[basedir-spec] What exactly is $XDG_DATA_HOME for ?

[thibaut bethune]

2008/5/27 thibaut bethune <thibaut.bethune at gmail.com>:
> Reading that article (Cleaning user preferences, keeping user data)
> from Ploum at http://ploum.frimouvy.org/?184-cleaning-user-preferences-keeping-user-data,
> i've discovered basedir-spec (see comment 8 below the article).
>
> I thought that $XDG_CONFIG_HOME was for configuration files and that
> $XDG_DATA_HOME was for data. For instance, in the particular case of
> Transmission (a BitTorrent client http://www.transmissionbt.com/ )
> which creates several folders in home directory :
>    * $HOME/.transmission/cache/
>    * $HOME/.transmission/gtk/
>    * $HOME/.transmission/torrents/
>    * $HOME/.transmission/stats.bench
> and where $HOME/.transmission/torrents/ has information about files
> currently downloaded, i thought these informations were date that
> should be in $XDG_DATA_HOME.
> But Transmission developer (Charle at
> http://trac.transmissionbt.com/ticket/684 ) has understood (concerning
> files in $HOME/.transmission/torrents/ ) that "the intention of
> XDG_DATA_HOME vs XDG_CONFIG_HOME is that the former should only be
> written to when installing software. That way the directory is
> relatively constant, which makes backups easier for system
> administrators. By contrast, XDG_CONFIG_HOME is where all the
> frequently-changed or short-term files go. Given the short-term nature
> of .torrent files, IMO they're a better fit for XDG_CONFIG_HOME. They
> *definitely* aren't files written once when installing software."
>
> It seems that specs are not 100% clear about that and developers can't
> easily change their program to match these specs since it's hard to
> know which file must go in $XDG_DATA_HOME and which files must go
> $XDG_CONFIG_HOME. See http://bugzilla.gnome.org/show_bug.cgi?id=523057
> ans specially http://bugzilla.gnome.org/show_bug.cgi?id=518585#c3,
> http://bugzilla.gnome.org/show_bug.cgi?id=522848#c1 &
> http://bugzilla.gnome.org/show_bug.cgi?id=523174#c3
>
> 1°) Could you help us concerning transmission and files in
> $HOME/.transmission/torrents/ ?
> 2°) Maybe specs could be more precise or could have some exemples
> about which files are supposed to go to $XDG_DATA_HOME and which
> filesare supposed to go to $XDG_CONFIG_HOME ?
>
> Thanks !
>