Offers a way to save files as a cleaned, unique version of the original filename in symfony1

wfValidatedFileNamer

<?php

/**
 * Offers a way to save files as a cleaned, unique version of the original filename.
 *
 * Use this as the 'validated_file_class' option on sfValidatorFile.
 *
 * Bad characters are replaced by the replaceCharacter string. Unique filenames
 * are created by appending an increasing -# to the end of the basename
 * of the uploaded file.
 *
 * @author Ryan Weaver <ryan@thatsquality.com>
 */
class wfValidatedFileNamer extends sfValidatedFile
{
  /**
   * The "safe" character to replace bad characters within a filename
   *
   * @var string
   */
  public static $replaceCharacter = '-';

  /**
   * @see sfValidatedFile
   */
  public function generateFilename()
  {
    $cleanedName = $this->cleanFilename($this->getOriginalName());

    // if no file by the cleaned original name already exists, just return the originally uploaded filename
    if (!file_exists($this->getPath().'/'.$cleanedName))
    {
      return $cleanedName;
    }
    
    // iterate until we find a unique filename of format original_filename-n.ext where n is an integer
    $i = 1;
    while (1)
    {
      $basename = str_replace($this->getOriginalExtension(), '', $cleanedName);
      $newFilename = sprintf('%s-%s%s', $basename, $i, $this->getOriginalExtension());
      if (!file_exists($this->getPath().'/'.$newFilename))
      {
        return $newFilename;
      }
      $i++;
    }
  }

  /**
   * Removes non-filename safe characters and replaces them with a replace character
   *
   * Source http://iamcam.wordpress.com/2007/03/20/clean-file-names-using-php-preg_replace/
   *
   * @param  string $raw The raw filename
   * @return string A cleaned filename
   */
  protected function cleanFilename($raw)
  {
    // find and then remove all of the bad character
    $pattern="/([[:alnum:]_\.-]*)/";
    $cleaned = str_replace(str_split(preg_replace($pattern, self::$replaceCharacter, $raw)), self::$replaceCharacter, $raw);

    // remove duplicate $replace characters
    $pattern = '#('.preg_quote(self::$replaceCharacter).'){2,}#';

    return preg_replace($pattern, self::$replaceCharacter, $cleaned);
  }
}