[Solved] Haiku equivalents for XDG base directories

Development
1

Apologies for reopening this discussion. I’ve read Folder Distinctions for Development but it didn’t fully enlighten me. I’m looking for a somewhat correct way to map XDG base directories onto Haiku for this little app I’m working on. Far as I can tell, app data should go somewhere under $HOME/config, but where exactly?

  • the Python interpreter saves its history file under $HOME/config/var, which seems to be the correct place for state data
  • Midnight Commander saves its config and history under $HOME/config/non-packaged/data (despite being packaged, go figure)

What would be an acceptable place for my own Python script to save its data without having to ask the Haiku API?

Edit: never mind, I see that nowadays Haiku correctly sets $XDG_DATA_HOME and company. I’ll just look at that first, then fall back on OS defaults.

2

The recommended way to find the correct directory is using the FindDirectory API:

The documentation also explains which directory should be used for which things.
The data directory is primarily meant for read-only data that comes packaged with an app and doesn’t change.
~/config is a read-only directory managed by packagefs,you can’t directly create new folders there and ~/config/data only exists if you have a application installed that puts something there.
Of course it’s wrong that Midnight Commander uses ~/config/non-packaged/data,that technically works because non-packaged is a writable path,but that path is meant for app data of non-packaged applications.
Settings and user data is usually stored at ~/config/settings which is the B_USER_SETTINGS_DIRECTORY.
Almost all applications put their settings and data there,also Midnight Commander,don’t know why it stores stuff both in ~/config/settings (where is should be) and ~/config/non-packaged/data (where it shouldn’t).

1 Like
3

Oops, edited my post before seeing your reply. Okay, ~/config/settings it is then! But then what about the XDG_* variables as set by Haiku?

4

Only some are set, and those that are are “just” set by finddir aswell in the startup stuff, finddir is the definitive truth and more granular than the xdg spec

5

I get it, but this is for a portable Python script that only needs to be mostly correct. At least more so than the average Linux app (see below). Here’s the code I arrived at:

def config_home() -> str:
	"""Get storage dir for user config files as per the XDG spec."""
	if os.getenv("XDG_CONFIG_HOME"):
		return os.getenv("XDG_CONFIG_HOME")
	elif sys.platform.startswith("haiku"):
		return os.path.join(os.getenv("HOME"), "config", "settings")
	else:
		return os.path.join(os.getenv("HOME"), ".config")

What confused me at first: on Linux, the ~/.local/ hierarchy corresponds to /usr/local (hence why it has bin/ and share/ subdirectories). Both are for permanent data like help text and licenses, not transitory stuff like a scratchpad file or whatever. But a lot of developers see they can write to ~/.local/share/ and misuse it. Then their apps get ported to Haiku.

Now on Haiku, the equivalent locations are ~/config/non-packaged/ and /system/non-packaged, respectively; $XDG_DATA_DIR correctly points to the former, and should be used the same way as on Linux.

Thanks again for everyone’s patience. Here’s to more apps that follow OS conventions correctly.

6

If you have a path for Haiku please just use finddir, it will give you the correct location. Stuff with hardcoded $HOME is definetely wrong. The whole point of this system is that these locations can change

Edit: To be clear, finddir is a commanline app you can call, passing it the same constants you would the C/C++ classes. This seems badly documented sadly :frowning:

7

finddir B_USER_SETTINGS_DIRECTORY (that’s the equivelant(?) of ~/config/settings, not sure how to pass this to python though, maybe @BiPolar has an idea there?

EDIT: plenty of examples on how this is used can be found at haikuports

Also, finddir -l will give you a full list of variables.

8

With subprocess.run() it’s easy enough. My script already makes heavy use of external programs:

def config_home() -> str:
	"""Get storage dir for user config files as per the XDG spec."""
	if os.getenv("XDG_CONFIG_HOME"):
		return str(os.getenv("XDG_CONFIG_HOME"))
	elif sys.platform.startswith("haiku"):
		result = subprocess.run(
			["finddir", "B_USER_SETTINGS_DIRECTORY"],
			capture_output=True)
		return result.stdout.decode()
	else:
		return os.path.join(str(os.getenv("HOME")), ".config")

And thanks for the finddir tip! That will come in handy when writing more Haiku-oriented code.

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