How can I remotely shutdown a Raspberry PI from my network via a Web Interface?

Question

I am wondering how I could possibly input the values for option (e.g -r), time (e.g now) and message (e.g Shutting down), I have tried:

system("shutdown " . $option . "-t " . $time . " " . $message);

and that didn't work? (I am doing it via PHP, also.)

This is the code that I have so far in shutdown.php:

<?php 
$option = $_POST['option'];
$time = $_POST['time'];
$message = $_POST['message];
?>

I am using Apache 2 by the way.

• joan: The Pi is a general Linux box and is nothing special in this regard. Why not just have a shutdown script on the Pi (such as sudo shutdown -hP now) and just invoke the script?
• Connor: I'm not exactly a Linux genius :P , you might have to explain how I would go about doing such a thing
• joan: Login to the Pi (user pi presumably). Enter nano off. Add two lines, the first with #!/bin/bash, the second with sudo shutdown -hP now. Make it executable, chmod +x off. In your PHP use system("/home/pi/off")
• Connor: I've just executed it from my Mac on the same network and it's not shutting down?
• joan: There I can't help. I don't have an environment set-up to issue web commands to my Pi. Apache/PHP should log errors on the Pi somewhere.

Answer 1

You can't. Not without additional hardware.

There is no "off"-switch on the pi - when it's plugged in, it is powered.

You can put it in a runlevel that makes it disappear from the net, and you can reboot it.

The reason your php-script doesn't work, however, is probably that the user it is executing as does not have the rights to run the shutdown-command. This should show up in the /var/log/syslog-file.

• Connor: I mean shutdown - and how would I give the user the correct permissions?
• Ghanima: That is why joan suggested sudo shutdown.... So make sure the respective user has the right to sudo see en.wikipedia.org/wiki/Sudo There should be a special user that runs apache/php.