Set environment variable in current shell from child process

[peakschris]

Description of the new feature

We launch a python CLI from windows terminal. As a result of certain CLI actions, we want the windows terminal to set certain environment variables as soon as the python CLI command finishes. I understand that this is impossible when launching python from CMD. However, maybe there is some trick to allow it when launching python from Windows Terminal.

We have discarded the option of wrapping the python CLI in a bat or cmd as then we end up with the dreaded 'Terminate (Y/N)' prompt on Ctrl-C.

My hope is that Windows Terminal has some kind of scripting support such that the python subprocess can add an envvar in its parent shell via some kind of API call.

Any other ideas very welcome!

Proposed technical implementation details

No response

[PankajBhojwani]

Thank you for the request! Unfortunately Terminal does not have any special control over the environments of running processes.

Just curious - why do you want the environment variables in CMD while running Python /?

[peakschris]

So to be clear, I don't want terminal to change the environment of a running process. I want the running process to change the terminal's environment so that it will apply to any future commands that are invoked.

[peakschris]

Why? We have a python CLI that has multiple options. One of those is 'install devtools'. This creates a new bin directory in a new location. We want these tools to be available immediately after this CLI invocation is finished, without the developer needing to restart terminal. So we'd like the python CLI to be able to update the PATH envvar that the terminal will use for future commands.

[DHowett]

Ah, sorry about that.

Terminal automatically reloads the environment from the registry for every new pane and every new tab! That is, unless the user has disabled that feature by setting compatibility.reloadEnvironmentVariables to false (or toggled this setting in the Advanced settings page:

)

Even so, when I read...

the terminal will use for future commands

... I still can't help but think you want the currently running shell (pwsh.exe, cmd.exe, powershell.exe) to reload.

At the end of the day, it is still the shell which is running your commands. Any process that is already running when you update the environment--including the shell--is immune to those changes.

That's what we mean when we say "running process". 🙂

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To put it differently:

I understand that this is impossible when launching python from CMD. However, maybe there is some trick to allow it when launching python from Windows Terminal.

There is no dichotomy here: CMD is still running, it's just inside Terminal.