/kərl/
n. “Talk to the internet without a browser.”
cURL is a command-line tool and library (libcurl) for transferring data with URLs. It supports a vast array of protocols, including HTTP, HTTPS, FTP, SMTP, and more, making it a Swiss Army knife for internet communication and scripting.
At its core, cURL allows users to send requests to remote servers and retrieve responses. For example, curl https://example.com fetches the HTML of a web page, while curl -X POST -d "name=Chris" https://api.example.com/users can submit data to an API endpoint. This makes it invaluable for testing, automation, and interacting with REST APIs.
cURL is also scriptable and works in batch operations, allowing repeated requests or data fetching without manual intervention. It can handle authentication headers, cookies, and SSL certificates, bridging the gap between human-readable browsing and programmatic interactions.
Developers often pair cURL with JSON or XML responses to automate tasks, test endpoints, or debug network interactions. For example, extracting user data from an API or sending log files to a remote server can be accomplished seamlessly.
While simple in its basic form, cURL is powerful enough to act as a full-fledged HTTP client. It is available on most operating systems, embedded in scripts, CI/CD pipelines, and even used by SaaS platforms to test and integrate external services.
Understanding cURL equips anyone dealing with networking, web development, or automated workflows to interact with the internet directly, bypassing browsers and GUIs, providing precision and reproducibility for testing, troubleshooting, and data transfer.