PHP exec - check if enabled or disabled
ini_get('disable_functions')
What you actually want to do is use ini_get('disable_functions') to find out if it is available to you:
<?phpfunction exec_enabled() { $disabled = explode(',', ini_get('disable_functions')); return !in_array('exec', $disabled);}?>Answered on stackoverflow here: Check if "exec" is disabled, Which actually seems to come from the PHP Man page: http://php.net/manual/en/function.exec.php#97187
Path
If the above returns true (you can use exec()), but PHP can still not trigger the script there is a good chance that you have a path issue for that script, test this by doing:
print exec('which bash');and then try
print exec('which ogr2ogr');