doggie-radio-ui/radio.php

<?php
  if (isset($_POST['radio'])) {
    radioControl($_POST['radio']);
  }

  function radioControl($digit) {
    switch ($digit) {
      case '1':
        shell_exec('mpc play 1');
        break;
      case '2':
        shell_exec('mpc play 2');
        break;
      case '3':
        shell_exec('mpc play 3');
        break;
      default:
        shell_exec('mpc stop');
        break;
    }
  }

?>