curl – URL Transfer Tool

curl is a command-line tool for transferring data using various network protocols. Supporting HTTP, HTTPS, FTP, and many more, curl is essential for testing APIs, downloading files, and automating web requests.

Key Features

• Protocol Support: HTTP, HTTPS, FTP, SFTP, and more
• Authentication: Basic, digest, OAuth support
• SSL/TLS: Secure connections
• Proxy Support: HTTP and SOCKS proxies
• Resume Downloads: Continue interrupted transfers

Installation

curl is typically pre-installed:

sudo apt install curl

Usage Examples

Common curl commands:

# Simple GET request
curl https://api.example.com/users

# POST JSON data
curl -X POST -H "Content-Type: application/json" \
  -d '{"name":"John"}' https://api.example.com/users

# Download file
curl -O https://example.com/file.zip

# Follow redirects
curl -L https://example.com

# With headers
curl -H "Authorization: Bearer token" https://api.example.com

# Silent with output
curl -s https://api.example.com | jq

Benefits

curl is indispensable for API testing and automation. Its extensive protocol support and scripting capabilities make it a universal network tool.

Download curl