# include <cerrno>			// errno
# include <cstdio>			// perror
# include <sys/socket.h>	// socket, accept, listen, send, recv, bind, connect, setsockopt, getsockname

int	main()
{
	int server_fd;
	if (server_fd = socket(domain, type, protocol)
	{
		perror("cannot create socket");
		return 0;
	}
	return 0;
}