alexcouper / bash

Run bash commands from python

bash for python

A library that enables easy running and concatenation of bash commands in python

Installation

Install using pip:

pip install bash

Usage

Run commands as you would in bash:

>>> from bash import bash
>>> bash('ls . | grep ".pyc"')
bash.pyc
tests.pyc

Chain commands for the same effect:

>>> bash('ls . ').bash('grep ".pyc"')
bash.pyc
tests.pyc

This becomes increasingly useful if you later need to reuse one such command:

>>> b = bash('ls . ')
>>> b.bash('grep ".pyc"')
bash.pyc
tests.pyc
>>> b.bash('grep ".py$')
bash.py
tests.py

Access stdout and stderr attributes:

>>> b = bash('ls tests.py')
>>> b.stdout
'tests.py\n'
>>> b.stderr
''

Get the return code generated by a command:

>>> b = bash('ls tests.py')
>>> b
tests.py
>>> b.code
0

To get a stripped, unicode string version of bash.stdout call value():

>>> b = bash('ls tests.py').value()
u'tests.py'

Motivation

I found that I was often having to write the same lines of code to handle running bash commands from python.

This provides a pip-installable, tested shortcut to writing:

from subprocess import PIPE, Popen

p = Popen(cmd, shell=True, stdout=PIPE, stdin=PIPE, stderr=PIPE)
output, err = p.communicate()

Warning

Please note that this library uses shell=True under the hood. This means that this library is NOT suitable for running untrusted commands. (See explanation)

Running the tests

Simply use a test runner.

$ nosetests

Support + Contributing

Feel free to make pull requests, or report issues via the repo:

https://github.com/alexcouper/bash

bash's Issues

can I use this in python 3

I installed this by pip install bash.
After that I can Import bash in python 2.x using from bash import bashbut not in python3.

is there a way i can use this in python3?

Thanks!

Hi,And Some Question

Hi.I'm a Noob form China,And I really want to know what does this work.With only a popen() function?
So if the computer don't have a naive bash,it will can't use this?

The 'increasingly useful' case does not work

The 'increasingly useful' case in Readme.rst seems to show when we initialize bash object, it keeps the standard output as same input for all subsequent bash function calls. But it is not the case. Instead, each bash object initialization or bash function call will update the standard output as input for next bash call in a chain fashion.

Snippet from Readme.rst:
This becomes increasingly useful if you later need to reuse one such command::

>>> b = bash('ls . ')
>>> b.bash('grep ".pyc"')
bash.pyc
tests.pyc
>>> b.bash('grep ".py$"')
bash.py
tests.py

Actual Result:

>>> b = bash('ls tmp')
>>> b
a.txt
bash.py
bash.pyc
tests.py
tests.pyc
>>> b.bash('grep ".pyc"')
bash.pyc
tests.pyc
>>> b.bash('grep ".py$"')

[Note: The output is actually empty.]

code snippet:

    def sync(self, timeout=None):
        kwargs = {'input': self.stdout}  # 2. use previous stdout as input for next run
        if timeout:
            kwargs['timeout'] = timeout
            if not SUBPROCESS_HAS_TIMEOUT:
                raise ValueError(
                    "Timeout given but subprocess doesn't support it. "
                    "Install subprocess32 and try again."
                )
        self.stdout, self.stderr = self.p.communicate(**kwargs)  # 1. update self.stdout each run

Suggestion:
Revise this case in readme.

Some commands not enter into interactive mode

Hi,
first for all, I want to say GREAT THANKS YOU for cool, simple and elegant tool!
I've been looking for a long time way to rewrite some complex bash scripts in python, but every time I frustrated due missing simple and convenient way to use something cool things from bash like pipes and other things. Code on python in this case was bloated and inconvenient to write and use.

Your tool changed the things for me! Thank you!

About issue:
Some commands working well with interactive input.
E.g. next commends working well - it stops script :

• bash("sudo echo hello")
• bash("ssh user@server")

But by some reason next command not enter into interactive mode:

• bash("read answer")

In pure bash read answer working well.

I'm not strong in shell and terminal deep interaction mechanics, especially with python layer.
But I think these command use different mechanisms to enter to interactive mode.

Version of python bash package:

$ pip show bash 
Name: bash
Version: 0.6
...

License and updates

Hi Alex,

I would like to use the library in commercial settings (and I plan to extend it)
Can you please add License e.g. Apache 2.0?

Do you accept PR (it seems there are quite a lot of them submitted but not reviewed)

Thank you!

Ondra