=agent-string
Identify as agent-string to the HTTP server.

The HTTP protocol allows the clients to identify themselves using a "User-Agent" header field. This enables distinguishing the WWW software,
usually for statistical purposes or for tracing of protocol violations. Wget normally identifies as Wget/version, version being the current
version number of Wget.

However, some sites have been known to impose the policy of tailoring the output according to the "User-Agent"-supplied information. While
this is not such a bad idea in theory, it has been abused by servers denying information to clients other than (historically) Netscape or,
more frequently, Microsoft Internet Explorer. This option allows you to change the "User-Agent" line issued by Wget. Use of this option is
discouraged, unless you really know what you are doing.

Specifying empty user agent with --user-agent="" instructs Wget not to send the "User-Agent" header in HTTP requests.

--post-data=string
--post-file=file
Use POST as the method for all HTTP requests and send the specified data in the request body. --post-data sends string as data, whereas
--post-file sends the contents of file. Other than that, they work in exactly the same way. In particular, they both expect content of the
form "key1=value1&key2=value2", with percent-encoding for special characters; the only difference is that one expects its content as a
command-line parameter and the other accepts its content from a file. In particular, --post-file is not for transmitting files as form
attachments: those must appear as "key=value" data (with appropriate percent-coding) just like everything else. Wget does not currently
support "multipart/form-data" for transmitting POST data; only "application/x-www-form-urlencoded". Only one of --post-data and --post-file
should be specified.

Please note that wget does not require the content to be of the form "key1=value1&key2=value2", and neither does it test for it. Wget will
simply transmit whatever data is provided to it. Most servers however expect the POST data to be in the above format when processing HTML
Forms.

When sending a POST request using the --post-file option, Wget treats the file as a binary file and will send every character in the POST
request without stripping trailing newline or formfeed characters. Any other control characters in the text will also be sent as-is in the
POST request.

Please be aware that Wget needs to know the size of the POST data in advance. Therefore the argument to "--post-file" must be a regular
file; specifying a FIFO or something like /dev/stdin won't work. It's not quite clear how to work around this limitation inherent in
HTTP/1.0. Although HTTP/1.1 introduces chunked transfer that doesn't require knowing the request length in advance, a client can't use
chunked unless it knows it's talking to an HTTP/1.1 server. And it can't know that until it receives a response, which in turn requires the
request to have been completed -- a chicken-and-egg problem.

Note: As of version 1.15 if Wget is redirected after the POST request is completed, its behaviour will depend on the response code returned
by the server. In case of a 301 Moved Permanently, 302 Moved Temporarily or 307 Temporary Redirect, Wget will, in accordance with RFC2616,
continue to send a POST request. In case a server wants the client to change the Request method upon redirection, it should send a 303 See
Other response code.

This example shows how to log in to a server using POST and then proceed to download the desired pages, presumably only accessible to
authorized users:

# Log in to the server. This can be done only once.
wget --save-cookies cookies.txt \
--post-data 'user=foo&password=bar' \
http://example.com/auth.php

# Now grab the page or pages we care about.
wget --load-cookies cookies.txt \
-p http://example.com/interesting/article.php

If the server is using session cookies to track user authentication, the above will not work because --save-cookies will not save them (and
neither will browsers) and the cookies.txt file will be empty. In that case use --keep-session-cookies along with --save-cookies to force
saving of session cookies.

--method=HTTP-Method
For the purpose of RESTful scripting, Wget allows sending of other HTTP Methods without the need to explicitly set them using
--header=Header-Line. Wget will use whatever string is passed to it after --method as the HTTP Method to the server.

--body-data=Data-String
--body-file=Data-File
Must be set when additional data needs to be sent to the server along with the Method specified using --method. --body-data sends string as
data, whereas --body-file sends the contents of file. Other than that, they work in exactly the same way.

Currently, --body-file is not for transmitting files as a whole. Wget does not currently support "multipart/form-data" for transmitting
data; only "application/x-www-form-urlencoded". In the future, this may be changed so that wget sends the --body-file as a complete file
instead of sending its contents to the server. Please be aware that Wget needs to know the contents of BODY Data in advance, and hence the
argument to --body-file should be a regular file. See --post-file for a more detailed explanation. Only one of --body-data and --body-file
should be specified.

If Wget is redirected after the request is completed, Wget will suspend the current method and send a GET request till the redirection is
completed. This is true for all redirection response codes except 307 Temporary Redirect which is used to explicitly specify that the
request method should not change. Another exception is when the method is set to "POST", in which case the redirection rules specified under
--post-data are followed.

--content-disposition
If this is set to on, experimental (not fully-functional) support for "Content-Disposition" headers is enabled. This can currently result in
extra round-trips to the server for a "HEAD" request, and is known to suffer from a few bugs, which is why it is not currently enabled by
default.

