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Fronteers 2008 »

Setting an environment variable for all your apps

In the New World Order, Linux apps should all store their user-specific data according to the FreeDesktop Base Directory specification, which in practice means that config details for myapp end up in $HOME/.config/myapp. All well and good. However, I don’t like having configuration stored in dotfiles; I like to be able to get at it more easily, so I want it in $HOME/Settings. The XDG spec provides for this: you set an environment variable XDG_CONFIG_HOME (which defaults to $HOME/.config) and then everything uses it. Great! But…where do I set this variable so that all the apps get it?

Some suggestions:

  • $HOME/.bashrc, $HOME/.bash_profile, $HOME/.profile — as far as I can tell, these aren’t run as part of the login process, so they’re no good. They get run when you start bash, which means when you first fire up a terminal.
  • $HOME/.gnomerc — gets run by gdm. Might be a Debianism, and doesn’t work if I change away from gdm a few months from now
  • $HOME/.xinitrc, $HOME/.xsession — get run if you’re in X but not if you’re running over SSH, and .xsession is a Debianism
  • /etc/xdg/user-dirs.conf — this will change it for all users on the machine, not just me
  • Something in PAM. Perhaps. It’s not clear what, though.
  • A file of my choice, which I then source from all of the above places. This is doable but seems stupid to me, and I’m bound to miss something.
  • Something else. This is where you come in; where am I meant to set the environment so that everything gets access to it?

Answers on a postcard…

This entry was posted on Sunday, August 3rd, 2008 at 8:01 pm and is filed under LazyWeb, Linux. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

18 Responses to “Setting an environment variable for all your apps”

  1. whatever

    Frank O'De
    9 minutes later

  2. Whoops - hit the button too quick there.

    Why don’t you just make a symbolic link - ln -s $HOME/.config $HOME/Settings

    Frank O'Dwyer
    11 minutes later

  3. Frank: that’s what I currently am doing. However, I ought to be able to set it correctly rather than working around the problem :)

    sil
    21 minutes later

  4. There ~/.xprofile, which is read by gdm.

    pclouds
    30 minutes later

  5. /etc/profile is the usual UNIX way to do this kind of thing - think it works on Linux too. It usually contains system wide defaults and (I think) should work regardless of whether you use X or ssh, as long as you’re not using some weird shell that ignores it. Worth a try anyhow.

    Frank O'Dwyer
    36 minutes later

  6. Frank: /etc/profile will set it for all users on the system, not just me; same problem as /etc/xdg.

    pclouds: I didn’t know about that, but it has the same problem as .xsession; it won’t work if I ssh in (or possibly if I switch to a different login manager).

    sil
    52 minutes later

  7. Well you could put some logic in there, e.g. within /etc/profile test for the existence of a file such as $HOME/.xdg_profile and include it if it exists.

    Or test if $HOME/Settings exists and set the variable if it does.

    Otherwise you’re possibly stuck with doing it in two places, once for ssh and once for X.

    Still think a symlink is the easiest way though :-)

    Frank O'Dwyer
    75 minutes later

  8. Put it in .config/FreeDesktop, of course! ;)

    Roberto
    3 hours later

  9. Roberto: you’re all comedy all the time, you are :-)

    sil
    3 hours later

  10. I think .bashrc is loaded whenever bash is started.. And the gdm startup is a bash script (or maybe you use a crappy distro that uses another shell for gdm? Maybe this shell has an equivalent file?) On a unix system, I’ll bet there’s a shell somewhere in starting mostly anything.

    Tester
    5 hours later 
  11. Tester: .bashrc isn't sourced as part of startup. I know this because I wrote

echo "I was called" >> $HOME/bash-startup

in .bashrc and reboted the machine; no bash-startup file was created.
    sil
    5 hours later

  12. You will find that ~/.profile is parsed when you login both via gdm (with almost all sessions managers too) and when you ssh in.

    Go ahead and try it:
    echo ”.profile was called” >> $HOME/bash-startup

    karl
    7 hours later

  13. I can confirm that ~/.profile is called when you log in - I use it to load the colour profile for my monitor, and so just after I log in first the screen does a noticeable colour shift.

    Michael Maclean
    22 hours later

  14. Michael Maclean: aha. Yes. It does get run. *After* your autostart applications are autostarted. Useful, I don’t think. :)

    sil
    24 hours later

  15. Well it doesn’t sound like there is any single clean way of accomplishing it at the mo then.

    You can get anything run before starting your session using ~/.dmrc ~/.xsession and ~/.profile.

    in ~/.dmrc
    [Desktop]
    Session=default

    in ~/.xsession (assuming your still using gnome)
    export XDG_CONFIG_HOME=$HOME/Settings
    gnome-session

    in ~/.profile add your XDG_CONFIG_HOME line to the end (or beginning) too. .profile wont be read till after things have autostarted, but that dont matter as the var is already exported in ~/.xsession. It is only there for when you open terminals/bash/dash.

    karl
    29 hours later

  16. Oh, I didn’t realise it was after the autostart apps. But then, I don’t have any :)

    Michael Maclean
    38 hours later

  17. CDE sources your profile at login if you set DTSOURCEPROFILE=true in ~/.dtprofile. It sounds like this is the behaviour you’re after.

    You could get this by creating a .xsession that starts
    #!/bin/bash –login

    Peter Oliver
    7 days later

  18. Did you ever find a solution to this elsewhere? I’m quite interested in this as well.

    Dennis Fisher
    4 weeks later

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