So z.B.:
PHP-Code:
function sendPostToHost($strHost, $strPath, $strReferer, $strContentData) {
$fp = fsockopen($strHost, 80);
printf("Open!\n");
fputs($fp, "POST $strPath HTTP/1.1\n");
fputs($fp, "Host: $strHost\n");
fputs($fp, "Referer: $strReferer\n");
fputs($fp, "Content-type: application/x-www-form-urlencoded\n");
fputs($fp, "Content-length: ". strlen($strContentData) ."\n");
fputs($fp, "Connection: close\n\n");
fputs($fp, "$strContentData\n");
printf("Sent!\n");
fclose($fp);
return true;
}
Hier mal ein Beispiel für die Verwendung, aber nicht für schlecht programmierte Gästebücher missbrauchen ;-) 
PHP-Code:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>PHP - POST-Bot</title>
<style type="text/css">
.fontnormal { font-family: arial; color: #000000; font-weight: normal; text-decoration: none; font-size: 14px; }
A { font-family: arial; color: #000000; font-weight: normal; text-decoration: none; font-size: 14px; }
A:hover { font-family: arial; color: #000000; font-weight: normal; text-decoration: underline; font-size: 14px; }
TD { border: 1px solid #000000; padding: 5px; background-color: #EEEEEE; }
</style>
</head>
<body class="fontnormal">
<b>PHP - POST-Bot:</b><br><br>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
<span style="width: 120px;">Ziel-URL: </span><input type="text" name="targetDomain" value="" style="width: 300px;"> Bsp.: www.meinedomain.de<br />
<span style="width: 120px;">Ziel-Pfad: </span><input type="text" name="targetPath" value="/" style="width: 300px;"> Bsp.: /guestbook.php?do=show<br />
<span style="width: 120px;">Referer: </span><input type="text" name="referer" value="" style="width: 300px;"> Bsp.: www.meinabsender.de<br />
<span style="width: 120px;">Wiederholungen: </span><input type="text" name="countCalls" value="" style="width: 300px;"> Bsp.: 1000<br />
<span style="width: 120px; vertical-align: top; padding-top: 5px;">Daten: </span><textarea name="dataString" rows="5" cols="0" style="width: 300px;"></textarea> Bsp.: send=true&name=meinName<br />
<span style="width: 120px;"> </span><input type="submit" value="Starten" name="submit">
<input type="hidden" value="Suchen" name="submit">
</form>
<?php
function sendPostToHost($strHost, $strPath, $strReferer, $strContentData) {
$fp = fsockopen($strHost, 80);
printf("Open!\n");
fputs($fp, "POST $strPath HTTP/1.1\n");
fputs($fp, "Host: $strHost\n");
fputs($fp, "Referer: $strReferer\n");
fputs($fp, "Content-type: application/x-www-form-urlencoded\n");
fputs($fp, "Content-length: ". strlen($strContentData) ."\n");
fputs($fp, "Connection: close\n\n");
fputs($fp, "$strContentData\n");
printf("Sent!\n");
fclose($fp);
return true;
}
if (isset($_POST['submit'])) {
for ($i = 0; $i <= $_POST['countCalls']; $i++) {
sendPostToHost( $_POST['targetDomain'], $_POST['targetPath'], $_POST['referer'], $_POST['dataString']);
}
}
?>
</body>
</html>