编辑代码

<?php 

echo "<pre>";

/*生成唯一标志*标准的UUID格式为：xxxxxxxx-xxxx-xxxx-xxxxxx-xxxxxxxxxx(8-4-4-4-12)*/function  uuid()  
{  
    $chars = md5(uniqid(mt_rand(), true));  
    $uuid = substr ( $chars, 0, 8 ) . '-'
            . substr ( $chars, 8, 4 ) . '-' 
            . substr ( $chars, 12, 4 ) . '-'
            . substr ( $chars, 16, 4 ) . '-'
            . substr ( $chars, 20, 12 );  
    return $uuid ;  
}  
 
echo  uuid();  //Returns like 'dba5ce3e-430f-cf1f-8443-9b337cb5f7db'
echo "</pre>";

function generate_unique_id($prefix = '') {
    $microtime = microtime(true);
    $rand_num = mt_rand();
    $unique_id = uniqid($prefix, false);
    $hash = hash('sha256', $microtime . $rand_num . $unique_id);
    $uuid = substr ( $hash, 0, 8 ) . '-'
        . substr ( $hash, 8, 4 ) . '-' 
        . substr ( $hash, 12, 4 ) . '-'
        . substr ( $hash, 16, 4 ) . '-'
        . substr ( $hash, 20, 12 );  
    return substr($hash, 0, 32);
}

$unique_id = generate_unique_id('my_prefix_');
// 使用生成的唯一ID进行后续操作

echo $unique_id;