Honor XDG variables on MacOS

[AntoinePrv]

Some MacOS users would like to use XDG configuration, especially for everything terminal related. Many tools out-there actually support it.

It would be great if dirs could honor these environment variables on MacOS too. I'm only talking of honoring the environment variables, not the default locations, so that this remains strictly opt-in.

Another way to make this even safer is to check an additional XDG_FORCE_MACOS environment variable. That way updating dirs will not break workflow of users that are already using XDG and ~/Library.

[soc]

Hi @AntoinePrv, please see dirs-dev/directories-rs#47 (comment).

[CGamesPlay]

This doesn't feel like a duplicate to me. In the linked issue, you mentioned that macOS has a standard location for these directories, and dirs uses those standard directories. That sounds completely reasonable.

However, this issue is about providing a user-facing customization hook hook for this (XDG environment variables), in particular one that plays nicely with customization hooks available on other platforms (which many of the consumers of this crate are compiling for as well). In particular, the linked comment gives an example: "add exclusions to macOS' backup software (Library/Caches is excluded, .cache isn't)". If the user is setting a custom XDG_CACHE_DIR, it's safe to assume they have added the exclusion mentioned.

Can you clarify your stance on why support for the environment variables should not be added to dirs?

[soc]

@CGamesPlay This library intends to implement the platform conventions as defined by the respective OS vendors, not what people want it to be.
The Apple documentation does not mention XDG_FORCE_MACOS.

[CGamesPlay]

Thanks for taking the time to respond!

[mortenscheel]

I know I probably won't change your mind, but I'll say it anyway: Those folder conventions you link to, are for GUI apps.
For CLI tools, even those that Apple provide out of the box, it's much more common that they follow UNIX conventions.

E.g. MacOS ships with zsh as the default shell. Its default configuration is in /etc/zshrc, and the default location for user-defined config is $HOME/.zshrc. If we follow your conventions, the config should be placed in /Users/{username}/Library/Application Support/zsh/.zshrc. But zsh won't look for a config file there (unless you create it manually and point ZDOTDIR at it). And it makes perfect sense for file paths that you'll usually edit from the terminal. Who in their right mind would use a path that includes whitespace for that?

Look, I'm not claiming that there is an official guideline similar to XDG for mac. But the vast majority of cli tools you can install via homebrew, use either $HOME/.{app-name} or $HOME/.config/{app-name}. The few that don't are all Rust tools that use your package to determine the location.

[soc]

The CLI tools are wrong and should fix their implementation.