This option is useful for some file-downloading CGI programs that use "Content-Disposition" headers to describe what the name of a downloaded
file should be.

When combined with --metalink-over-http and --trust-server-names, a Content-Type: application/metalink4+xml file is named using the
"Content-Disposition" filename field, if available.

--content-on-error
If this is set to on, wget will not skip the content when the server responds with a http status code that indicates error.

--trust-server-names
If this is set, on a redirect, the local file name will be based on the redirection URL. By default the local file name is based on the
original URL. When doing recursive retrieving this can be helpful because in many web sites redirected URLs correspond to an underlying file
structure, while link URLs do not.

--auth-no-challenge
If this option is given, Wget will send Basic HTTP authentication information (plaintext username and password) for all requests, just like
Wget 1.10.2 and prior did by default.

Use of this option is not recommended, and is intended only to support some few obscure servers, which never send HTTP authentication
challenges, but accept unsolicited auth info, say, in addition to form-based authentication.

--retry-on-host-error
Consider host errors, such as "Temporary failure in name resolution", as non-fatal, transient errors.

--retry-on-http-error=code[,code,...]
Consider given HTTP response codes as non-fatal, transient errors. Supply a comma-separated list of 3-digit HTTP response codes as argument.
Useful to work around special circumstances where retries are required, but the server responds with an error code normally not retried by
Wget. Such errors might be 503 (Service Unavailable) and 429 (Too Many Requests). Retries enabled by this option are performed subject to the
normal retry timing and retry count limitations of Wget.

Using this option is intended to support special use cases only and is generally not recommended, as it can force retries even in cases where
the server is actually trying to decrease its load. Please use wisely and only if you know what you are doing.

HTTPS (SSL/TLS) Options

To support encrypted HTTP (HTTPS) downloads, Wget must be compiled with an external SSL library. The current default is GnuTLS. In addition,
Wget also supports HSTS (HTTP Strict Transport Security). If Wget is compiled without SSL support, none of these options are available.

--secure-protocol=protocol
Choose the secure protocol to be used. Legal values are auto, SSLv2, SSLv3, TLSv1, TLSv1_1, TLSv1_2, TLSv1_3 and PFS. If auto is used, the
SSL library is given the liberty of choosing the appropriate protocol automatically, which is achieved by sending a TLSv1 greeting. This is
the default.

Specifying SSLv2, SSLv3, TLSv1, TLSv1_1, TLSv1_2 or TLSv1_3 forces the use of the corresponding protocol. This is useful when talking to old
and buggy SSL server implementations that make it hard for the underlying SSL library to choose the correct protocol version. Fortunately,
such servers are quite rare.

Specifying PFS enforces the use of the so-called Perfect Forward Security cipher suites. In short, PFS adds security by creating a one-time
key for each SSL connection. It has a bit more CPU impact on client and server. We use known to be secure ciphers (e.g. no MD4) and the TLS
protocol. This mode also explicitly excludes non-PFS key exchange methods, such as RSA.

--https-only
When in recursive mode, only HTTPS links are followed.

--ciphers
Set the cipher list string. Typically this string sets the cipher suites and other SSL/TLS options that the user wish should be used, in a
set order of preference (GnuTLS calls it 'priority string'). This string will be fed verbatim to the SSL/TLS engine (OpenSSL or GnuTLS) and
hence its format and syntax is dependent on that. Wget will not process or manipulate it in any way. Refer to the OpenSSL or GnuTLS
documentation for more information.

--no-check-certificate
Don't check the server certificate against the available certificate authorities. Also don't require the URL host name to match the common
name presented by the certificate.

As of Wget 1.10, the default is to verify the server's certificate against the recognized certificate authorities, breaking the SSL handshake
and aborting the download if the verification fails. Although this provides more secure downloads, it does break interoperability with some
sites that worked with previous Wget versions, particularly those using self-signed, expired, or otherwise invalid certificates. This option
forces an "insecure" mode of operation that turns the certificate verification errors into warnings and allows you to proceed.

If you encounter "certificate verification" errors or ones saying that "common name doesn't match requested host name", you can use this
option to bypass the verification and proceed with the download. Only use this option if you are otherwise convinced of the site's
authenticity, or if you really don't care about the validity of its certificate. It is almost always a bad idea not to check the
certificates when transmitting confidential or important data. For self-signed/internal certificates, you should download the certificate
and verify against that instead of forcing this insecure mode. If you are really sure of not desiring any certificate verification, you can
specify --check-certificate=quiet to tell wget to not print any warning about invalid certificates, albeit in most cases this is the wrong
thing to do.

--certificate=file
Use the client certificate stored in file. This is needed for servers that are configured to require certificates from the clients that
connect to them. Normally a certificate is not required and this switch is optional.

