Delegator.py is a simple library for dealing with subprocesses, inspired by both envoy and pexpect (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: |
.
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Basic run functionality:
>>> 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:
# 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:
>>> c.expect('Password:')
>>> c.send('PASSWORD')
>>> c.block()
Other functions:
>>> 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
$ pip install delegator.py
✨🍰✨