Delegator.py — Subprocesses for Humans 2.0
=======================================


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**Delegator.py** is a simple library for dealing with subprocesses, inspired
by both `envoy <https://github.com/kennethreitz/envoy>`_ and `pexpect <http://pexpect.readthedocs.io>`_ (in fact, it depends on it!).

This module features two main functions ``delegator.run()`` and ``delegator.chain()``. One runs commands, blocking or non-blocking, and the other runs a chain of commands, separated by the standard unix pipe operator: ``|``.

If you're interested in financially supporting Kenneth Reitz open source, consider `visiting this link <https://cash.me/$KennethReitz>`_. Your support helps tremendously with sustainability of motivation, as Open Source is no longer part of my day job.

Basic Usage
-----------

Basic run functionality:

.. code:: pycon

>>> c = delegator.run('ls')
>>> print c.out
README.rst delegator.py

>>> c = delegator.run('long-running-process', block=False)
>>> c.pid
35199
>>> c.block()
>>> c.return_code
0

Commands can be passed in as lists as well (e.g. ``['ls', '-lrt']``), for parameterization.

Basic chain functionality:

.. code:: pycon

# Can also be called with ([['fortune'], ['cowsay']]).
# or, delegator.run('fortune').pipe('cowsay')

>>> c = delegator.chain('fortune | cowsay')
>>> print c.out
_______________________________________
/ Our swords shall play the orators for \
| us. |
| |
\ -- Christopher Marlowe /
---------------------------------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||


Expect functionality is built-in too, on non-blocking commands:

.. code:: pycon

>>> c.expect('Password:')
>>> c.send('PASSWORD')
>>> c.block()

Other functions:

.. code:: pycon

>>> c.kill()
>>> c.send('SIGTERM', signal=True)

# Only available when block=True, otherwise, use c.out.
>>> c.err
''

# Direct access to pipes.
>>> c.std_err
<open file '<fdopen>', mode 'rU' at 0x10a5351e0>

# Adjust environment variables for the command (existing will be overwritten).
>>> c = delegator.chain('env | grep NEWENV', env={'NEWENV': 'FOO_BAR'})
>>> c.out
NEWENV=FOO_BAR



Installation
------------

::

$ pip install delegator.py

✨🍰✨