Sanitize PHP filenames for UNIX/Linux

php-sanitize-filename

<?php

/**
 * Helper holds a collection of static methods, useful for generic purposes 
 */
class Helper
{
	/**
	 * Returns a safe filename, for a given platform (OS), by replacing all
	 * dangerous characters with an underscore.
	 *
	 * @param string $dangerous_filename The source filename to be "sanitized"
	 * @param string $platform The target OS
	 *
	 * @return Boolean string A safe version of the input filename
	 */
	public static function sanitizeFileName($dangerous_filename, $platform = 'Unix')
  	{
		if (in_array(strtolower($platform), array('unix', 'linux')) {
			// our list of "dangerous characters", add/remove characters if necessary
  			$dangerous_characters = array(" ", '"', "'", "&", "/", "\\", "?", "#");
  		}
  	  	else {
			// no OS matched? return the original filename then...
  	  	  	return $dangerous_filename;
  	  	}
  	
		// every forbidden character is replace by an underscore
		return str_replace($dangerous_characters, '_', $dangerous_filename);
  	}
}

// usage:
$safe_filename = Helper::sanitizeFileName('#my  unsaf&/file\name?"');

?>

As tqg5 said, you are missing a closing ")" on line 19