PHP Socket实例

<?phperror_reporting(E_ALL);echo "<h2>TCP/IP Connection</h2>\n";/* Get the port for the WWW service. */$service_port = getservbyname('www', 'tcp');/* Get the IP address for the target host. */$address = gethostbyname('www.example.com');/* Create a TCP/IP socket. */$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);if ($socket === false) {    echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";} else {    echo "OK.\n";}echo "Attempting to connect to '$address' on port '$service_port'...";$result = socket_connect($socket, $address, $service_port);if ($result === false) {    echo "socket_connect() failed.\nReason: ($result) " . socket_strerror(socket_last_error($socket)) . "\n";} else {    echo "OK.\n";}$in = "HEAD / HTTP/1.1\r\n";$in .= "Host: www.example.com\r\n";$in .= "Connection: Close\r\n\r\n";$out = '';echo "Sending HTTP HEAD request...";socket_write($socket, $in, strlen($in));echo "OK.\n";echo "Reading response:\n\n";$buf = 'This is my buffer.';if (false !== ($bytes = socket_recv($socket, $buf, 2048, MSG_WAITALL))) {    echo "Read $bytes bytes from socket_recv(). Closing socket...";} else {    echo "socket_recv() failed; reason: " . socket_strerror(socket_last_error($socket)) . "\n";}socket_close($socket);echo $buf . "\n";echo "OK.\n\n";?>