因此,我一直在做一些研究,我一直试图拼凑一个函数,在PHP中生成一个有效的v4 UUID。这是我能做的最接近的事了。我对十六进制、十进制、二进制、PHP的位运算符之类的知识几乎一无所知。这个函数生成一个有效的v4 UUID,直到一个区域。v4 UUID的形式应该是:

xxxxx-xxxx-4xxx-yxxx-xx

y等于8,9,a或b,这就是函数失败的地方,因为它不符合这一点。

我希望在这方面比我更有知识的人能帮我一把,帮我修复这个函数,这样它就遵守了这个规则。

函数如下:

<?php

function gen_uuid() {
 $uuid = array(
  'time_low'  => 0,
  'time_mid'  => 0,
  'time_hi'  => 0,
  'clock_seq_hi' => 0,
  'clock_seq_low' => 0,
  'node'   => array()
 );
 
 $uuid['time_low'] = mt_rand(0, 0xffff) + (mt_rand(0, 0xffff) << 16);
 $uuid['time_mid'] = mt_rand(0, 0xffff);
 $uuid['time_hi'] = (4 << 12) | (mt_rand(0, 0x1000));
 $uuid['clock_seq_hi'] = (1 << 7) | (mt_rand(0, 128));
 $uuid['clock_seq_low'] = mt_rand(0, 255);
 
 for ($i = 0; $i < 6; $i++) {
  $uuid['node'][$i] = mt_rand(0, 255);
 }
 
 $uuid = sprintf('%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x',
  $uuid['time_low'],
  $uuid['time_mid'],
  $uuid['time_hi'],
  $uuid['clock_seq_hi'],
  $uuid['clock_seq_low'],
  $uuid['node'][0],
  $uuid['node'][1],
  $uuid['node'][2],
  $uuid['node'][3],
  $uuid['node'][4],
  $uuid['node'][5]
 );
 
 return $uuid;
}

?>

当前回答

如何使用mysql为您生成uuid ?

$conn = new mysqli($servername, $username, $password, $dbname, $port);

$query = 'SELECT UUID()';
echo $conn->query($query)->fetch_row()[0];

其他回答

从PHP手册上的注释来看,你可以这样使用:

function gen_uuid() {
    return sprintf( '%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
        // 32 bits for "time_low"
        mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ),

        // 16 bits for "time_mid"
        mt_rand( 0, 0xffff ),

        // 16 bits for "time_hi_and_version",
        // four most significant bits holds version number 4
        mt_rand( 0, 0x0fff ) | 0x4000,

        // 16 bits, 8 bits for "clk_seq_hi_res",
        // 8 bits for "clk_seq_low",
        // two most significant bits holds zero and one for variant DCE1.1
        mt_rand( 0, 0x3fff ) | 0x8000,

        // 48 bits for "node"
        mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff )
    );
}

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";

Jack的回答略有变化,以增加对PHP < 7的支持:

// Get an RFC-4122 compliant globaly unique identifier
function get_guid() {
    $data = PHP_MAJOR_VERSION < 7 ? openssl_random_pseudo_bytes(16) : random_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));
}

来自汤姆,http://www.php.net/manual/en/function.uniqid.php

$r = unpack('v*', fread(fopen('/dev/random', 'r'),16));
$uuid = sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
    $r[1], $r[2], $r[3], $r[4] & 0x0fff | 0x4000,
    $r[5] & 0x3fff | 0x8000, $r[6], $r[7], $r[8])

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