def __init__(self, filename=None):
    """Create a sppasFileUtils instance.

    :param filename: (str) Name of the current file

    """
    self._filename = filename

def get_filename(self):
    """Return the current filename."""
    return self._filename

def set_random(self, root='sppas_tmp', add_today=True, add_pid=True):
    """Set randomly a basename, i.e. a filename without extension.

        :param root: (str) String to start the filename
        :param add_today: (bool) Add today's information to the filename
        :param add_pid: (bool) Add the process PID to the filename
        :returns: a random name of a non-existing file or directory

        """
    tempdir = tempfile.gettempdir()
    name = '/'
    while os.path.exists(name) is True:
        filename = root + '_'
        if add_today:
            today = str(date.today())
            filename = filename + today + '_'
        if add_pid:
            pid = str(os.getpid())
            filename = filename + pid + '_'
        filename = filename + '{:06d}'.format(int(random.random() * 999999))
        name = os.path.join(tempdir, filename)
    self._filename = name
    return name

def exists(self, directory=None):
    """Check if the file exists, or exists in a given directory.

        Case-insensitive test on all platforms.

        :param directory: (str) Optional directory to test if a file exists.
        :returns: the filename (including directory) or None

        """
    if directory is None:
        directory = os.path.dirname(self._filename)
    for x in os.listdir(directory):
        if os.path.basename(self._filename.lower()) == x.lower():
            return os.path.join(directory, x)
    return None

def clear_whitespace(self):
    """Set filename without whitespace.

        :returns: new filename with spaces replaced by underscores.

        """
    sp = sppasUnicode(self._filename)
    self._filename = sp.clear_whitespace()
    return self._filename

def to_ascii(self):
    """Set filename with only US-ASCII characters.

        :returns: new filename with non-ASCII chars replaced by underscores.

        """
    sp = sppasUnicode(self._filename)
    self._filename = sp.to_ascii()
    return self._filename

def format(self):
    """Set filename without whitespace and with only US-ASCII characters.

        :returns: new filename with non-ASCII characters and spaces        replaced by underscores.

        """
    self.clear_whitespace()
    self.to_ascii()
    return self._filename