Web proxy checker

# Check SOCKS4/SOCKS5/HTTP/HTTPS proxies with and without authentication. Format of proxies with authentication: proxy_user:proxy_pass@proxy_host:proxy_port. Format of proxies without authentication: proxy_host:proxy_port # Check for connect to the specified host:port. # Check for URL (using HTTP GET or POST requests). # Load and combine proxies without checking. # Multithreaded. # Handle redirects. # Download proxy lists from the web. # Customizable User Agent.