Environment variables are not recognised in config files

[MurtadhaInit]

Basic information

zellij --version: zellij 0.37.1
stty size: 24 150
uname -av or ver(Windows): Darwin macbookpro.local 22.5.0 Darwin Kernel Version 22.5.0: Mon Apr 24 20:52:24 PDT 2023; root:xnu-8796.121.2~5/RELEASE_ARM64_T6000 arm64

List of programs you interact with as, PROGRAM --version: wezterm 20230408-112425-69ae8472

Further information
In short, having envrionment variables as values for configuration settings in config.kdl is problematic.
E.g. having this line:
default_shell $SHELL
Results in the following error message when opening zellij:

And using quotes around it like so:
default_shell "$SHELL"
Results in zellij running but with the prompt hanging like this:

You can't do much here except quit zellij.

Those issues don't occur when I set an absolute path like so:
default_shell "/opt/homebrew/bin/zsh"

The same thing happens for other options. For instance:
scrollback_editor "/opt/homebrew/bin/nvim"
This works. But this:
scrollback_editor $EDITOR
does not work. Even though the value of that env variable is set in zsh rc files to command -v nvim

This seems inconsistent with the documentation that mentions the default values for those options are as I typed above.
If I'm missing something or some notation that I should have used, please let me know.

[jaeheonji]

Hi, @MurtadhaInit

By default, zellij's config file does not support environments. (such as $SHELL, $EDITOR)

// Choose the path to the default shell that zellij will use for opening new panes
// Default: $SHELL
//
// default_shell "fish"

A comment in the config file means that if you don't set a specific shell, it will act as the default shell. That doesn't mean it supports $SHELL env.

And the PR of #2291 only contains the code to support env for layout files. Therefore, in order to apply this feature to the config file, we need to update the zellij-utils/src/kdl/mod.rs

[MurtadhaInit]

Thanks for the clarification @jaeheonji 🙂
I didn't know that was the case.

[steakhutzeee]

Hi, this change would have a great impact. Particularly for those who version control their dotfiles. Any chance there is an update about it?

Thanks!