Cómo crear alfanumérico aleatorio en PHP
<?php
// online code for creating alphanumeric in php
// this will generate 6 charactor, you can create as many just change the 6 from code
$pass = substr(str_shuffle("0123456789abcdefghijklmnopqrstvwxyz"), 0, 6);
echo $pass;
//output : 17w2y8
?>
Mr. Samy