<?php 
/************* 
 *@l - length of random string 
 */  
 function generate_rand($l){  
   $c= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";  
   srand((double)microtime()*1000000);  
   for($i=0; $i<$l; $i++) {  
      $rand.= $c[rand()%strlen($c)];  
   }  
   return $rand;  
 }
?>

http://webdeveloperplus.com/php/21-really-useful-handy-php-code-snippets/

Useful snippets for php developers.

Generate a random string

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