>>> 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

# 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 |
                 ||     ||

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

>>> 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