Conform to XDG directory specification

I find that configuration and state data is stored in $HOME/.grip/, including (but not limited to) in these files:

• ~/.grip/cache-*

Users who do not expect state data to be stored here may accidentally back it up and synchronize it across systems improperly. Configuration data are fine, but prefer storing state data somewhere in $XDG_DATA_HOME and configuration data to $XDG_CONFIG_HOME to conform to the freedesktop.org / XDG standard.

Reference: https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html

$XDG_CONFIG_HOME defines the base directory relative to which user specific                                                                                                                                          
configuration files should be stored. If $XDG_CONFIG_HOME is either not set or                                                                                                                                       
empty, a default equal to $HOME/.config should be used.

$XDG_DATA_HOME defines the base directory relative to which user specific data                                                                                                                                       
files should be stored. If $XDG_DATA_HOME is either not set or empty, a default                                                                                                                                      
equal to $HOME/.local/share should be used.

To implement a painless migration for existing users, you can consider reading $XDG_CONFIG_HOME/grip/config.py first, then falling back to $HOME/.grip/. Likewise for cache data.

[alichtman]

I’d be in favor of maintaining backwards compatibility, and I do think following the XDG spec is important.

The important thing is to get rid of ~/.grip.

Agreed.

[denisfa]

If you are OK with it I can probably get a PR together that moves that to $XDG_CONFIG_HOME/grip but falls back if not found, like with the PR above

Sure! No problem! The important thing is to get rid of ~/.grip.

I’m not sure it’s necessary to force people to migrate. You can just implement the spec and then fall back to old behavior. See this PR for mypy: python/mypy#6304

Here is the thing. I think that since we are using a single config file settings.py, and the other files are cache, we could try to move straight to the spec. On some projects, the idea behind supporting legacy is to not break old installs (maybe giving users a time window too, but this is less relevant than the first) and be “nicer” to new ones. You would also need to set a future task with something like “remember removing legacy code after X months/versions”. No reason to keep multiple locations available after some time.

Edit: It would be a drawback to lose support for $GRIPHOME and it shouldn’t be necessary to lose that to implement the xdg spec

Here you need to be somewhat carefully. You can support the XDG with this like I did on my comment. But you would also change the expected behaviour if you allow this and change cache-* to $XDG_CACHE_HOME/grip. I also would like to know if someone is using this for something else other than supporting the XDG (or simply getting rid of ~/.grip).

Anyways, do as you wish. I really would like to help you more, but I am more busy now than I expected.