.. -*- mode: rst -*-

========

 Opster

========

Opster is a command line options parser, intended to make writing command line

applications easy and painless. It uses built-in Python types (lists,

dictionaries, etc) to define options, which makes configuration clear and

concise. Additionally it contains possibility to handle subcommands (i.e.

``hg commit`` or ``svn update``).

Quick example

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

That's an example of an option definition::

  import sys

  from opster import command

  @command(usage='%name [-n] MESSAGE')

  def main(message,

           no_newline=('n', False, 'don\'t print a newline')):

      'Simple echo program'

      sys.stdout.write(message)

      if not no_newline:

          sys.stdout.write('\n')

  if __name__ == '__main__':

      main()

Running this program will print the help::

  echo.py [-n] MESSAGE

  Simple echo program

  options:

   -n --no-newline  don't print a newline

   -h --help        show help

As you can see, here we have defined option to not print newline: keyword

argument name is a long name for option, default value is a 3-tuple, containing

short name for an option (can be empty), default value (on base of which

processing is applied - `see description`_) and a help string.

Underscores in long names are converted into dashes.

If you are calling a command with option using long name, you can supply it

partially. In this case it could look like ``./echo.py --nonew``. This is also

true for subcommands: read about them and everything else you'd like to know in

`documentation`_.

.. _documentation: http://hg.piranha.org.ua/opster/docs/

.. _see description: http://hg.piranha.org.ua/opster/docs/overview.html#options-processing

Plans

-----

 - Better documentation

 - (under consideration) ability to have few command collectors in a single

   application (more than one dispatching entry point)