curl command in linux - Scaler Topics

Overview

In this article, we will discuss the curl command in Linux. The curl command is a powerful tool used for transferring data from or to a server. It supports various protocols, including HTTP, FTP, SMTP, and more. It is a command-line tool that can be used to perform different types of operations on URLs.

Linux curl Command Syntax

The syntax for the curl command is as follows:

curl Command Options:

-X, --request: Specifies the HTTP request method.
-H, --header: Allows to pass additional headers.
-d, --data: Sends HTTP POST data.
-o, --output: Writes output to a file.
-O, --remote-name: Writes output to a file with the same name as the remote file.
-I, --head: Shows headers only.
-L, --location: Follows redirects.
-u, --user: Specifies the user name and password for authentication.
-k, --insecure: Allows connections to SSL sites without certificates.
-s, --silent: Silent mode.

Example Usages

Downloading a file using curl::
Explanation: This command downloads a file from the specified URL and saves it in the current directory with the same name as the remote file.
Sending POST data using curl::
Explanation: This command sends a POST request to the specified URL with the given data.
Displaying only the response headers using curl::
Explanation: This command displays only the response headers of the specified URL.
Following redirects using curl::
Explanation: This command follows any redirects that occur while accessing the specified URL.

Tips

You can use the -o option to write the output to a specific file instead of stdout.
You can use the -u option to specify a user name and password for server authentication.

Advanced Use Cases of curl Command in Linux

Uploading a file using curl::
Explanation: This command uploads a file to the specified URL using HTTP POST method.
Using a proxy server with curl::
Explanation: This command accesses the specified URL using the specified proxy server and port.
Displaying SSL certificate information using curl::
Explanation: This command displays SSL certificate information while accessing the specified URL.

Conclusion

The curl command is a powerful tool for transferring data to and from a server.
It supports various protocols including HTTP, FTP, SMTP, and more.
The curl command has many options for customizing requests and responses.
It is a command-line tool that is available on most Linux distributions.
Curl can be used for downloading files, sending POST data, displaying headers, following redirects, and more.