--certificate-type=type
Specify the type of the client certificate. Legal values are PEM (assumed by default) and DER, also known as ASN1.

--private-key=file
Read the private key from file. This allows you to provide the private key in a file separate from the certificate.

--private-key-type=type
Specify the type of the private key. Accepted values are PEM (the default) and DER.

--ca-certificate=file
Use file as the file with the bundle of certificate authorities ("CA") to verify the peers. The certificates must be in PEM format.

Without this option Wget looks for CA certificates at the system-specified locations, chosen at OpenSSL installation time.

--ca-directory=directory
Specifies directory containing CA certificates in PEM format. Each file contains one CA certificate, and the file name is based on a hash
value derived from the certificate. This is achieved by processing a certificate directory with the "c_rehash" utility supplied with
OpenSSL. Using --ca-directory is more efficient than --ca-certificate when many certificates are installed because it allows Wget to fetch
certificates on demand.

Without this option Wget looks for CA certificates at the system-specified locations, chosen at OpenSSL installation time.

--crl-file=file
Specifies a CRL file in file. This is needed for certificates that have been revocated by the CAs.

--pinnedpubkey=file/hashes
Tells wget to use the specified public key file (or hashes) to verify the peer. This can be a path to a file which contains a single public
key in PEM or DER format, or any number of base64 encoded sha256 hashes preceded by "sha256//" and separated by ";"

When negotiating a TLS or SSL connection, the server sends a certificate indicating its identity. A public key is extracted from this
certificate and if it does not exactly match the public key(s) provided to this option, wget will abort the connection before sending or
receiving any data.

--random-file=file
[OpenSSL and LibreSSL only] Use file as the source of random data for seeding the pseudo-random number generator on systems without
/dev/urandom.

On such systems the SSL library needs an external source of randomness to initialize. Randomness may be provided by EGD (see --egd-file
below) or read from an external source specified by the user. If this option is not specified, Wget looks for random data in $RANDFILE or,
if that is unset, in $HOME/.rnd.

If you're getting the "Could not seed OpenSSL PRNG; disabling SSL." error, you should provide random data using some of the methods
described above.

--egd-file=file
[OpenSSL only] Use file as the EGD socket. EGD stands for Entropy Gathering Daemon, a user-space program that collects data from various
unpredictable system sources and makes it available to other programs that might need it. Encryption software, such as the SSL library,
needs sources of non-repeating randomness to seed the random number generator used to produce cryptographically strong keys.

OpenSSL allows the user to specify his own source of entropy using the "RAND_FILE" environment variable. If this variable is unset, or if
the specified file does not produce enough randomness, OpenSSL will read random data from EGD socket specified using this option.

If this option is not specified (and the equivalent startup command is not used), EGD is never contacted. EGD is not needed on modern Unix
systems that support /dev/urandom.

--no-hsts
Wget supports HSTS (HTTP Strict Transport Security, RFC 6797) by default. Use --no-hsts to make Wget act as a non-HSTS-compliant UA. As a
consequence, Wget would ignore all the "Strict-Transport-Security" headers, and would not enforce any existing HSTS policy.

--hsts-file=file
By default, Wget stores its HSTS database in ~/.wget-hsts. You can use --hsts-file to override this. Wget will use the supplied file as the
HSTS database. Such file must conform to the correct HSTS database format used by Wget. If Wget cannot parse the provided file, the behaviour
is unspecified.

The Wget's HSTS database is a plain text file. Each line contains an HSTS entry (ie. a site that has issued a "Strict-Transport-Security"
header and that therefore has specified a concrete HSTS policy to be applied). Lines starting with a dash ("#") are ignored by Wget. Please
note that in spite of this convenient human-readability hand-hacking the HSTS database is generally not a good idea.

An HSTS entry line consists of several fields separated by one or more whitespace:

"<hostname> SP [<port>] SP <include subdomains> SP <created> SP <max-age>"

The hostname and port fields indicate the hostname and port to which the given HSTS policy applies. The port field may be zero, and it will,
in most of the cases. That means that the port number will not be taken into account when deciding whether such HSTS policy should be applied
on a given request (only the hostname will be evaluated). When port is different to zero, both the target hostname and the port will be
evaluated and the HSTS policy will only be applied if both of them match. This feature has been included for testing/development purposes
only. The Wget testsuite (in testenv/) creates HSTS databases with explicit ports with the purpose of ensuring Wget's correct behaviour.
Applying HSTS policies to ports other than the default ones is discouraged by RFC 6797 (see Appendix B "Differences between HSTS Policy and
Same-Origin Policy"). Thus, this functionality should not be used in production environments and port will typically be zero. The last three
fields do what they are expected to. The field include_subdomains can either be 1 or 0 and it signals whether the subdomains of the target
domain should be part of the given HSTS policy as well. The created and max-age fields hold the timestamp values of when such entry was
created (first seen by Wget) and the HSTS-defined value 'max-age', which states how long should that HSTS policy remain active, measured in
seconds elapsed since the timestamp stored in created. Once that time has passed, that HSTS policy will no longer be valid and will
eventually be removed from the database.

