1  
   2  <?php
   3  $str = ''; /* Future string */
   4  $maxchar = 8; /* The maximum number of characters */
   5  $chars = str_shuffle('abcdef1234567890');
   6  $len = strlen($chars);
   7  for ($i = 0; $i < $maxchar; $i++)
   8  {
   9  	$str .= $chars[mt_rand(0, $len-1)];
  10  }
  11  print $str;
  12  ?>