Using PHP pfsockopen() for Persistent Socket Connections

pfsockopen() opens a persistent network or Unix socket connection, behaving like fsockopen() but keeping the connection alive after the script finishes, effectively providing a long‑lived socket.

Parameter description

hostname : The remote host name; prepend ssl:// or tls:// for encrypted connections.

port : Port number; use -1 for protocols without a port (e.g., unix:// ).

errno : Variable that receives the system‑level error number if the connection fails.

errstr : Variable that receives the error message string.

timeout : Connection timeout in seconds (default taken from default_socket_timeout ).

The function returns a file handle that can be used with standard file functions such as fgets() , fwrite() , fclose() , etc.; on failure it returns FALSE .

Example

<?php
$host = gethostbyaddr($_SERVER['REMOTE_ADDR']);
$host = 'www.example.com';
$service_uri = '/cgi-bin/processACT';
$vars = 'code=22&act=TEST';

$header = "Host: $host\r\n";
$header .= "User-Agent: PHP Script\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($vars) . "\r\n";
$header .= "Connection: close\r\n\r\n";

$fp = pfsockopen("ssl://" . $host, 443, $errno, $errstr);
if (!$fp) {
    echo "$errstr ($errno)
\n";
    echo $fp;
} else {
    fputs($fp, "POST $service_uri HTTP/1.1\r\n");
    fputs($fp, $header . $vars);
    fwrite($fp, $out);
    while (!feof($fp)) {
        echo fgets($fp, 128);
    }
    fclose($fp);
}
?>

The script builds the request headers, opens a secure socket to the target host, sends a POST request with the defined variables, reads the response line by line, and finally closes the connection.