If you supply your own HSTS database via --hsts-file, be aware that Wget may modify the provided file if any change occurs between the HSTS
policies requested by the remote servers and those in the file. When Wget exits, it effectively updates the HSTS database by rewriting the
database file with the new entries.

If the supplied file does not exist, Wget will create one. This file will contain the new HSTS entries. If no HSTS entries were generated (no
"Strict-Transport-Security" headers were sent by any of the servers) then no file will be created, not even an empty one. This behaviour
applies to the default database file (~/.wget-hsts) as well: it will not be created until some server enforces an HSTS policy.

Care is taken not to override possible changes made by other Wget processes at the same time over the HSTS database. Before dumping the
updated HSTS entries on the file, Wget will re-read it and merge the changes.

Using a custom HSTS database and/or modifying an existing one is discouraged. For more information about the potential security threats
arose from such practice, see section 14 "Security Considerations" of RFC 6797, specially section 14.9 "Creative Manipulation of HSTS Policy
Store".

--warc-file=file
Use file as the destination WARC file.

--warc-header=string
Use string into as the warcinfo record.

--warc-max-size=size
Set the maximum size of the WARC files to size.

--warc-cdx
Write CDX index files.

--warc-dedup=file
Do not store records listed in this CDX file.

--no-warc-compression
Do not compress WARC files with GZIP.

--no-warc-digests
Do not calculate SHA1 digests.

--no-warc-keep-log
Do not store the log file in a WARC record.

--warc-tempdir=dir
Specify the location for temporary files created by the WARC writer.

FTP Options

--ftp-user=user
--ftp-password=password
Specify the username user and password password on an FTP server. Without this, or the corresponding startup option, the password defaults
to -wget@, normally used for anonymous FTP.

Another way to specify username and password is in the URL itself. Either method reveals your password to anyone who bothers to run "ps".
To prevent the passwords from being seen, store them in .wgetrc or .netrc, and make sure to protect those files from other users with
"chmod". If the passwords are really important, do not leave them lying in those files either---edit the files and delete them after Wget
has started the download.

--no-remove-listing
Don't remove the temporary .listing files generated by FTP retrievals. Normally, these files contain the raw directory listings received
from FTP servers. Not removing them can be useful for debugging purposes, or when you want to be able to easily check on the contents of
remote server directories (e.g. to verify that a mirror you're running is complete).

Note that even though Wget writes to a known filename for this file, this is not a security hole in the scenario of a user making .listing a
symbolic link to /etc/passwd or something and asking "root" to run Wget in his or her directory. Depending on the options used, either Wget
will refuse to write to .listing, making the globbing/recursion/time-stamping operation fail, or the symbolic link will be deleted and
replaced with the actual .listing file, or the listing will be written to a .listing.number file.

Even though this situation isn't a problem, though, "root" should never run Wget in a non-trusted user's directory. A user could do
something as simple as linking index.html to /etc/passwd and asking "root" to run Wget with -N or -r so the file will be overwritten.

--no-glob
Turn off FTP globbing. Globbing refers to the use of shell-like special characters (wildcards), like *, ?, [ and ] to retrieve more than one
file from the same directory at once, like:

wget ftp://gnjilux.srk.fer.hr/*.msg

By default, globbing will be turned on if the URL contains a globbing character. This option may be used to turn globbing on or off
permanently.

You may have to quote the URL to protect it from being expanded by your shell. Globbing makes Wget look for a directory listing, which is
system-specific. This is why it currently works only with Unix FTP servers (and the ones emulating Unix "ls" output).

--no-passive-ftp
Disable the use of the passive FTP transfer mode. Passive FTP mandates that the client connect to the server to establish the data
connection rather than the other way around.

If the machine is connected to the Internet directly, both passive and active FTP should work equally well. Behind most firewall and NAT
configurations passive FTP has a better chance of working. However, in some rare firewall configurations, active FTP actually works when
passive FTP doesn't. If you suspect this to be the case, use this option, or set "passive_ftp=off" in your init file.

--preserve-permissions
Preserve remote file permissions instead of permissions set by umask.

--retr-symlinks
By default, when retrieving FTP directories recursively and a symbolic link is encountered, the symbolic link is traversed and the pointed-to
files are retrieved. Currently, Wget does not traverse symbolic links to directories to download them recursively, though this feature may
be added in the future.

