How to retrieve PHP exec() error responses?

Question

Below is the command I tried executing, without success:

exec(\'ln -s \' . PLUGIN_DIR . \'/.htaccess \' . ABSPATH . \'/.htaccess\');

When y

Answer 1

This worked for me in several scenarios:

 ob_start();
 exec($cmd . " 2>&1", $output);
 $result = ob_get_contents();
 ob_end_clean();
 var_dump($output);

The space between " 2 is important