Correctly setting environment

Question

I'm using zsh and gdm to run gnome. Some time ago I discovered that variables are not set correctly. For example LANG/LC_ALL are incorrect ("" instead of en_GB.UTF-8).

I split the .zshrc into .zshrc and .profile. In the latter I set the environment variables, but how can I set the variables before the session starts? I tried a few choices (.xinitrc, .xsessionrc) but none seemed to work.

Edit To clarify - I used .profile and manually sourced it in .zshrc. It does not change question anyway.

Answer 1

The simple way is to invent a time machine, visit the various people who devised shell startup files and tell them to cleanly distinguish between three things:

• session setup, e.g. environment variables;
• session launching, i.e., e.g. starting a command-line shell or a window manager or running startx;
• shell initialization, e.g. aliases, prompt, key bindings.

It's not too hard to get session vs. shell right in a portable way: login-time initialization goes into .profile (or .zprofile, or .login), shell initialization goes in .bashrc or .zshrc. I've previously written about .bash_profile, zsh vs. other shells, more about portability (mostly about bash), more about who reads .profile.

A remaining problem is distinguishing between session setup and session launching. In most cases, ~/.profile is executed when you log in and can double as both, but there are exceptions:

• If your login shell is (t)csh or zsh, ~/.login and ~/.zprofile is sourced instead of ~/.profile. Ditto for bash and ~/.bash_profile, but this is easily solved by sourcing ~/.profile from ~/.bash_profile.
• If you log in under a display manager (xdm, gdm, kdm, …), whether your ~/.profile is read depends on the version of the program, on your distribution (Linux or otherwise), and on what session type you choose.
  • If you count on the display manager to start a session for you, your .profile must set environment variables but not start a session (e.g. a window manager).
  • The traditional configuration file for X sessions is ~/.xsession, doing both session setup and session launching. So the file can be essentially . ~/.xsession; . ~/.xinitrc. Some distributions source ~/.profile before ~/.xsession. Modern distributions only source ~/.xsession when you select a “custom” session from the display manager, and such a session is not always available.
  • Your session manager may have its own way of setting environment variables. (That's an optional part of your desktop environment, chosen by you through a configuration file or by selecting a session type when logging in; don't confuse it with the session startup scripts provided by the display manager, which are executed under your user but chosen on a system-wide basis. Yes, it's a mess.)

In summary, ~/.profile is the right place for environment variables. If it's not read, try sourcing it from ~/.xsession (and start your X programs from there), or look for a system-specific method (which may depend on your distribution, display manager if any, session type if display manager, and desktop environment or session manager).

Answer 2

In Gentoo documentation there is article Gentoo Linux Localization Guide. Chapter 3 is about setting locale.

Most typically users only set the LANG variable on the global basis. This example is for a unicode German locale:

Code Listing 3.1: Setting the default system locale in /etc/env.d/02locale

LANG="en_GB.UTF-8"

In my Gentoo LANG is set in this file and everything is working properly...

pbm@tauri ~ $ cat /etc/env.d/02locale 
LANG="pl_PL.UTF-8"
pbm@tauri ~ $ locale
LANG=pl_PL.UTF-8
LC_CTYPE="pl_PL.UTF-8"
LC_NUMERIC="pl_PL.UTF-8"
LC_TIME="pl_PL.UTF-8"
LC_COLLATE="pl_PL.UTF-8"
LC_MONETARY="pl_PL.UTF-8"
LC_MESSAGES="pl_PL.UTF-8"
LC_PAPER="pl_PL.UTF-8"
LC_NAME="pl_PL.UTF-8"
LC_ADDRESS="pl_PL.UTF-8"
LC_TELEPHONE="pl_PL.UTF-8"
LC_MEASUREMENT="pl_PL.UTF-8"
LC_IDENTIFICATION="pl_PL.UTF-8"
LC_ALL=