When --retr-symlinks=no is specified, the linked-to file is not downloaded. Instead, a matching symbolic link is created on the local
filesystem. The pointed-to file will not be retrieved unless this recursive retrieval would have encountered it separately and downloaded it
anyway. This option poses a security risk where a malicious FTP Server may cause Wget to write to files outside of the intended directories
through a specially crafted .LISTING file.

Note that when retrieving a file (not a directory) because it was specified on the command-line, rather than because it was recursed to, this
option has no effect. Symbolic links are always traversed in this case.

FTPS Options

--ftps-implicit
This option tells Wget to use FTPS implicitly. Implicit FTPS consists of initializing SSL/TLS from the very beginning of the control
connection. This option does not send an "AUTH TLS" command: it assumes the server speaks FTPS and directly starts an SSL/TLS connection. If
the attempt is successful, the session continues just like regular FTPS ("PBSZ" and "PROT" are sent, etc.). Implicit FTPS is no longer a
requirement for FTPS implementations, and thus many servers may not support it. If --ftps-implicit is passed and no explicit port number
specified, the default port for implicit FTPS, 990, will be used, instead of the default port for the "normal" (explicit) FTPS which is the
same as that of FTP, 21.

--no-ftps-resume-ssl
Do not resume the SSL/TLS session in the data channel. When starting a data connection, Wget tries to resume the SSL/TLS session previously
started in the control connection. SSL/TLS session resumption avoids performing an entirely new handshake by reusing the SSL/TLS parameters
of a previous session. Typically, the FTPS servers want it that way, so Wget does this by default. Under rare circumstances however, one
might want to start an entirely new SSL/TLS session in every data connection. This is what --no-ftps-resume-ssl is for.

--ftps-clear-data-connection
All the data connections will be in plain text. Only the control connection will be under SSL/TLS. Wget will send a "PROT C" command to
achieve this, which must be approved by the server.

--ftps-fallback-to-ftp
Fall back to FTP if FTPS is not supported by the target server. For security reasons, this option is not asserted by default. The default
behaviour is to exit with an error. If a server does not successfully reply to the initial "AUTH TLS" command, or in the case of implicit
FTPS, if the initial SSL/TLS connection attempt is rejected, it is considered that such server does not support FTPS.

Recursive Retrieval Options

-r
--recursive
Turn on recursive retrieving. The default maximum depth is 5.

-l depth
--level=depth
Set the maximum number of subdirectories that Wget will recurse into to depth. In order to prevent one from accidentally downloading very
large websites when using recursion this is limited to a depth of 5 by default, i.e., it will traverse at most 5 directories deep starting
from the provided URL. Set -l 0 or -l inf for infinite recursion depth.

wget -r -l 0 http://<site>/1.html

Ideally, one would expect this to download just 1.html. but unfortunately this is not the case, because -l 0 is equivalent to -l inf---that
is, infinite recursion. To download a single HTML page (or a handful of them), specify them all on the command line and leave away -r and
-l. To download the essential items to view a single HTML page, see page requisites.

--delete-after
This option tells Wget to delete every single file it downloads, after having done so. It is useful for pre-fetching popular pages through a
proxy, e.g.:

wget -r -nd --delete-after http://whatever.com/~popular/page/

The -r option is to retrieve recursively, and -nd to not create directories.

Note that --delete-after deletes files on the local machine. It does not issue the DELE command to remote FTP sites, for instance. Also
note that when --delete-after is specified, --convert-links is ignored, so .orig files are simply not created in the first place.

-k
--convert-links
After the download is complete, convert the links in the document to make them suitable for local viewing. This affects not only the visible
hyperlinks, but any part of the document that links to external content, such as embedded images, links to style sheets, hyperlinks to non-
HTML content, etc.

Each link will be changed in one of the two ways:

â€¢ The links to files that have been downloaded by Wget will be changed to refer to the file they point to as a relative link.

Example: if the downloaded file /foo/doc.html links to /bar/img.gif, also downloaded, then the link in doc.html will be modified to point
to ../bar/img.gif. This kind of transformation works reliably for arbitrary combinations of directories.

â€¢ The links to files that have not been downloaded by Wget will be changed to include host name and absolute path of the location they
point to.

Example: if the downloaded file /foo/doc.html links to /bar/img.gif (or to ../bar/img.gif), then the link in doc.html will be modified to
point to http://hostname/bar/img.gif.

Because of this, local browsing works reliably: if a linked file was downloaded, the link will refer to its local name; if it was not
downloaded, the link will refer to its full Internet address rather than presenting a broken link. The fact that the former links are
converted to relative links ensures that you can move the downloaded hierarchy to another directory.

