ANDROID AdBlock - PHP file for browser download

<?php
header("Content-Disposition: attachment; filename=adblock.sh");
header('Content-type: application/octet-stream');
?>
#!/bin/sh

mount -o remount,rw /system
A=$?

busybox wget -q http://winhelp2002.mvps.org/hosts.txt -O /etc/hosts
B=$?

mount -o remount,ro /system
C=$?

if [[ $A == 0 && $B == 0 && $C == 0 ]]; then
    echo "OK"
else
    echo "ERROR"
fi