It sends a SITE command to the server
Example
<?php
$ftpId = ftp_connect(‘ftp.phpcodez.com’);
$login = ftp_login($ftpId, ‘anonymous’, ‘user@phpcodez.com’);
ftp_site($ftpId, ‘CHMOD 0775 /home/user/test -R’) or die(“Failed”);
ftp_quit($ftpId);
?>