Autoenv Trick




Sep 4, 2015

Firstly, if you haven't heard of autoenv then I suggest you go check it out now. Basically it allows you to run arbitrary shell scripts any time you enter a directory or any of its children, it's pretty useful.

You can do all sorts of things with this tool, though most people use it to configure their environment variables (hence the name). I use it for that as well, but I've added a new trick.

Basically, each time you enter a project it will try to join an existing tmux session for that project, if none exist it will create one.

Here's what's in each project's '.env' file now:

#!/bin/sh

# Echo the root folder of the current git repo.
gitroot(){
    echo `git rev-parse --show-toplevel`
}

# Reconnect tmux session
tmuxproj(){
# Don't attach to tmux if already in tmux
    if ! { [ "$TERM" = "screen" ] || [ -n "$TMUX" ]; } then
    # Attach to project tmux session if it exists, otherwise create it.
        tmux attach -t `gitroot` || tmux new -s `gitroot`
    fi
}

# inside a project's .env:
tmuxproj

I use vim with tmux extensively, and so I often set up a workplace with several tmux windows and splits. Setting all this up and remembering what I was working on every time I context switch can be a bit of a pain, so now I use autoenv to manage it for me. What would usually happen to me is that I'd set up a tmux session with all of this, then forget about it next time I went to work on this project, but now every time I enter a project's directory it automagically puts me back into the session.

Simple! Now I can't forget!

Hopefully you learned something 🤞! If you did, please consider checking out my book: It teaches the principles of using optics in Haskell and other functional programming languages and takes you all the way from an beginner to wizard in all types of optics! You can get it here. Every sale helps me justify more time writing blog posts like this one and helps me to continue writing educational functional programming content. Cheers!