Description:
------------
Calling "powershell" via "exec" hangs, when called in browser context.
The same call works on CLI.

Why is a prior echo'ing needed to get it working in the browser?

Issue solved with the workaround provided here:
http://www.php.net/manual/fr/function.exec.php#110617

Test script:
---------------
<?php
$output = array();
$return_code = 0;
// hangs in browser, but works on CLI
exec('powershell "New-Object -com WScript.Shell | Get-Member"', $output);
// works (in browser and on CLI)
//exec('echo . | powershell "New-Object -com WScript.Shell | Get-Member"', $output);

echo "<pre>";
foreach($output as $line) {
    echo $line . PHP_EOL;
}
echo "</pre>";