A function for generating a random password of whatever length you need. You don't get super-secure passwords from this but they certainly should be good enough for e.g. a "forgotten your password?" feature. To avoid generating passwords containing offensive words, vowels are excluded from the list of possible characters. To avoid confusing user…

generatePassword.php

<?php

  function generatePassword ($length = 8)
  {

    // start with a blank password
    $password = "";

    // define possible characters - any character in this string can be
    // picked for use in the password, so if you want to put vowels back in
    // or add special characters such as exclamation marks, this is where
    // you should do it
    $possible = "2346789bcdfghjkmnpqrtvwxyzBCDFGHJKLMNPQRTVWXYZ";

    // we refer to the length of $possible a few times, so let's grab it now
    $maxlength = strlen($possible);
  
    // check for length overflow and truncate if necessary
    if ($length > $maxlength) {
      $length = $maxlength;
    }
        
    // set up a counter for how many characters are in the password so far
    $i = 0; 
    
    // add random characters to $password until $length is reached
    while ($i < $length) { 

      // pick a random character from the possible ones
      $char = substr($possible, mt_rand(0, $maxlength-1), 1);
        
      // have we already used this character in $password?
      if (!strstr($password, $char)) { 
        // no, so it's OK to add it onto the end of whatever we've already got...
        $password .= $char;
        // ... and increase the counter by one
        $i++;
      }

    }

    // done!
    return $password;

  }

?>