Execution of DalekJS with PHP does not work - php

Question

I use the testing framework DalekJS to test the user interface. To execute my testing script mytest.js I type into the shell:
cd /Applications/XAMPP/xamppfiles/htdocs/tests
dalek mytest.js
and it works fine. Now I would like to execute the same script with PHP. My code:
<?php
chdir('/Applications/XAMPP/xamppfiles/htdocs/tests');
$command = 'dalek mytest.js';
exec($command, $return, $return_var);
var_dump($return);
var_dump($return_var);
Running my PHP-script in browser, it prints:
array(0) { } int(127)
The DalekJS script generates a screenshot when executing in shell but running with PHP it does not happen anything. I have also tried shell_exec(), system() and passthru() without success.
Do you have any idea why the PHP script does not work?

Answer 1

Calling dalek from PHP works fine for me. Is it possible your PHP process is running with a different environment (containing PATH, amongst other things) that your user? Maybe the apache user or some such?
<?php
// change current working directory of the current PHP process,
// this will subsequently change the initial CWD of exec()
$whereMyTestsAre = __DIR__;
chdir($whereMyTestsAre);
// locate dalek
$dalek = exec('which dalek');
// abort if there is no dalek,
// you may want to check PATH or supply the full path yourself
if (!$dalek) {
echo "could not find dalek executable, please check your path";
$PATH = exec('echo $PATH');
echo '$PATH is ', $PATH, "\n";
exit(1);
}
// relative to $whereMyTestsAre
// exec() blocks until the child process (dalek) exits
exec('dalek mytest.js');