Execute code to switch light on with PHP

I solved it.The answer was easy, indeed the user "http" was not allowed to execute things from the wiringpi library which the C-program needed to run.

In the end I simply did:

chmod +s action

(This sets modifies the executable (called "action") to always run with root privileges.)...and the code ran as expected with the following PHP file (index.php):

<?phpsystem('action 63 A off');?>

Thanks for all the help!

is the C program a binary that you can pass parameters to? If so the following should work.

string exec ( string $command [, array &$output [, int &$return_var ]] )

for example

exec("controller.exe {$data}",$output);

data being parameters to pass into the executable, and output being any response from the executable.

See here for an example

Considering echo exec('action') is working but not exec('action 63 A off') , it is seeming that the command is failing if there parameters .

If that is the case , why not make two shell scripts / batch files one for On and one for Off , and call those from PHP ?

File switch_on contents :

action 63 A on

File switch_off contents :

action 63 A off

Make sure switch_on and switch_off files are accessible by PHP and have Execute permission .

switch_on.php

<?php    exec('switch_on');?>

switch_off.php

<?php    exec('switch_off');?>