def is_special_file(cls, filename):
<EOL>if not os.path.exists(filename):<EOL><INDENT>return False<EOL><DEDENT>mode = os.stat(filename).st_mode<EOL>if stat.S_ISCHR(mode):<EOL><INDENT>return True<EOL><DEDENT>if stat.S_ISBLK(mode):<EOL><INDENT>return True<EOL><DEDENT>if stat.S_ISFIFO(mode):<EOL><INDENT>return True<EOL><DEDENT>if stat.S_ISSOCK(mode):<EOL><INDENT>return True<EOL><DEDENT>return False<EOL>
Checks to see if a file is a special UNIX file.

        It checks if the file is a character special device, block special
        device, FIFO, or socket.

        :param filename: Name of the file

        :returns: True if the file is a special file. False, if is not.