Web page that prints out the contents of most predefined variables in PHP.

echovars.php

header('Content-Type: text/plain');

function echoAll($a, $n) {
  if ($a) {
    echo join(PHP_EOL, array_map(function($key) use ($a, $n) {
      return $n . "['$key'] = '$a[$key]';";
    }, array_keys($a))), PHP_EOL;
  }
}

echoAll($_SERVER, '$_SERVER');
echoAll($_GET, '$_GET');
echoAll($_POST, '$_POST');
echoAll($_COOKIE, '$_COOKIE');
echoAll($_FILES, '$_FILES');
echoAll($_REQUEST, '$_REQUEST');
echoAll($_SESSION, '$_SESSION');
echoAll($_ENV, '$_ENV');

exit('DEBUGGING');