Random Unique ID Generator in PHP

random-uniqueid.php

<?php
    // with prefix
    $uniqueid = uniqid('prefixhere_');
    echo $uniqueid;
    /* prints
    prefixhere_594f60936a7e9
    */  

    // with more entropy
   $uniqueid_2 = uniqid('',true);
   echo $uniqueid_2;
    /* prints
    594f60b9819a19.45879433
    */  

    // prefix + entropy
   $uniqueid_3 = uniqid('prefixand_',true);
   echo $uniqueid_3;
    /* prints
    prefixand_594f60d83cda14.54121719
    */
?>