curl for HTTP requests in Linux CLI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is curl used for in the command line?

curl is a tool to send and receive data from URLs using various protocols like HTTP. It helps you talk to websites or APIs from the terminal.

beginner

How do you make a simple GET request to https://example.com using curl?

Use the command: curl https://example.com. This fetches the webpage content and shows it in the terminal.

intermediate

What option do you use with curl to send data with a POST request?

Use -d or --data followed by the data string. For example: curl -d "name=John" https://example.com sends a POST request with data.

beginner

How can you save the output of a curl request to a file?

Use the -o option followed by the filename. Example: curl https://example.com -o page.html saves the content to page.html.

intermediate

What does the -I option do in curl?

The -I option fetches only the HTTP headers from the server, not the full content. Useful to check status or server info.

Which curl command fetches only HTTP headers from a URL?

A curl -X POST https://example.com

B curl -d https://example.com

C curl -I https://example.com

D curl -o https://example.com

The -I option tells curl to fetch only headers.

How do you send form data "name=Anna" with a POST request using curl?

A curl -d "name=Anna" https://example.com

B curl -X GET https://example.com

C curl -I https://example.com

D curl -o data.txt https://example.com

-d sends data with POST by default.

What does curl https://example.com -o file.html do?

A Deletes <code>file.html</code>

B Sends a POST request

C Fetches only headers

D Saves the webpage content to <code>file.html</code>

-o saves output to a file.

Which protocol is NOT supported by curl?

A HTTP

B SSH

C SMTP

D FTP

curl supports HTTP, FTP, SMTP but not SSH.

What is the default HTTP method used by curl if none is specified?

A GET

B POST

C PUT

D DELETE

curl uses GET by default.

Explain how to use curl to send a POST request with data and save the response to a file.

Think about how to send data and where to put the response.

Describe how to check only the HTTP headers of a website using curl and why this might be useful.

Headers tell you about the server response without the full page.