:mod:`getpass` --- Portable password input

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

.. module:: getpass

   :synopsis: Portable reading of passwords and retrieval of the userid.

.. moduleauthor:: Piers Lauder <piers@cs.su.oz.au>

.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>

.. Windows (& Mac?) support by Guido van Rossum.

The :mod:`getpass` module provides two functions:

.. function:: getpass([prompt[, stream]])

   Prompt the user for a password without echoing.  The user is prompted using the

   string *prompt*, which defaults to ``'Password: '``. On Unix, the prompt is

   written to the file-like object *stream*.  *stream* defaults to the

   controlling terminal (/dev/tty) or if that is unavailable to ``sys.stderr``

   (this argument is ignored on Windows).

   If echo free input is unavailable getpass() falls back to printing

   a warning message to *stream* and reading from ``sys.stdin`` and

   issuing a :exc:`GetPassWarning`.

   Availability: Macintosh, Unix, Windows.

   .. versionchanged:: 2.5

      The *stream* parameter was added.

   .. versionchanged:: 2.6

      On Unix it defaults to using /dev/tty before falling back

      to ``sys.stdin`` and ``sys.stderr``.

   .. note::

      If you call getpass from within IDLE, the input may be done in the

      terminal you launched IDLE from rather than the idle window itself.

.. exception:: GetPassWarning

   A :exc:`UserWarning` subclass issued when password input may be echoed.

.. function:: getuser()

   Return the "login name" of the user. Availability: Unix, Windows.

   This function checks the environment variables :envvar:`LOGNAME`,

   :envvar:`USER`, :envvar:`LNAME` and :envvar:`USERNAME`, in order, and returns

   the value of the first one which is set to a non-empty string.  If none are set,

   the login name from the password database is returned on systems which support

   the :mod:`pwd` module, otherwise, an exception is raised.