Learn Curl - 10 Code Examples & CST Typing Practice Test
cURL is a command-line tool and library for transferring data with URLs. It supports a vast range of protocols (HTTP, HTTPS, FTP, SMTP, SFTP, etc.) and is widely used for API testing, automation, network debugging, and data transfers.
Learn CURL with Real Code Examples
Updated Nov 21, 2025
Explain
cURL lets you send HTTP requests and interact with remote servers directly from the terminal.
It supports uploading, downloading, authentication, cookies, headers, and more.
Used heavily in DevOps, backend development, API development, and networking.
Core Features
HTTP requests (GET, POST, PUT, DELETE, PATCH)
Custom headers and cookies
Sending and receiving data
Verbose and debug modes
FTP/FTPS/SFTP file operations
Basic Concepts Overview
URLs and protocols
HTTP methods
Headers and cookies
Uploads and downloads
Authentication
Project Structure
scripts/ - stored reusable curl scripts
certs/ - TLS certificates
logs/ - verbose request logs
data/ - payload JSON files
docs/ - API endpoints and notes
Building Workflow
Choose target URL
Add proper HTTP method
Attach headers or payload
Execute and debug with -v
Parse output with jq if needed
Difficulty Use Cases
Beginner: simple GET requests
Intermediate: authenticated APIs
Advanced: file uploads & forms
Expert: debugging TLS/proxy issues
Enterprise: integrating curl in CI pipelines
Comparisons
More versatile than wget
More low-level than Postman
More scriptable than GUI tools
Not as simplified as httpie
Most widely supported HTTP tool available
Versioning Timeline
1997 - First release
2000s - libcurl widely adopted
2010s - Huge security and TLS improvements
2020s - Still dominant in DevOps and APIs
Ongoing - Frequent releases and security fixes
Glossary
HTTP method: type of request
Header: custom metadata
Payload: request body
TLS: encryption layer
Verbose mode: prints request/response
Frequently Asked Questions about Curl
What is Curl?
cURL is a command-line tool and library for transferring data with URLs. It supports a vast range of protocols (HTTP, HTTPS, FTP, SMTP, SFTP, etc.) and is widely used for API testing, automation, network debugging, and data transfers.
What are the primary use cases for Curl?
Calling REST APIs. Downloading or uploading files. Testing authentication flows. Debugging servers with verbose network logs. Automating data transfers
What are the strengths of Curl?
Massive protocol support. Perfect for API testing. Works everywhere (Linux, macOS, Windows). Reliable and stable for decades. Zero dependencies for most OS installs
What are the limitations of Curl?
Verbose syntax for complex operations. Not a programming language. Hard to read multi-flag commands. Limited JSON parsing (needs jq). Not ideal for browser-style sessions
How can I practice Curl typing speed?
CodeSpeedTest offers 10+ real Curl code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.