1: <?php
 2: /**
 3:  * Class for generating a 23-character random ID string. This string uses all
 4:  * characters in the class [-_0-9a-zA-Z].
 5:  *
 6:  * <code>
 7:  * $id = (string)new Horde_Support_Randomid();
 8:  * </code>
 9:  *
10:  * Copyright 2010-2012 Horde LLC (http://www.horde.org/)
11:  *
12:  * @author   Michael Slusarz <slusarz@horde.org>
13:  * @category Horde
14:  * @license  http://www.horde.org/licenses/bsd BSD
15:  * @package  Support
16:  */
17: class Horde_Support_Randomid
18: {
19:     /**
20:      * Generated ID.
21:      *
22:      * @var string
23:      */
24:     private $_id;
25: 
26:     /**
27:      * New random ID.
28:      */
29:     public function __construct()
30:     {
31:         $this->_id = $this->generate();
32:     }
33: 
34:     /**
35:      * Generate a random ID.
36:      */
37:     public function generate()
38:     {
39:         $pid = function_exists('zend_thread_id')
40:             ? zend_thread_id()
41:             : getmypid();
42: 
43:         /* Base64 can have /, +, and = characters. Restrict to URL-safe
44:          * characters. */
45:         return str_replace(
46:             array('/', '+', '='),
47:             array('-', '_', ''),
48:             base64_encode(
49:                 pack('II', mt_rand(), crc32(php_uname('n')))
50:                 . pack('H*', uniqid() . sprintf('%04s', dechex($pid)))));
51:     }
52: 
53:     /**
54:      * Cooerce to string.
55:      *
56:      * @return string  The random ID.
57:      */
58:     public function __toString()
59:     {
60:         return $this->_id;
61:     }
62: }
63: