socket php

[Dascos]

Beh...devi prima connetterti al socket, poi scriverci il pacchetto e poi chiudere la connessione.
Un client dovrebbe fare queste cose:

$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if ($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: [url]www.example.com\r\n[/url]";
$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";
while ($out = socket_read($socket, 2048)) {
    echo $out;
}

echo "Closing socket...";
socket_close($socket);
echo "OK.\n\n"; 

più o meno...
Se invece vuoi usare proprio socket_sendto, dovresti comunque fare il bind

 $sh = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
    if (socket_bind($sh, '127.0.0.1', 4242)) {
        echo "Socket bound correctly";
    }
    $buf = 'Test Message';
    $len = strlen($buf);
    if (socket_sendto($sh, $buf, $len, 0x100, '192.168.0.2', 4242) !== false) {
        echo "Message sent correctly";
    }
    socket_close($sh);