The curl command is a versatile tool in the Linux command-line interface, used for transferring data to or from a server. It supports a multitude of protocols, including HTTP, HTTPS, FTP, and more. In this blog post, we’ll delve into the curl command, providing a comprehensive understanding with practical examples.
Understanding the ‘curl’ Command
The curl command is primarily used to download or upload data. The basic syntax of the curl command is as follows:
curl [options] [URL...]
Downloading Data with ‘curl’
To download data from a URL, you simply provide the URL as an argument:
curl https://example.com
This command will send a GET request to https://example.com and print the response to the standard output.
If you want to save the response to a file, you can use the -o (output) option followed by the filename:
curl -o example.html https://example.com
This command will save the response to example.html.
Sending POST Requests with ‘curl’
The curl command can also send POST requests. To do this, you can use the -d (data) option followed by the data you want to send:
curl -d "param1=value1¶m2=value2" https://example.com
This command will send a POST request to https://example.com with the data param1=value1¶m2=value2.
Sending Headers with ‘curl’
To send headers with your request, you can use the -H (header) option:
curl -H "Content-Type: application/json" -d '{"param1":"value1","param2":"value2"}' https://example.com
This command will send a POST request to https://example.com with a JSON payload and the Content-Type: application/json header.
Conclusion
The curl command is a powerful tool for data transfer in Linux. Whether you’re downloading a webpage, sending a POST request, or setting headers, curl provides a flexible way to interact with servers directly from the command line. With the examples provided in this guide, you’re well on your way to mastering the curl command.