It's not at all easy to understand, nor easy to implement, nor does it have any tangible advantages.
It's one of these superfluous pseudo-standards that do nothing but add needless clutter. But gladly nobody seems to be using it anyway, I see only one directory in my ~/.local: vlc.
The first benefit is that it removes clutters from your $HOME.
The second benefit is that you can now manage and backup your settings in a sane way.
* ~/.config contains config files (should not be lost, but if lost you can recreate them);
* ~/.local contains user data files (save them often, never lose them for they are not replaceable);
* ~/.cache contains cached information (can be tmpfs mounted, you can delete it any time you want, no loss in functionality, you just lose some optimization);
* ~/.run is for temporary system files (must be tmpfs mounted or it must be cleaned during at shutdown or power on).
Luckily most of the apps used on Linux systems now use it, you are probably using Mac OS X.
All of your points are invalid for a simple reason:
Almost no software uses this fancy standard.
And for the backup-case: Whitelisting is usually a futile idea to begin with. Normally you'd prefer to backup the odd superfluous file rather than miss an important one.
Luckily most of the apps used on Linux systems now use it
My box is not a desktop, so that's probably the difference. I still find that scheme an atrocity.
When going to that length they could at least have settled for one directory (~/.appdata or whatever). Half-baked is the most polite description I can come up with.
> The first benefit is that it removes clutters from your $HOME.
Invisible clutter? That's a strange concept.
But the rest of your point indeed makes sense. It still is easier and probably comment to backup the whole $HOME. But those points you can see as a benefit, though not obvious.
As Rob mentions in his post, the more dotfiles there are in $HOME the slower path resolution for any subfiles becomes. How do we navigate to ./src? We open the directory and read all the entries until we find the one called "src". What happens if we encounter a morass of dotfiles beforehand? src takes a while to find. The clutter may be invisible to you, but it does gum up the works.
For what it's worth, most modern file systems (JFS, XFS, ext4, reiserfs, btrfs, ...) have logarithmic (or better) directory lookup times. This is achieved using hashes and b-trees (or even hash tables).
I consider it good practice to allow users to customize where your program creates files. I don't like $HOME to be the default dumping ground for anything I run.
A standard that uses environment variables means programs don't have to provide extra options for this customization (I've seen -f,--file , -c,--config and other variants). It allows for common code (libraries that implement the spec).
If you poke around for feature requests for various open source programs, you'll find XDG basedir compliance come up occasionally (moreso for CLI utils). I wouldn't say "nobody seems to be using it"; quick scan of my folders includes Chromium, uzbl, htop. Git's next release will be compliant too.
I don't particularly like dumping everything in home, but XDG is worse. Now, if I want to start over with a clean profile, there's a whole list of locations I have to zap. Spraying shit in three directories is worse than one.
my problem with that "one" directory is that i have to take care specifically to back it up. applications that at least use ~/.cache means i don't have to worry about backing up a bunch of useless stuff.
Consider a browser cache. /tmp is not guaranteed to be preserved between program invocations[1]. /var/tmp [2] might be a better place. /var/cache [3] is intended for exactly this kind of thing.
Unfortunately, it can be far more useful for an administrator in a multi-user setup to want user-specific caches in home directories. That way, you get all of the infrastructure for managing user data for free, like quotas.
Also note: if you're considering putting data into /tmp or /var/tmp, please honor the TMPDIR environment variable, if it is set[4].
> If you poke around for feature requests for various open source programs, you'll find XDG basedir compliance come up occasionally (moreso for CLI utils).
What fraction of those requests are by XDG advocates?
I ask because every standard comes with folks insisting that it be followed. While those folks claim to represent the interests of users, those requests are different.
I guess I should have said "a modern linux desktop environment." Are these shell boxes or desktops? In my experience the majority of propgrams that use this spec are gtk/qt programs.
PS Listing a kernel version does not really provide any information about your modern linux distro.
I am always pleasantly surprised when programs follow XDG. One notable example is the fish shell. Most shells put dotfiles in $HOME, like .bash_profile or .zshrc. Fish puts everything in .config/fish/.
Somehow .dotfiles work just fine under Windows :). As such they are somehow more "portable"
Emacs saves them under %USERPROFILE% - I have in there - .alice, .android, .easyhg, .eclipse, .gstreamer-0.10, .lighttable, .m2, .matplotlib, .... .VirtualBox, .zenmap
Also in "Application Data" - .emacs.d, .mc, .subversion
My point is - this system works somehow even under non-unixy systems.
True. I actually kinda like the Windows directory structure since Vista. If only the application devs would also follow the standard (hence the whole My Documents mess).
Incidentally, Emacs will use %UserProfile%\.emacs.d if you set %HOME% to %UserProfile%, which, as a UNIX user, I personally prefer for consistency. While not Emacs-specific, another trick I've found useful is that, on 64-bit Windows, you can open %SystemRoot%\System32\somefile in 32-bit Emacs iff you refer to it as %SystemRoot%\sysnative\somefile (the original path yields %SystemRoot%\SysWOW64\somefile).
You can create them in Windows Explorer with a little trick: type the name with a trailing dot. Entering ".vimrc." will save as ".vimrc", no trailing dot.
I would have preferred if it did not rely on environment variables since almost nobody sets them which means there will be untested code in applications implementing the specification.
I notice the $XDG_DATA_HOME environment variable isn't set in my Intrepid install. Maybe its set in later Ubuntu version.
But the value not being set for me means implies to me that it not being set is pretty common. Thus it seems like supporting this standard is going to involve supporting a fall-back of whatever you would do otherwise.
So I don't see "easy" at all but rather extra BS. Sorry.
From the spec: If $XDG_DATA_HOME is either not set or empty, a default equal to $HOME/.local/share should be used. Similarly there's a default (.config/) defined for XDG_CONFIG_HOME. So the fallback is well-defined rather than "whatever you would do otherwise".
Also, for my 2c, you should consider updating your Intrepid install if you at all can. It hasn't been supported for over two years, so it hasn't seen any security updates in that time. The Ubuntu do-release-upgrade system is pretty easy and reliable.
To be fair, that's how it works. They have default values when they're not set. These are for when you want to override them, e.g. to keep cache files local instead of over your net mounted home directory.
It's not at all easy to understand, nor easy to implement, nor does it have any tangible advantages.
It's one of these superfluous pseudo-standards that do nothing but add needless clutter. But gladly nobody seems to be using it anyway, I see only one directory in my ~/.local: vlc.