Question

shell_exec and exec are not returning any content. I can’t figure out what’s wrong.

Here’s some code:

echo 'test: ';
$output = shell_exec('whoami');
var_export($output, TRUE);
echo PHP_EOL . '<br>' . PHP_EOL;

And here’s the source of the output

test 2: 
<br>

I do not have control over the host, but I believe they’re running SuPHP. According to phpinfo, safe_mode is off. Running whoami from SSH outputs the expected value.

I’m at a loss. Any idea how to debug this?

Answer 1

You’re never printing the $output variable. The var_export() call returns the content of the variable when you call it with a true second parameter, it does not print it directly.