PHP - Redirect based on OS optimization

Question

I'm new to PHP and I would like to redirect the visitors of my website based on their operating system. Below is my solution. Is there anything that needs to be optimized?

<?php
 // MOBILE
 $android = strpos($_SERVER['HTTP_USER_AGENT'],"Android");
 $blackberry = strpos($_SERVER['HTTP_USER_AGENT'],"BB10");
 $ios = strpos($_SERVER['HTTP_USER_AGENT'],"iOS");
 // DESKTOP
 $windows = strpos($_SERVER['HTTP_USER_AGENT'],"Windows");
 $mac = strpos($_SERVER['HTTP_USER_AGENT'],"Mac");
 // REDIRECTS 
 // MOBILE
 if ($android == true) 
 { 
 header('Location: http://www.example.com/android');
 } 
 else if ($blackberry == true) 
 { 
 header('Location: http://www.example.com/blackberry');
 }
 else if ($ios == true) 
 { 
 header('Location: http://www.example.com/ios');
 }
 // DESKTOP
 else if ($windows == true) 
 { 
 header('Location: http://www.example.com/windows');
 }
 else if ($mac == true) 
 { 
 header('Location: http://www.example.com/mac');
 }
 ?>

Thanks. Patrick

Answer 1

Before anything, I'll let you search on the web why this might not be such a good idea and I'll just focus on the code.

• You probably should retrieve $_SERVER['HTTP_USER_AGENT'] and store it in a variable in order to avoid repeated code. Also, you might want to check if the variable is set properly before accessing it to avoid warnings/errors.
• You can rewrite if ($variable == true) as if ($variable)
• You could avoid the boilerplate and repeated code if you were storing the interesting parts of your logic in an array and write the common parts only once :

 $ua = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';
 $redir = array(
 "Android" => 'android',
 "BB10" => 'blackberry',
 "iOS" => 'ios',
 "Windows" => 'windows',
 "Mac" => 'mac'
 );
 if (isset($redir[$ua]))
 {
 header('Location: http://www.example.com/' . $redir[$ua]);
 }

I hope this helps!

• Nic Wortel: I agree with Josay, this is not a good idea. You might want to look into responsive webdesign.