php exec not executing if called from browser

Question

This is a recurring topic in stackoverflow, but finally I couldn't find any clear solution.

I'VE THIS PHP SCRIPT ON MY LOCAL XAMPP (OS X)

test.php

<?php exec('lpr -MyPrinter photos/image.jpg'); ?>

IT WORKS IF I CALL IT FROM TERMINAL

kurt$ php test.php

BUT IT DOES NOT WORK IF I CALL IT FROM BROWSER

http://localhost/mysite/test.php

Consider that my security requirements are very low, because I'll use this script locally only for personal purposes. Can you address me to the right solution?

Answer 1

Could have any number of reasons, but I suggest to look at the error message. The exec() function will not return it, but you can redirect error output to a temporary file:

<?php exec('lpr -MyPrinter photos/image.jpg 2> /tmp/error.txt'); ?>

Look into /tmp/error.txt after calling the script in the browser.