Note that only at the end of the download can Wget know which links have been downloaded. Because of that, the work done by -k will be
performed at the end of all the downloads.

--convert-file-only
This option converts only the filename part of the URLs, leaving the rest of the URLs untouched. This filename part is sometimes referred to
as the "basename", although we avoid that term here in order not to cause confusion.

It works particularly well in conjunction with --adjust-extension, although this coupling is not enforced. It proves useful to populate
Internet caches with files downloaded from different hosts.

Example: if some link points to //foo.com/bar.cgi?xyz with --adjust-extension asserted and its local destination is intended to be
./foo.com/bar.cgi?xyz.css, then the link would be converted to //foo.com/bar.cgi?xyz.css. Note that only the filename part has been modified.
The rest of the URL has been left untouched, including the net path ("//") which would otherwise be processed by Wget and converted to the
effective scheme (ie. "http://").

-K
--backup-converted
When converting a file, back up the original version with a .orig suffix. Affects the behavior of -N.

-m
--mirror
Turn on options suitable for mirroring. This option turns on recursion and time-stamping, sets infinite recursion depth and keeps FTP
directory listings. It is currently equivalent to -r -N -l inf --no-remove-listing.

-p
--page-requisites
This option causes Wget to download all the files that are necessary to properly display a given HTML page. This includes such things as
inlined images, sounds, and referenced stylesheets.

Ordinarily, when downloading a single HTML page, any requisite documents that may be needed to display it properly are not downloaded. Using
-r together with -l can help, but since Wget does not ordinarily distinguish between external and inlined documents, one is generally left
with "leaf documents" that are missing their requisites.

For instance, say document 1.html contains an "<IMG>" tag referencing 1.gif and an "<A>" tag pointing to external document 2.html. Say that
2.html is similar but that its image is 2.gif and it links to 3.html. Say this continues up to some arbitrarily high number.

If one executes the command:

wget -r -l 2 http://<site>/1.html

then 1.html, 1.gif, 2.html, 2.gif, and 3.html will be downloaded. As you can see, 3.html is without its requisite 3.gif because Wget is
simply counting the number of hops (up to 2) away from 1.html in order to determine where to stop the recursion. However, with this command:

wget -r -l 2 -p http://<site>/1.html

all the above files and 3.html's requisite 3.gif will be downloaded. Similarly,

wget -r -l 1 -p http://<site>/1.html

will cause 1.html, 1.gif, 2.html, and 2.gif to be downloaded. One might think that:

wget -r -l 0 -p http://<site>/1.html

would download just 1.html and 1.gif, but unfortunately this is not the case, because -l 0 is equivalent to -l inf---that is, infinite
recursion. To download a single HTML page (or a handful of them, all specified on the command-line or in a -i URL input file) and its (or
their) requisites, simply leave off -r and -l:

wget -p http://<site>/1.html

Note that Wget will behave as if -r had been specified, but only that single page and its requisites will be downloaded. Links from that
page to external documents will not be followed. Actually, to download a single page and all its requisites (even if they exist on separate
websites), and make sure the lot displays properly locally, this author likes to use a few options in addition to -p:

wget -E -H -k -K -p http://<site>/<document>;

To finish off this topic, it's worth knowing that Wget's idea of an external document link is any URL specified in an "<A>" tag, an "<AREA>"
tag, or a "<LINK>" tag other than "<LINK REL="stylesheet">".

--strict-comments
Turn on strict parsing of HTML comments. The default is to terminate comments at the first occurrence of -->.

According to specifications, HTML comments are expressed as SGML declarations. Declaration is special markup that begins with <! and ends
with >, such as <!DOCTYPE ...>, that may contain comments between a pair of -- delimiters. HTML comments are "empty declarations", SGML
declarations without any non-comment text. Therefore,  is a valid comment, and so is , but  is not.

On the other hand, most HTML writers don't perceive comments as anything other than text delimited with , which is not quite the
same. For example, something like  works as a valid comment as long as the number of dashes is a multiple of four (!). If
not, the comment technically lasts until the next --, which may be at the other end of the document. Because of this, many popular browsers
completely ignore the specification and implement what users have come to expect: comments delimited with .

Until version 1.9, Wget interpreted comments strictly, which resulted in missing links in many web pages that displayed fine in browsers, but
had the misfortune of containing non-compliant comments. Beginning with version 1.9, Wget has joined the ranks of clients that implements
"naive" comments, terminating each comment at the first occurrence of -->.

If, for whatever reason, you want strict comment parsing, use this option to turn it on.

Recursive Accept/Reject Options

-A acclist --accept acclist
-R rejlist --reject rejlist
Specify comma-separated lists of file name suffixes or patterns to accept or reject. Note that if any of the wildcard characters, , ?, [ or
], appear in an element of acclist or rejlist, it will be treated as a pattern, rather than a suffix. In this case, you have to enclose the
pattern into quotes to prevent your shell from expanding it, like in -A ".mp3" or -A '*.mp3'.

