php 两种短网址生成方法

 1 <?php
 2 
 3 
 4 //生成短网址方法1
 5 function shortUrl1($url)
 6 {
 7     if (empty($url)) {
 8         return FALSE;
 9     }
10     $url   = crc32($url);
11     $crc32 = sprintf("%u", $url);
12     $show  = ‘‘;
13     while ($crc32 > 0) {
14         $s = $crc32 % 62;
15         if ($s > 35) {
16             $s = chr($s + 61);
17         } elseif ($s > 9 && $s <= 35) {
18             $s = chr($s + 55);
19         }
20         $show .= $s;
21         $x = floor($crc32 / 62);
22     }
23     return $show;
24 }
25 
26 echo shorturl2(‘http://www.google.com/‘);
27 //4whP54
28 
29 //生成短网址方法2
30 function shortUrl2($input)
31 {
32     $base32 = array(
33         ‘a‘, ‘b‘, ‘c‘, ‘d‘, ‘e‘, ‘f‘, ‘g‘, ‘h‘,
34         ‘i‘, ‘j‘, ‘k‘, ‘l‘, ‘m‘, ‘n‘, ‘o‘, ‘p‘,
35         ‘q‘, ‘r‘, ‘s‘, ‘t‘, ‘u‘, ‘v‘, ‘w‘, ‘x‘,
36         ‘y‘, ‘z‘, ‘0‘, ‘1‘, ‘2‘, ‘3‘, ‘4‘, ‘5‘
37     );
38 
39     $hex       = md5($input);
40     $hexLen    = strlen($hex);
41     $subHexLen = $hexLen / 8;
42     $output    = array();
43     for ($i = 0; $i < $subHexLen; $i++) {
44         // 把加密字符按照8位一组16进制与0x3FFFFFFF(30位1)进行位与运算
45         $subHex = substr($hex, $i * 8, 8);
46         $int    = 0x3FFFFFFF & (1 * (‘0x‘ . $subHex));
47         $out    = ‘‘;
48         for ($j = 0; $j < 6; $j++) {
49             // 把得到的值与0x0000001F进行位与运算，取得字符数组chars索引
50             $val = 0x0000001F & $int;
51             $out .= $base32[$val];
52             $int = $int >> 5;
53         }
54         $output[] = $out;
55     }
56     return $output;
57 }
58 
59 $input = ‘http://www.google.com/‘;
60 
61 $output = shorturl($input);
62 var_dump($output);