Question

We were working on a mobile version of our site.

Some programmers put up this code on our normal non-mobile page. The result was that our site started to perform very slowly and bug out.

I’m thinking that the new mobile page may have had some bad code that was creating the issues, but I wanted to know if the code snippit put on our existing pages was problematic.

Here is is:

<?php
$iphone = strpos($_SERVER['HTTP_USER_AGENT'],"iPhone");
$android = strpos($_SERVER['HTTP_USER_AGENT'],"Android");
$palmpre = strpos($_SERVER['HTTP_USER_AGENT'],"webOS");
$berry = strpos($_SERVER['HTTP_USER_AGENT'],"BlackBerry");
$ipod = strpos($_SERVER['HTTP_USER_AGENT'],"iPod");

if ($iphone || $android || $palmpre || $ipod || $berry == true)
{
header('Location: http://m.site.com/index.php?id='.$HTTP_GET_VARS["id"]);
//OR
//echo "<script>window.location='http://mobile.site.com'</script>";
}

Someone from our hosting company suggested that the code maybe should have ‘===’ instead of ‘==’ at the end of the if statement.

Does the code look problematic?

Thanks as always.

Answer 1

First of all, I reccomend you to re-write:

1. Avoid PHP to print HTML tags (alternate PHP syntax designed to solve this!)
2. Use a header redirect and a regex.

//this function just detects device:
function detect_dev(){
  $devices = array();
  $devices['iPhone'] = 'iPhone';
  $devices['Android'] = 'Android';
  // add more

  foreach ($devices as $device => $name){
    if (preg_match("/$device/", $_SERVER['HTTP_USER_AGENT']){
    //ok, dev detected, return it's name 
    return $name;
  }
}

function redirect_sp_dev(){
  $device = detect_dev();

  // If it's not empty(mean device detected), do redirect: 
  if (!$device){
    redirect('your url with $device var');
  }
}

Also, some other notes, your URL is bad because I see it, and I already know how to hack your site. Read about XSS.

Do not use $HTTP_GET_VARS.
Do not use $_REQUEST

Use $_GET or $_POST instead.

1. I recommend you to rewrite url via mod_rewrite. Do it. It’s easy.
2. DO NOT PUT everything into INDEX file.
3. Read about MVC and PHP