<?php
// connect and login to FTP server
$ftp_server = "ftp.example.com";
$ftp_conn = ftp_connect($ftp_server) or die("Could not connect to $ftp_server");
$login = ftp_login($ftp_conn, $ftp_username, $ftp_userpass);

// get system type
if ($type = ftp_systype($ftp_conn))
  {
  echo "System type is: $type";
  }
else
  {
  echo "Could not get system type.";
  }

// close connection
ftp_close($ftp_conn);
?>

System type is: UNIX