curl HTTP headers Explained¶

Introduction¶

This article explains a common curl usage that administrators and learners often need to understand clearly.

What This Command Means¶

The command performs this specific task with curl:

curl -I https://example.com

Breaking Down the Command¶

• curl is the command being run.
• The options or arguments decide the behavior.
• The final value is the target, such as a file, process, service, package, host, URL, or directory.

Practical Examples¶

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

Example output:

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

When to Use It¶

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.

Safer Alternatives¶

Inspect before changing state when possible:

curl --version

For wider changes, test on a small target before using the command broadly.

Related Guides¶

• What is curl?
• curl examples
• curl POST Request Examples
• curl interview questions

Summary¶

Understanding curl HTTP headers is about knowing what each part does and checking the final state after running it.