灵感来自布鲁法的回答。

preg_replace_callback('/[xy]/', function ($matches)
{
  return dechex('x' == $matches[0] ? mt_rand(0, 15) : (mt_rand(0, 15) & 0x3 | 0x8));
}
, 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx');

或者如果无法使用匿名函数。

preg_replace_callback('/[xy]/', create_function(
  '$matches',
  'return dechex("x" == $matches[0] ? mt_rand(0, 15) : (mt_rand(0, 15) & 0x3 | 0x8));'
)
, 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx');

灵感来自布鲁法的回答。

preg_replace_callback('/[xy]/', function ($matches)
{
  return dechex('x' == $matches[0] ? mt_rand(0, 15) : (mt_rand(0, 15) & 0x3 | 0x8));
}
, 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx');

或者如果无法使用匿名函数。

preg_replace_callback('/[xy]/', create_function(
  '$matches',
  'return dechex("x" == $matches[0] ? mt_rand(0, 15) : (mt_rand(0, 15) & 0x3 | 0x8));'
)
, 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx');

在我搜索创建v4 uuid时，我首先来到了这个页面，然后在http://php.net/manual/en/function.com-create-guid.php上找到了这个页面

function guidv4()
{
    if (function_exists('com_create_guid') === true)
        return trim(com_create_guid(), '{}');

    $data = openssl_random_pseudo_bytes(16);
    $data[6] = chr(ord($data[6]) & 0x0f | 0x40); // set version to 0100
    $data[8] = chr(ord($data[8]) & 0x3f | 0x80); // set bits 6-7 to 10
    return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
}

信贷:pavel.volyntsev

编辑:澄清一下，这个函数总是给你一个v4 uuid (PHP >= 5.3.0)。

当com_create_guid函数可用时(通常仅在Windows上)，它将使用该函数并去掉花括号。

如果不存在(Linux)，它将使用强随机的openssl_random_pseudo_bytes函数，然后使用vsprintf将其格式化为v4 uuid。

为PHP >= 7加密安全UUID v4。

<?php

function uuid4() {
    /* 32 random HEX + space for 4 hyphens */
    $out = bin2hex(random_bytes(18));

    $out[8]  = "-";
    $out[13] = "-";
    $out[18] = "-";
    $out[23] = "-";

    /* UUID v4 */
    $out[14] = "4";
    
    /* variant 1 - 10xx */
    $out[19] = ["8", "9", "a", "b"][random_int(0, 3)];

    return $out;
}

echo uuid4();

输出:c68469d2 - 065 b - 4 - b17 b36f - 5 - c40efb5f6cd

我的答案是基于评论uniqid用户评论，但它使用openssl_random_pseudo_bytes函数来生成随机字符串，而不是从/dev/urandom读取

function guid()
{
    $randomString = openssl_random_pseudo_bytes(16);
    $time_low = bin2hex(substr($randomString, 0, 4));
    $time_mid = bin2hex(substr($randomString, 4, 2));
    $time_hi_and_version = bin2hex(substr($randomString, 6, 2));
    $clock_seq_hi_and_reserved = bin2hex(substr($randomString, 8, 2));
    $node = bin2hex(substr($randomString, 10, 6));

    /**
     * Set the four most significant bits (bits 12 through 15) of the
     * time_hi_and_version field to the 4-bit version number from
     * Section 4.1.3.
     * @see http://tools.ietf.org/html/rfc4122#section-4.1.3
    */
    $time_hi_and_version = hexdec($time_hi_and_version);
    $time_hi_and_version = $time_hi_and_version >> 4;
    $time_hi_and_version = $time_hi_and_version | 0x4000;

    /**
     * Set the two most significant bits (bits 6 and 7) of the
     * clock_seq_hi_and_reserved to zero and one, respectively.
     */
    $clock_seq_hi_and_reserved = hexdec($clock_seq_hi_and_reserved);
    $clock_seq_hi_and_reserved = $clock_seq_hi_and_reserved >> 2;
    $clock_seq_hi_and_reserved = $clock_seq_hi_and_reserved | 0x8000;

    return sprintf('%08s-%04s-%04x-%04x-%012s', $time_low, $time_mid, $time_hi_and_version, $clock_seq_hi_and_reserved, $node);
} // guid

这可以更简单吗?

$uuid = bin2hex(openssl_random_pseudo_bytes(16));
for($cnt = 8; $cnt <=23; $cnt+=5)
   $uuid = substr($uuid, 0, $cnt) . "-" . substr($uuid, $cnt);

echo $uuid . "\n";