How to check if a shell command exists from PHP

Question

I need something like this in php:

If (!command_exists('makemiracle')) {
  print 'no miracles';
  return FALSE;
}
else {
  // safely call the command knowing that it exists in the host system
  shell_exec('makemiracle');
}

Are there any solutions?

Answer 1

On Linux/Mac OS Try this:

function command_exist($cmd) {
    $return = shell_exec(sprintf("which %s", escapeshellarg($cmd)));
    return !empty($return);
}

Then use it in code:

if (!command_exist('makemiracle')) {
    print 'no miracles';
} else {
    shell_exec('makemiracle');
}

Update: As suggested by @camilo-martin you could simply use:

if (`which makemiracle`) {
    shell_exec('makemiracle');
}