curl-http

# curl - HTTP Client

Command-line tool for making HTTP requests and transferring data.

## Basic Requests

### GET requests
```bash
# Simple GET request
curl https://api.example.com

# Save output to file
curl https://example.com -o output.html
curl https://example.com/file.zip -O  # Use remote filename

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

# Show response headers
curl -i https://example.com

# Show only headers
curl -I https://example.com

# Verbose output (debugging)
curl -v https://example.com
```

### POST requests
```bash
# POST with data
curl -X POST https://api.example.com/users \
  -d "name=John&email=john@example.com"

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

# POST from file
curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d @data.json

# Form upload
curl -X POST https://api.example.com/upload \
  -F "file=@document.pdf" \
  -F "description=My document"
```

### Other HTTP methods
```bash
# PUT request
curl -X PUT https://api.example.com/users/1 \
  -H "Content-Type: application/json" \
  -d '{"name":"Jane"}'

# DELETE request
curl -X DELETE https://api.example.com/users/1

# PATCH request
curl -X PATCH https://api.example.com/users/1 \
  -H "Content-Type: application/json" \
  -d '{"email":"newemail@example.com"}'
```

## Headers & Authentication

### Custom headers
```bash
# Add custom header
curl -H "User-Agent: MyApp/1.0" https://example.com

# Multiple headers
curl -H "Accept: application/json" \
     -H "Authorization: Bearer token123" \
     https://api.example.com
```

### Authentication
```bash
# Basic auth
curl -u username:password https://api.example.com

# Bearer token
curl -H "Authorization: Bearer YOUR_TOKEN" \
  https://api.example.com

# API key in header
curl -H "X-API-Key: your_api_key" \
  https://api.example.com

# API key in URL
curl "https://api.example.com?api_key=your_key"...