将以下代码拿到 http://www.dooccn.com/php/ 运行, 得到UUID

    1. <?php
    2. function gen_uuid()
    3. {
    4.     return sprintf(
    5.         '%04x%04x%04x%04x%04x%04x%04x%04x',
    6.         // 32 bits for "time_low"
    7.         mt_rand(0, 0xffff),
    8.         mt_rand(0, 0xffff),
    10.         // 16 bits for "time_mid"
    11.         mt_rand(0, 0xffff),
    13.         // 16 bits for "time_hi_and_version",
    14.         // four most significant bits holds version number 4
    15.         mt_rand(0, 0x0fff) | 0x4000,
    17.         // 16 bits, 8 bits for "clk_seq_hi_res",
    18.         // 8 bits for "clk_seq_low",
    19.         // two most significant bits holds zero and one for variant DCE1.1
    20.         mt_rand(0, 0x3fff) | 0x8000,
    22.         // 48 bits for "node"
    23.         mt_rand(0, 0xffff),
    24.         mt_rand(0, 0xffff),
    25.         mt_rand(0, 0xffff)
    26.     );
    27. }
    28. for ($i = 0; $i < 100; $i++) {
    29.     echo gen_uuid().PHP_EOL;
    30. }