curl · wget Practical Guide — API Testing and File Downloads

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

# Pretty-print the response (paired with jq)
curl -s https://api.github.com/users/octocat | jq '.'

# Status code only
curl -o /dev/null -s -w "%{http_code}" https://example.com

# Verbose output (including headers)
curl -v https://example.com

# Headers only
curl -I https://example.com

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

# Timeouts
curl --connect-timeout 5 --max-time 30 https://example.com

# POST — JSON body
curl -X POST https://api.example.com/users   -H "Content-Type: application/json"   -d '{"name":"Alice","email":"alice@example.com"}'

# PUT
curl -X PUT https://api.example.com/users/1   -H "Content-Type: application/json"   -d '{"name":"Alice Updated"}'

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

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

# Multiple headers
curl https://api.example.com   -H "Accept: application/json"   -H "X-Request-ID: abc123"   -H "User-Agent: MyScript/1.0"

# Bearer token
curl -H "Authorization: Bearer eyJhbGci..." https://api.example.com/me

# Basic Auth
curl -u username:password https://api.example.com
# or
curl -H "Authorization: Basic $(echo -n user:pass | base64)" https://api.example.com

# API key
curl -H "X-API-Key: your-api-key" https://api.example.com

# Cookies
curl -b "session=abc123; token=xyz" https://example.com

# Save and send cookies
curl -c cookies.txt https://example.com/login -d "user=admin&pass=1234"
curl -b cookies.txt https://example.com/dashboard

# Form file upload (multipart)
curl -F "file=@/path/to/file.pdf" https://api.example.com/upload
curl -F "file=@image.jpg;type=image/jpeg" -F "name=profile" https://example.com

# Raw binary data
curl -X PUT --data-binary @file.tar.gz https://example.com/upload

# Save file (-O: original filename, -o: specified filename)
curl -O https://example.com/file.tar.gz
curl -o myfile.tar.gz https://example.com/file.tar.gz

# Show progress
curl -# -O https://example.com/large-file.iso

# Resume (interrupted download)
curl -C - -O https://example.com/large-file.iso

# Parallel downloads (with xargs)
cat urls.txt | xargs -n1 -P4 curl -O

# Download a file
wget https://example.com/file.tar.gz

# Resume download
wget -c https://example.com/large-file.iso

# Quiet (no progress)
wget -q https://example.com/file.tar.gz

# Number of retries
wget --tries=5 https://example.com/file.tar.gz

# Save under a specific filename
wget -O myfile.tar.gz https://example.com/file

# Recursive download (site mirroring)
wget -r -np -nH --cut-dirs=1 https://example.com/docs/

# Specific file types only
wget -r -A "*.pdf" https://example.com/papers/