cURL: The Swiss Army Knife of the Internet

Reference taken from: https://everything.curl.dev/

The Entry Point: Why cURL?

Browsers are black boxes that hide the raw conversation between the client and the server. Browsers request the server and wait for a response. Once it gets the response, returns it to the client.
cURL comes to the rescue; it is a lightweight tool to check the complete track of the request from the browser to the server and the returned response. cUrl stands for Client for URL. It behaves just like a “Postman” in your terminal; you send a request to the terminal, and cURL brings back the raw package.

The Basic Fetch (GET)

Suppose you want to check whether a website is successfully deployed or not, you can cURL a simple GET command to the domain, which will fetch and dump the complete HTML of the website to your terminal.
Run curl https://example.com to dump the HTML directly into your terminal.

Few more exciting commands includes:
curl ascii.live/forrest :- Create a illusion of a man running

curl wttr.in :- Give the weather update of your current location

Deep-Dive Debugging (Headers)

When something in the backend goes down, your application shows a blank page or a loading animation. You are unclear about what went wrong: did your server break, the logic break, or was it a Cloudflare issue?
Use cURL to inspect HTTP Headers—the hidden exchange of information (status codes, content types, and server metadata) that happens before the data arrives.
Use curl -I https://www.boxfarming.in to fetch only the headers; this tells you if the server is healthy (200 OK) or missing (404 Not Found) without downloading the whole page.

The "X-Ray" Mode: Use the -v (verbose) flag to see the entire handshake, including SSL certificates and the exact request your machine sent.

Few Flags :-

Flag	Name	The "Tool" Analogy	What it does
`-I`	Head	The X-Ray	Fetches only the Headers (Status codes, server info) without the body.
`-v`	Verbose	The Microscope	Shows the entire "conversation" (handshake, request, and response).
`-L`	Location	The Bloodhound	Automatically follows Redirects if the URL has moved.
`-o`	Output	The File Cabinet	Saves the server's response into a local file instead of printing to terminal.
`-d`	Data	The Envelope	Sends specific Data to the server (used primarily with POST).
`-H`	Header	The ID Badge	Adds extra information to your request (like API Keys or Content-Type).
`-k`	Insecure	The Master Key	Allows connections to local/dev servers with unverified SSL certificates.