Parsing the User Agent String in PHP

JParra April 8'th 2008 03:00:45 pm

Recently I've been working on the stats logger of the blog and stumbled upon a typical WWW problem. The lack of standars, or more accurately the lack of browsers following standards, this time with the User Agent String.

I googled a bit and couldn't find the thing I was going after, the closest thing I found was this function on dotvoid.com, which is pretty limited to the goal I'm after.

So I decided to create a new user agent parser from the ground up, the  goal was to extract as much information as possible as simply as possible, the resulting code consist of 2 functions:


  1. 	function parse_useragent($agent){
  2. 		$parts = preg_split('/(?(?![^\(]*\))\s(?!\()|x{7})/', $agent);
  3. 		$data = array();
  4. 		foreach($parts as $key => $value){
  5. 			switch($key){
  6. 				case 0:
  7. 					list($data['product'], $comment) = explode(' (', $value);
  8.  
  9. 					$info = analyze_product_comment($comment);
  10. 				break;
  11. 				case 1:
  12. 					$data['engine'] = $value;
  13. 				break;
  14. 				case 2:
  15. 					if(stristr($value, 'version'))
  16. 						$data['engine'] .= " $value";
  17. 					else
  18. 						$data['browser'] = $value;
  19. 				break;
  20. 				case 3:
  21. 					$data['browser'] = $value;
  22. 				break;
  23. 				case 4:
  24. 					$data['browser'] = $value . " " .$parts[3];
  25. 				break;
  26. 			}
  27. 		}
  28. 		return $data+$info;
  29. 	}
  30. 	function analyze_product_comment($value){
  31. 		$value = str_ireplace(array("(", ")"), "", $value);
  32. 		$parts = explode("; ", $value);
  33. 		foreach($parts as $key => $val){
  34. 			switch($key){
  35. 				case 0:
  36. 					if(strtolower($val) == 'compatible'){//Usually IE or bots
  37. 						$info = array(
  38. 							'browser' => $parts[1],//Browser
  39. 							'os' => $parts[2]//OS
  40. 						);
  41. 						return $info;
  42. 					}
  43. 					$info['platform'] = $val;//Platform
  44. 				break;
  45. 				case 1:
  46. 					if(eregi('[uin]', $val))
  47. 						$info['security'] = $val;//Security
  48. 				break;
  49. 				case 2:
  50. 					$info['os'] = $val;//OS
  51. 				break;
  52.  
  53. 				case 3:
  54. 					if(eregi('[a-z\-]{2,6}', $val))
  55. 						$info['language'] = $val;//Language
  56. 				break;
  57. 			}
  58. 		}
  59. 		return $info;
  60. 	}

And you just use it by calling the parse_useragent function with the user agent as the first parameter.

Example: 

  1. $client = parse_useragent($_SERVER['HTTP_USER_AGENT']);
  2. print_r($client);
  3. /* Outputs
  4. array (
  5.   'product' => 'Mozilla/5.0',
  6.   'engine' => 'Gecko/2008032619',
  7.   'browser' => 'Firefox/3.0b5',
  8.   'platform' => 'Macintosh',
  9.   'security' => 'U',
  10.   'os' => 'Intel Mac OS X 10.5',
  11.   'language' => 'en-US',
  12. )
  13. */

Just a friendly reminder. All the code I post in here is licensed under an MIT License unless explicitly stated.

4 Comments Permalink Tags: php, stats, snippet