What Is the curl Command in Linux?¶

Introduction¶

The curl command transfers data to or from URLs and APIs. It is useful for beginners, Linux administrators, DevOps engineers, and RHCSA students because it solves practical terminal tasks.

What the Command Does¶

Use curl to work with the specific Linux object it manages. Before changing anything, identify the target and run a read-only check when possible.

Basic Syntax¶

curl OPTIONS URL

The syntax includes the command, any options, and the target object.

Common Options¶

• -I: fetch response headers only.
• -L: follow redirects.
• -H: send an HTTP header.

Practical Examples¶

curl https://example.com
curl -I https://example.com
curl -o index.html https://example.com
curl -H "Accept: application/json" https://api.example.com/status

Verification command:

curl --version

Example output:

HTTP/2 200
content-type: text/html; charset=UTF-8

When to Use This Command¶

Use curl to test HTTP endpoints, inspect headers, download a single object, or call APIs from scripts. It is especially useful for DevOps and troubleshooting.

Common Mistakes¶

• Forgetting -L when the URL redirects.
• Putting API tokens directly in shell history.
• Confusing response headers with response body output.

Quick Reference¶

curl https://example.com
curl -I https://example.com
curl --version

Related Guides¶

• curl examples
• curl HTTP headers explained
• curl POST Request Examples
• curl interview questions

Summary¶

The curl command is safest when you understand the target, choose the right option, and verify the result with a separate command.