src/Mime.php

   1 <?php
   2 /**
   3  * MIME detection code.
   4  *
   5  * @todo Maybe we could try to use fileinfo module if loaded
   6  */
   7
   8 declare(strict_types=1);
   9
  10 namespace PhpMyAdmin;
  11
  12 use function chr;
  13 use function mb_strlen;
  14 use function str_starts_with;
  15
  16 /**
  17  * Handles mime type detection
  18  */
  19 class Mime
  20 {
  21     /**
  22      * Tries to detect MIME type of content.
  23      *
  24      * @param string $test First few bytes of content to use for detection
  25      */
  26     public static function detect(string $test): string
  27     {
  28         $len = mb_strlen($test);
  29         if ($len >= 2 && $test[0] === chr(0xff) && $test[1] === chr(0xd8)) {
  30             return 'image/jpeg';
  31         }
  32
  33         if ($len >= 3 && str_starts_with($test, 'GIF')) {
  34             return 'image/gif';
  35         }
  36
  37         if ($len >= 4 && str_starts_with($test, "\x89PNG")) {
  38             return 'image/png';
  39         }
  40
  41         return 'application/octet-stream';
  42     }
  43 }