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 kno         


        

Answer 1

Platform independent solution:

function cmd_exists($command)
{
    if (\strtolower(\substr(PHP_OS, 0, 3)) === 'win')
    {
        $fp = \popen("where $command", "r");
        $result = \fgets($fp, 255);
        $exists = ! \preg_match('#Could not find files#', $result);
        \pclose($fp);   
    }
    else # non-Windows
    {
        $fp = \popen("which $command", "r");
        $result = \fgets($fp, 255);
        $exists = ! empty($result);
        \pclose($fp);
    }

    return $exists;
}