https://github.com/digitalresistor/vrun

Adds Python's bin/Scripts directory to PATH before executing a command. Primarily used with Python virtual environments.
https://github.com/digitalresistor/vrun

python python-2 python-3 python-script virtualenv

Last synced: about 2 months ago
JSON representation

Adds Python's bin/Scripts directory to PATH before executing a command. Primarily used with Python virtual environments.

• Host: GitHub
• URL: https://github.com/digitalresistor/vrun
• Owner: digitalresistor
• License: isc
• Created: 2017-06-08T21:08:39.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2017-09-17T22:14:32.000Z (over 8 years ago)
• Last Synced: 2025-03-24T20:19:59.221Z (12 months ago)
• Topics: python, python-2, python-3, python-script, virtualenv
• Language: Python
• Homepage: https://github.com/bertjwregeer/vrun
• Size: 38.1 KB
• Stars: 4
• Watchers: 2
• Forks: 0
• Open Issues: 2
• Metadata Files:
  • Readme: README.rst
  • Changelog: CHANGES.rst
  • License: LICENSE

Awesome Lists containing this project

README

          
vrun

====

Adds Python's bin/Scripts directory to ``PATH`` before executing a command.

Primarily used with Python virtual environments.

Overview

--------

A small Python helper tool that will modify the ``PATH`` in the environment

before executing the executable provided as the first argument. This is useful

when programs expect certain binaries to be available in ``PATH`` so they can

execute them using ``os.popen()`` and friends or even for shell scripts that

are executing Python tools that one would prefer to not globally install.

Scripts may detect that vrun has been used by looking for the environment

variable ``VRUN_ACTIVATED`` which is set to ``1`` when run. It is not

recommended that script writers do this.

Use

---

On macOS/FreeBSD/Linux/Unix:

.. code::

    $ python3 -mvenv ./env/

    $ ./env/bin/pip install vrun

    $ ./env/bin/vrun /bin/bash -c 'echo $PATH'

On Windows:

.. code::

    C:\> python3.exe -mvenv env

    C:\> env\Scripts\pip.exe install vrun

    C:\> env\Scripts\vrun.exe python -c "import os; print(os.environ['PATH'])"

If for example there is a script that executes ``pip`` without explicitly

providing a PATH that includes a virtual environment the system installed

``pip`` may accidentally be invoked instead. With vrun the virtual environment

will come first in the search path and thus ``pip`` will be safely executed

within the context of the virtual environment.

Such as a shell script:

.. code::

    $ ./env/bin/vrun ./myscript.sh

Or executing a Windows batch script:

.. code::

    C:\> env\Scripts\vrun.exe script.bat

Command aliases

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

vrun allows you to define command aliases in a configuration file, either

``vrun.cfg``, ``vrun.ini`` or ``setup.cfg``.

These configuration files must contain at least a ``vrun`` section, then using standard ini format you may specify key/value pairs:

.. code::

    

    [vrun]

    python.version = python --version

    shell = /bin/bash

    echo = /bin/bash -c 'echo ${@}' _ {posargs} echo off the bare walls

Now you may run these commands using:

.. code::

    vrun python.version

Which will return something similar to:

.. code::

    Python 3.6.2

Then you can do positional argument interpolation:

.. code::

    vrun echo the soft voices

will output:

.. code::

    the soft voices echo off the bare walls

Interpolation

~~~~~~~~~~~~~

So long as the keyword ``{posargs}`` is stand-alone, and surrounded by spaces

(and not inside of a quoted segment) ``vrun`` will replace it with any

positonal arguments provided on the command line. If not positional arguments

are provided, it will remove the ``{posargs}`` placeholder and remove it as an

argument.

If there is no ``{posargs}`` provided in the command alias, all extra arguments

provided after the initial command will be passed as positional arguments.

Using the ``shell`` example from above, you may do:

.. code::

    vrun shell -c 'echo $PATH'

which will execute:

.. code::

    /bin/bash -c 'echo $PATH'

Within the virtual environment as expected. This can be useful to allow you to

predefine certain longer commands, but still allow the user on the fly on the

command line to add additional parameters as necessary.

vrun or vexec

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

vrun installs itself as both ``vrun`` and ``vexec``. The later may be typed

with the left hand only and is slightly faster to roll off the keyboard!

License

-------

Please see the `LICENSE

`_ file in the source

code repository