<?php
/**
 * Generate and return a random string
 *
 * The default string returned is 8 alphanumeric characters.
 *
 * The type of string returned can be changed with the "seeds" parameter.
 * Four types are - by default - available: alpha, numeric, alphanum and hexidec. 
 *
 * If the "seeds" parameter does not match one of the above, then the string
 * supplied is used.
 *
 * @author      Aidan Lister <aidan@php.net>
 * @version     2.1.0
 * @link        http://aidanlister.com/repos/v/function.str_rand.php
 * @param       int     $length  Length of string to be generated
 * @param       string  $seeds   Seeds string should be generated from
 */
function str_rand($length = 8, $seeds = 'alphanum')
{
    // Possible seeds
    $seedings['alpha']    = 'abcdefghijklmnopqrstuvwqyz';
    $seedings['numeric']  = '0123456789';
    $seedings['alphanum'] = 'abcdefghijklmnopqrstuvwqyz0123456789';
    $seedings['hexidec']  = '0123456789abcdef';

    // Choose seed
    if (isset($seedings[$seeds])) {
        $seeds = $seedings[$seeds];
    }

    // Seed generator
    list($usec, $sec) = explode(' ', microtime());
    $seed = (float) $sec + ((float) $usec * 100000);
    mt_srand($seed);

    // Generate
	$str = '';
	$seeds_count = strlen($seeds);
	for ($i = 0; $length > $i; $i++) {
		$str .= $seeds{mt_rand(0, $seeds_count - 1)};
	}

	return $str;
}

?>