--accept-regex urlregex
--reject-regex urlregex
Specify a regular expression to accept or reject the complete URL.

--regex-type regextype
Specify the regular expression type. Possible types are posix or pcre. Note that to be able to use pcre type, wget has to be compiled with
libpcre support.

-D domain-list
--domains=domain-list
Set domains to be followed. domain-list is a comma-separated list of domains. Note that it does not turn on -H.

--exclude-domains domain-list
Specify the domains that are not to be followed.

--follow-ftp
Follow FTP links from HTML documents. Without this option, Wget will ignore all the FTP links.

--follow-tags=list
Wget has an internal table of HTML tag / attribute pairs that it considers when looking for linked documents during a recursive retrieval.
If a user wants only a subset of those tags to be considered, however, he or she should be specify such tags in a comma-separated list with
this option.

--ignore-tags=list
This is the opposite of the --follow-tags option. To skip certain HTML tags when recursively looking for documents to download, specify them
in a comma-separated list.

In the past, this option was the best bet for downloading a single page and its requisites, using a command-line like:

wget --ignore-tags=a,area -H -k -K -r http://<site>/<document>;

However, the author of this option came across a page with tags like "<LINK REL="home" HREF="/">" and came to the realization that specifying
tags to ignore was not enough. One can't just tell Wget to ignore "<LINK>", because then stylesheets will not be downloaded. Now the best
bet for downloading a single page and its requisites is the dedicated --page-requisites option.

--ignore-case
Ignore case when matching files and directories. This influences the behavior of -R, -A, -I, and -X options, as well as globbing implemented
when downloading from FTP sites. For example, with this option, -A "*.txt" will match file1.txt, but also file2.TXT, file3.TxT, and so on.
The quotes in the example are to prevent the shell from expanding the pattern.

-H
--span-hosts
Enable spanning across hosts when doing recursive retrieving.

-L
--relative
Follow relative links only. Useful for retrieving a specific home page without any distractions, not even those from the same hosts.

-I list
--include-directories=list
Specify a comma-separated list of directories you wish to follow when downloading. Elements of list may contain wildcards.

-X list
--exclude-directories=list
Specify a comma-separated list of directories you wish to exclude from download. Elements of list may contain wildcards.

-np
--no-parent
Do not ever ascend to the parent directory when retrieving recursively. This is a useful option, since it guarantees that only the files
below a certain hierarchy will be downloaded.

ENVIRONMENT

       Wget supports proxies for both HTTP and FTP retrievals.  The standard way to specify proxy location, which Wget recognizes, is using the
       following environment variables:

       http_proxy
       https_proxy
           If set, the http_proxy and https_proxy variables should contain the URLs of the proxies for HTTP and HTTPS connections respectively.

       ftp_proxy
           This variable should contain the URL of the proxy for FTP connections.  It is quite common that http_proxy and ftp_proxy are set to the same
           URL.

       no_proxy
           This variable should contain a comma-separated list of domain extensions proxy should not be used for.  For instance, if the value of
           no_proxy is .mit.edu, proxy will not be used to retrieve documents from MIT.

EXIT STATUS

Wget may return one of several error codes if it encounters problems.

0 No problems occurred.

1 Generic error code.

2 Parse error—for instance, when parsing command-line options, the .wgetrc or .netrc…

3 File I/O error.

4 Network failure.

5 SSL verification failure.

6 Username/password authentication failure.

7 Protocol errors.

8 Server issued an error response.

       With the exceptions of 0 and 1, the lower-numbered exit codes take precedence over higher-numbered ones, when multiple types of errors are
       encountered.

       In versions of Wget prior to 1.12, Wget's exit status tended to be unhelpful and inconsistent. Recursive downloads would virtually always return
       0 (success), regardless of any issues encountered, and non-recursive fetches only returned the status corresponding to the most recently-
       attempted download.

FILES

       /etc/wgetrc
           Default location of the global startup file.

       .wgetrc
           User startup file.

BUGS

You are welcome to submit bug reports via the GNU Wget bug tracker (see <https://savannah.gnu.org/bugs/?func=additem&group=wget>) or to our
mailing list <bug-wget@gnu.org>.

Visit <https://lists.gnu.org/mailman/listinfo/bug-wget> to get more info (how to subscribe, list archives, ...).

Before actually submitting a bug report, please try to follow a few simple guidelines.

1. Please try to ascertain that the behavior you see really is a bug. If Wget crashes, it's a bug. If Wget does not behave as documented, it's
a bug. If things work strange, but you are not sure about the way they are supposed to work, it might well be a bug, but you might want to
double-check the documentation and the mailing lists.

