Skill: arnarsson/curl-http (version 1.0.0)

--- name: curl-http description: Essential curl commands for HTTP requests, API testing, and file transfers. homepage: https://curl.se/ metadata: {"clawdbot":{"emoji":"🌐","requires":{"bins":["curl"]}}} --- # 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=[REDACTED_SECRET]" # POST JSON data curl -X POST https://api.example.com/users \ -H "Content-Type: application/json" \ -d '{"name":"John","email":"[REDACTED_SECRET]"}' # 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":"[REDACTED_SECRET]"}' ``` ## 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-[REDACTED_SECRET]" \ https://api.example.com # API key in URL curl "https://api.example.com?[REDACTED_SECRET]" ``` ## Advanced Features ### Timeouts & retries ```bash # Connection timeout (seconds) curl --connect-timeout 10 https://example.com # Max time for entire operation curl --max-time 30 https://example.com # Retry on failure curl --retry 3 https://example.com # Retry delay curl --retry 3 --retry-delay 5 https://example.com ``` ### Cookies ```bash # Send cookies curl -b "session=abc123" https://example.com # Save cookies to file curl -c cookies.txt https://example.com # Load cookies from file curl -b cookies.txt https://example.com # Both save and load curl -b cookies.txt -c cookies.txt https://example.com ``` ### Proxy ```bash # Use HTTP proxy curl -x http://proxy.example.com:8080 https://api.example.com # With proxy authentication curl -x http://proxy:8080 -U user:pass https://api.example.com # SOCKS proxy curl --socks5 127.0.0.1:1080 https://api.example.com ``` ### SSL/TLS ```bash # Ignore SSL certificate errors (not recommended for production) curl -k https://self-signed.example.com # Use specific SSL version curl --tlsv1.2 https://example.com # Use client certificate curl --cert client.crt --key client.key https://example.com # Show SSL handshake details curl -v https://example.com 2>&1 | grep -i ssl ``` ## Response Handling ### Output formatting ```bash # Silent mode (no progress bar) curl -s https://api.example.com # Show only HTTP status code curl -s -o /dev/null -w "%{http_code}" https://example.com # Custom output format curl -w "\nTime: %{time_total}s\nStatus: %{http_code}\n" \ https://example.com # Pretty print JSON (with jq) curl -s https://api.example.com | jq '.' ``` ### Range requests ```bash # Download specific byte range curl -r 0-1000 https://example.com/large-file.zip # Resume download curl -C - -O https://example.com/large-file.zip ``` ## File Operations ### Downloading files ```bash # Download file curl -O https://example.com/file.zip # Download with custom name curl -o myfile.zip https://example.com/file.zip # Download multiple files curl -O https://example.com/file1.zip \ -O https://example.com/file2.zip # Resume interrupted download curl -C - -O https://example.com/large-file.zip ``` ### Uploading files ```bash # FTP upload curl -T file.txt ftp://ftp.example.com/upload/ # HTTP PUT upload curl -T file.txt https://example.com/upload # Form file upload curl -F "file=@document.pdf" https://example.com/upload ``` ## Testing & Debugging ### API testing ```bash # Test REST API curl -X GET https://api.example.com/users curl -X GET https://api.example.com/users/1 curl -X POST https://api.example.com/users -d @user.json curl -X PUT https://api.example.com/users/1 -d @updated.json curl -X DELETE https://api.example.com/users/1 # Test with verbose output curl -v -X POST https://api.example.com/login \ -H "Content-Type: application/json" \ -d '{"username":"test","password":"pass"}' ``` ### Performance testing ```bash # Measure request time curl -w "Total time: %{time_total}s\n" https://example.com # Detailed timing curl -w "\nDNS: %{time_namelookup}s\nConnect: %{time_connect}s\nTLS: %{time_appconnect}s\nTransfer: %{time_starttransfer}s\nTotal: %{time_total}s\n" \ -o /dev/null -s https://example.com ``` ### Common debugging ```bash # Show request and response headers curl -v https://api.example.com # Trace request curl --trace-ascii trace.txt https://api.example.com # Include response headers in output curl -i https://api.example.com ``` ## Common Patterns **Quick JSON API test:** ```bash curl -s https://api.github.com/users/octocat | jq '{name, bio, followers}' ``` **Download with progress bar:** ```bash curl -# -O https://example.com/large-file.zip ``` **POST JSON and extract field:** ```bash curl -s -X POST https://api.example.com/login \ -H "Content-Type: application/json" \ -d '{"user":"test","pass":"secret"}' | jq -r '.token' ``` **Check if URL is accessible:** ```bash if curl -s --head --fail https://example.com > /dev/null; then echo "Site is up" else echo "Site is down" fi ``` **Parallel downloads:** ```bash for i in {1..10}; do curl -O https://example.com/file$i.jpg & done wait ``` ## Useful Flags - `-X`: HTTP method (GET, POST, PUT, DELETE, etc.) - `-d`: Data to send (POST/PUT) - `-H`: Custom header - `-o`: Output file - `-O`: Save with remote filename - `-L`: Follow redirects - `-i`: Include headers in output - `-I`: Headers only - `-v`: Verbose output - `-s`: Silent mode - `-S`: Show errors even in silent mode - `-f`: Fail silently on HTTP errors - `-k`: Insecure (ignore SSL) - `-u`: Basic authentication - `-F`: Multipart form data - `-b`: Send cookies - `-c`: Save cookies - `-w`: Custom output format ## Tips - Use `-s` in scripts to suppress progress bar - Combine `-sS` for silent but show errors - Use `-L` for redirects (e.g., shortened URLs) - Add `-v` for debugging - Use `jq` to process JSON responses - Save common requests as shell aliases or scripts - Use `--config` for complex reusable requests ## Documentation Official docs: https://curl.se/docs/ Manual: `man curl` HTTP methods: https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods


Security scan verdicts — ClawScan: clean | static analysis: clean | VirusTotal: clean | SkillSpector: suspicious (MEDIUM)