PHP教程
//確保在連接客戶端時不會超時
set_time_limit(0);
//設置IP和端口號
$address = "127.0.0.1";
$port = 2048; //調試的時候,可以多換端口來測試程序!
/**
 * 創建一個SOCKET 
 * AF_INET=是ipv4 如果用ipv6,則參數為 AF_INET6
 * SOCK_STREAM為socket的tcp類型,如果是UDP則使用SOCK_DGRAM
*/
$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP) or die("socket_create() 失敗的原因是:" . socket_strerror(socket_last_error()) . "/n");
//阻塞模式
socket_set_block($sock) or die("socket_set_block() 失敗的原因是:" . socket_strerror(socket_last_error()) . "/n");
//綁定到socket端口
$result = socket_bind($sock, $address, $port) or die("socket_bind() 失敗的原因是:" . socket_strerror(socket_last_error()) . "/n");
//開始監聽
$result = socket_listen($sock, 4) or die("socket_listen() 失敗的原因是:" . socket_strerror(socket_last_error()) . "/n");
echo "OK\nBinding the socket on $address:$port ... ";
echo "OK\nNow ready to accept connections.\nListening on the socket ... \n";
do { // never stop the daemon
 //它接收連接請求并調用一個子連接Socket來處理客戶端和服務器間的信息
 $msgsock = socket_accept($sock) or die("socket_accept() failed: reason: " . socket_strerror(socket_last_error()) . "/n");
 
 //讀取客戶端數據
 echo "Read client data \n";
 //socket_read函數會一直讀取客戶端數據,直到遇見\n,\t或者\0字符.PHP腳本把這寫字符看做是輸入的結束符.
 $buf = socket_read($msgsock, 8192);
 echo "Received msg: $buf \n";
 
 //數據傳送 向客戶端寫入返回結果
 $msg = "welcome \n";
 socket_write($msgsock, $msg, strlen($msg)) or die("socket_write() failed: reason: " . socket_strerror(socket_last_error()) ."/n");
 //一旦輸出被返回到客戶端,父/子socket都應通過socket_close($msgsock)函數來終止
 socket_close($msgsock);
} while (true);
socket_close($sock);

PHP教程
set_time_limit(0);
$host = "127.0.0.1";
$port = 2048;
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)or die("Could not create  socket\n"); // 創建一個Socket
 
$connection = socket_connect($socket, $host, $port) or die("Could not connet server\n");  // 連接
socket_write($socket, "hello socket") or die("Write failed\n"); // 數據傳送 向服務器發送消息
while ($buff = @socket_read($socket, 1024, PHP_NORMAL_READ)) {
  echo("Response was:" . $buff . "\n");
}
socket_close($socket);