2. Try to repeat the bug in as simple circumstances as possible. E.g. if Wget crashes while downloading wget -rl0 -kKE -t5 --no-proxy
http://example.com -o /tmp/log, you should try to see if the crash is repeatable, and if will occur with a simpler set of options. You might
even try to start the download at the page where the crash occurred to see if that page somehow triggered the crash.

Also, while I will probably be interested to know the contents of your .wgetrc file, just dumping it into the debug message is probably a bad
idea. Instead, you should first try to see if the bug repeats with .wgetrc moved out of the way. Only if it turns out that .wgetrc settings
affect the bug, mail me the relevant parts of the file.

3. Please start Wget with -d option and send us the resulting output (or relevant parts thereof). If Wget was compiled without debug support,
recompile it---it is much easier to trace bugs with debug support on.

Note: please make sure to remove any potentially sensitive information from the debug log before sending it to the bug address. The "-d"
won't go out of its way to collect sensitive information, but the log will contain a fairly complete transcript of Wget's communication with
the server, which may include passwords and pieces of downloaded data. Since the bug address is publicly archived, you may assume that all
bug reports are visible to the public.

4. If Wget has crashed, try to run it in a debugger, e.g. "gdb `which wget` core" and type "where" to get the backtrace. This may not work if
the system administrator has disabled core files, but it is safe to try.

SEE ALSO

       This is not the complete manual for GNU Wget.  For more complete information, including more detailed explanations of some of the options, and a
       number of commands available for use with .wgetrc files and the -e option, see the GNU Info entry for wget.

       Also see wget2(1), the updated version of GNU Wget with even better support for recursive downloading and modern protocols like HTTP/2.

AUTHOR

       Originally written by Hrvoje NikÅ¡iÄ‡ <hniksic@xemacs.org>.  Currently maintained by Darshit Shah <darnir@gnu.org> and Tim RÃ¼hsen
       <tim.ruehsen@gmx.de>.

COPYRIGHT

       Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any
       later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts.  A
       copy of the license is included in the section entitled "GNU Free Documentation License".

GNU Wget 1.21                                                          2021-11-23                                                                WGET(1)

Linux manpage

manpage tail

TAIL(1) User Commands TAIL(1)

NAME

tail – output the last part of files

SYNOPSIS

tail [OPTION]… [FILE]…

DESCRIPTION

Print the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name.

With no FILE, or when FILE is -, read standard input.

Mandatory arguments to long options are mandatory for short options too.

       -c, --bytes=[+]NUM
              output the last NUM bytes; or use -c +NUM to output starting with byte NUM of each file

       -f, --follow[={name|descriptor}]
              output appended data as the file grows;

              an absent option argument means 'descriptor'

       -F     same as --follow=name --retry

       -n, --lines=[+]NUM
              output the last NUM lines, instead of the last 10; or use -n +NUM to output starting with line NUM

       --max-unchanged-stats=N
              with --follow=name, reopen a FILE which has not

              changed  size after N (default 5) iterations to see if it has been unlinked or renamed (this is the usual case of rotated log files); with
              inotify, this option is rarely useful

       --pid=PID
              with -f, terminate after process ID, PID dies

       -q, --quiet, --silent
              never output headers giving file names

       --retry
              keep trying to open a file if it is inaccessible

       -s, --sleep-interval=N
              with -f, sleep for approximately N seconds (default 1.0) between iterations; with inotify and --pid=P, check process P at least once every
              N seconds

       -v, --verbose
              always output headers giving file names

       -z, --zero-terminated
              line delimiter is NUL, not newline

       --help display this help and exit

       --version
              output version information and exit

       NUM  may have a multiplier suffix: b 512, kB 1000, K 1024, MB 10001000, M 10241024, GB 100010001000, G 102410241024, and so on for T, P, E,
       Z, Y.  Binary prefixes can be used, too: KiB=K, MiB=M, and so on.

       With --follow (-f), tail defaults to following the file descriptor, which means that even if a tail'ed file is renamed,  tail  will  continue  to
       track  its end.  This default behavior is not desirable when you really want to track the actual name of the file, not the file descriptor (e.g.,
       log rotation).  Use --follow=name in that case.  That causes tail to track the named file in a way that accommodates renaming, removal  and  creâАР
       ation.

AUTHOR

Written by Paul Rubin, David MacKenzie, Ian Lance Taylor, and Jim Meyering.

REPORTING BUGS

       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
       Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT

       Copyright Â© 2020 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

head(1)

       Full documentation <https://www.gnu.org/software/coreutils/tail>
       or available locally via: info '(coreutils) tail invocation'

GNU coreutils 8.32                                                   September 2020                                                              TAIL(1)