Checks if the file name exists, if it does uses recursion to append the file name with a number that has not yet been used.

duplicate_fixer()

function duplicate_fixer($fname, $count = 0, $old_fname = null){
  if($count != 0){
    $boom = explode(".", $old_fname);
    $boom[count($boom)-2] = $boom[count($boom)-2].$count.".";
    $fname = implode($boom);
  }
  if(file_exists($fname)){
    if($count == 0) $old_fname = $fname;
    $count++;
    $fname = duplicate_fixer($fname, $count, $old_fname);
    return $fname;
  } else {
    return $fname;
  }
}