How to install Curl?
On Linux, enter the following command to install Curl:
Then check Curl by executing the following command:
To use Curl on Windows, download the installer from the Curl official website and unpack the curl.zip archive to the desired local folder on your computer. Add the Curl folder (usually C:\Curl\bin) to your Windows PATH environment variable to invoke the Curl command from anywhere else. Enter curl --version on the command line to make sure you can use Curl on Windows.
Curl comes with macOS already. You can update Curl to the latest version by installing macOS Homebrew Software Package Manager. After installing Homebrew, open a Terminal and type:
How to use the Curl command-line tool?
Below is a list of the 12 best Curl commands that you will use the most during your work.
1. Get resource content by URL
If no parameters are specified, Curl sends an HTTP GET request to the server and outputs the resource's content (for example, the HTML code of a page) to standard output (usually a terminal window).
2. Save URL content to a file
The Curl -o command-line option tells Curl to save the contents of the URL in the current working directory with the specified file name. The resource is downloaded with the HTTP GET request method.
3. Download multiple files at once
The list of URLs is passed to Curl with one of the -o or -O command-line options. As we saw in example #2, for the command line parameter -o, you can pass the file name under which the resource will be saved, and the -O command line parameter tells Curl to save the downloaded resource with the original file name.
5. Check Page HTTP headers
The -I parameter tells Curl to send an HTTP HEAD request to the server instead of a GET. The HEAD request is similar to a GET, except that the server only returns HTTP headers. This is useful if you only want to check the URL headers and not load the page content (to save Internet traffic).
6. Force Curl to use HTTP/2 protocol
The --http2 option forces Curl to use the HTTP/2 protocol instead of HTTP/1.1. Combined with the -I command line parameter, we can use this Curl command to check if a website supports HTTP/2.
7. Do Follow Redirects
By default, Curl does not follow redirects (HTTP status codes 301 and 302). The -L option tells Curl to do HTTP redirects.
8. Use proxy server
If you are behind a proxy server, the -x command-line option will allow you to send requests through the proxy server. The -U command-line option passes the proxy username and password to the proxy.
9. Provide additional HTTP headers with request
The -H command-line option allows additional HTTP headers to be passed to the server. You can provide as many HTTP headers as you want using the -H option multiple times.
10. Send data to the server
The -d command line parameter tells Curl to send the supplied data to the server using the HTTP POST request method. The -d option is usually followed by the -H parameter to indicate the data type.
11. Change the User-Agent string
The --user-agent command-line option allows you to pass any string to be used instead of the standard Curl User-Agent string. This can be useful if the server only expects requests from certain browsers.
12. Send Cookies to Website
The -b command line parameter allows you to send cookies back to the website. You can use the -b switch with the file's name that contains the cookies or pass the cookies in the string.