rnd

A nice function to generate a random string, using any character:

<?php
function generateRandStr($length){
      $randstr = "";
      for($i=0; $i<$length; $i++){
         $randnum = mt_rand(0,61);
         if($randnum < 10){
            $randstr .= chr($randnum+48);
         }else if($randnum < 36){
            $randstr .= chr($randnum+55);
         }else{
            $randstr .= chr($randnum+61);
         }
      }
      return $randstr;
   }
?>

Simply use:
generateRandStr(10);

Sample output: $%29zon(4f

<?php

$random_number = intval( "0" . rand(1,9) . rand(0,9) . rand(0,9) . rand(0,9) . rand(0,9) ); // random(ish) 5 digit int

$random_string = chr(rand(65,90)) . chr(rand(65,90)) . chr(rand(65,90)) . chr(rand(65,90)) . chr(rand(65,90)); // random(ish) 5 character string

?>

I thought this function (random color) might be of use to someone [to create and return a random hex for HTML colors]:

<?php
function get_random_color()
{
    for ($i = 0; $i<6; $i++)
    {
        $c .=  dechex(rand(0,15));
    }
    return "#$c";
}
?>

http://www.sitepoint.com/php-random-number-generator/
http://php.net/manual/en/function.rand.php