Why can I not return a GPIO's status from within a PHP 'if' statement?

[MeltingDog]

Hi all,

 

Sorry if this isnt the right place to ask this. I have tried many other forums and have had no luck.

 

I am learning programming for Raspberry Pi. Currently, I can read the output of a pin (GPIO) on the circuit board as such:

<?php 
exec ( "gpio read 7", $status );
print_r ( $status ); 
?>

That works fine - it prints the status to the screen.

 

However, if I put this in an 'if' statement, eg:

<?php
if (isset($_GET['trigger']) && $_GET['trigger'] == 1) {
exec ( "gpio read 7", $status );
print_r ( $status );
exec ( "gpio write 7 1" );
}
?>

It no longer works.

 

I know the if statement is correct as exec ( "gpio write 7 1" ); produces results.

 

Would anyone know what I have done wrong here or why I would not be able to read the status?

 

Many thanks in advance

[iarp]

Are you sure you're adding ?trigger=1 to the url? http://localhost/index.php?trigger=1

 

You may also need to use == '1' instead of just a plain 1, PHP is weird sometimes with comparisons.