This is a quick tutorial on how to launch ZSH with a command already running, and drop to shell once it exits.

It can be any command, but I'm gonna use yazi - a terminal file manager - as an example.

The classic way would be zsh -c "yazi". This works, but the problem is that when you quit yazi, ZSH terminates. I want to drop to ZSH after I quit.

Another issue is that the command cannot be an alias. I have an yy alias for yazi. When I run yy, navigate to some directory, and then quit, ZSH changes directory to that one. This can't be done without an alias.

More promising method is this one:

zsh -i --nozle <<< "yazi; setopt zle"

It should drop to shell, and you could even use the yy alias.

This solution doesn't work for me though, giving me stty errors. After some debugging, I figured out it's caused by my prompt - OhMyPosh.

I would like a solution independent on whatever is in my .zshrc - be it prompt or whatever else.

Solution #

To the final solution then...

Add this to the end of your .zshrc:

unset ZSH_RUN_TMP
export ZSH_RUN_TMP="$ZSH_RUN"
unset ZSH_RUN
eval "$ZSH_RUN_TMP"

You can then launch ZSH with your new ZSH_RUN env:

ZSH_RUN="yy" zsh

It works great. yy is an alias, and changing directory as described above works as well.

The second ZSH_RUN_TMP variable fuckery is there so new shells launched from this one don't inherit your ZSH_RUN. Otherwise if you ran

ZSH_RUN="nvim" zsh

and then opened a new terminal from inside neovim, it would open a nested neovim session. Yikes.

Real use case #

I use foot as my terminal emulator. Foot can launch any shell or command like this:

foot bash
# or
foot zsh
# or
foot yazi

Well, now I have a keybind to execute this command:

ZSH_RUN="yy" foot zsh

It opens foot with yazi running, but I can exit yazi in any directory and drop to ZSH in it.

Source #

https://superuser.com/questions/91881/invoke-zsh-having-it-run-a-command-and-then-enter-interactive-mode-instead-of

Namely this comment, but improved.