<?php
$URL="https://raw.githubusercontent.com/panticz/installit/master/install.proftpd.sh";

echo "wget $URL -O - | bash -";
echo "<div><pre>";
</pre></div>

$c = curl_init();
curl_setopt($c, CURLOPT_URL, $URL);
curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);

echo htmlspecialchars(curl_exec($c));

curl_close($c);

echo "";

?>

Create new ftp user
adduser ftp_user_1 -shell /bin/false -home /var/www/ftp_user_1/

# add ftp user to grup

adduser ftp_user_1 ftpuser

# clear user dir
rm /var/www/ftp_user_1/.*

Links
http://www.thomas-krenn.com/de/wiki/FTP-Server_unter_Debian_einrichten
http://www.debian-administration.org/article/228/Setting_up_an_FTP_server_on_Debian