:mod:`VirtualMailManager` ---  Initialization code and some functions

=====================================================================

.. module:: VirtualMailManager

  :synopsis: Initialization code and some functions

.. moduleauthor:: Pascal Volk <neverseen@users.sourceforge.net>

.. toctree::

   :maxdepth: 2

When the VirtualMailManager module, or one of its sub modules, is imported,

the following actions will be performed:

  - :func:`locale.setlocale` (with :const:`locale.LC_ALL`) is called, to set

    :const:`ENCODING`

  - :func:`gettext.install` is called, to have 18N support.

Constants and data

------------------

.. data:: ENCODING

  The systems current character encoding, e.g. ``'UTF-8'`` or

  ``'ANSI_X3.4-1968'`` (aka ASCII).

Functions

---------

.. function:: ace2idna(domainname)

  Converts the idn domain name *domainname* into punycode.

  :param domainname: the domain-ace representation (``xn--…``)

  :type domainname: str

  :rtype: unicode

.. function:: check_domainname(domainname)

  Returns the validated domain name *domainname*.

  It also converts the name of the domain from IDN to ASCII, if necessary.

  :param domainname: the name of the domain

  :type domainname: :obj:`basestring`

  :rtype: str

  :raise VirtualMailManager.errors.VMMError: if the domain name is

    too long or doesn't look like a valid domain name (label.label.label).

.. function:: check_localpart(localpart)

  Returns the validated local-part *localpart* of an e-mail address.

  :param localpart: The local-part of an e-mail address.

  :type localpart: str

  :rtype: str

  :raise VirtualMailManager.errors.VMMError: if the local-part is too

    long or contains invalid characters.

.. function:: exec_ok(binary)

  Checks if the *binary* exists and if it is executable.

  :param binary: path to the binary

  :type binary: str

  :rtype: str

  :raise VirtualMailManager.errors.VMMError: if *binary* isn't a file

    or is not executable.

.. function:: expand_path(path)

  Expands paths, starting with ``.`` or ``~``, to an absolute path.

  :param path: Path to a file or directory

  :type path: str

  :rtype: str

.. function:: get_unicode(string)

  Converts `string` to `unicode`, if necessary.

  :param string: The string taht should be converted

  :type string: str

  :rtype: unicode

.. function:: idn2ascii(domainname)

  Converts the idn domain name *domainname* into punycode.

  :param domainname: the unicode representation of the domain name

  :type domainname: unicode

  :rtype: str

.. function:: is_dir(path)

  Checks if *path* is a directory.

  :param path: Path to a directory

  :type path: str

  :rtype: str

  :raise VirtualMailManager.errors.VMMError: if *path* is not a directory.

Examples

--------

  >>> from VirtualMailManager import *

  >>> ace2idna('xn--pypal-4ve.tld')

  u'p\u0430ypal.tld'

  >>> idn2ascii(u'öko.de')

  'xn--ko-eka.de'

  >>> check_domainname(u'pаypal.tld')

  'xn--pypal-4ve.tld'

  >>> check_localpart('john.doe')

  'john.doe'

  >>> exec_ok('usr/bin/vim')

  Traceback (most recent call last):

    File "<stdin>", line 1, in <module>

    File "./VirtualMailManager/__init__.py", line 93, in exec_ok

      NO_SUCH_BINARY)

  VirtualMailManager.errors.VMMError: 'usr/bin/vim' is not a file

  >>> exec_ok('/usr/bin/vim')

  '/usr/bin/vim'

  >>> expand_path('.')

  '/home/user/hg/vmm'

  >>> get_unicode('hello world')

  u'hello world'

  >>> is_dir('~/hg')

  '/home/user/hg'

  >>>