First: creat func.php file
<?php // tutorialspots.com function get_rand_id($length) { if($length>0) { $rand_id=""; for($i=1; $i<=$length; $i++) { mt_srand((double)microtime() * 1000000); $num = mt_rand(1,36); $rand_id .= assign_rand_value($num); } } return $rand_id; } function assign_rand_value($num) { // accepts 1 - 36 switch($num) { case "1": $rand_value = "a"; break; case "2": $rand_value = "b"; break; case "3": $rand_value = "c"; break; case "4": $rand_value = "d"; break; case "5": $rand_value = "e"; break; case "6": $rand_value = "f"; break; case "7": $rand_value = "g"; break; case "8": $rand_value = "h"; break; case "9": $rand_value = "i"; break; case "10": $rand_value = "j"; break; case "11": $rand_value = "k"; break; case "12": $rand_value = "l"; break; case "13": $rand_value = "m"; break; case "14": $rand_value = "n"; break; case "15": $rand_value = "o"; break; case "16": $rand_value = "p"; break; case "17": $rand_value = "q"; break; case "18": $rand_value = "r"; break; case "19": $rand_value = "s"; break; case "20": $rand_value = "t"; break; case "21": $rand_value = "u"; break; case "22": $rand_value = "v"; break; case "23": $rand_value = "w"; break; case "24": $rand_value = "x"; break; case "25": $rand_value = "y"; break; case "26": $rand_value = "z"; break; case "27": $rand_value = "0"; break; case "28": $rand_value = "1"; break; case "29": $rand_value = "2"; break; case "30": $rand_value = "3"; break; case "31": $rand_value = "4"; break; case "32": $rand_value = "5"; break; case "33": $rand_value = "6"; break; case "34": $rand_value = "7"; break; case "35": $rand_value = "8"; break; case "36": $rand_value = "9"; break; } return $rand_value; } ?>
Usage:
<?php include('func.php'); $length=15; echo get_rand_id($length); ?>
Result:
dd2djhiwgdpgzn9
n5ktlbi4roi6zhy
….
Alternative method, very short:
<?php /** * @author phptuts * @link http://tutorialspots.com/php-generate-random-ids-199.html */ function get_rand_id2($length, $chars = 'abcdefghijklmnopqrstuvwxyz0123456789') { if ($length > 0) { $rand_id = ""; for ($i = 1; $i <= $length; $i++) { mt_srand((double)microtime() * 1000000); $num = mt_rand(0, strlen($chars) - 1); $rand_id .= $chars{$num}; } } return $rand_id; } ?>