environment_variables
2522
Comment: Documented ugly problem with $LANG being defined in 2 places
|
2551
Added doc category
|
Deletions are marked like this. | Additions are marked like this. |
Line 60: | Line 60: |
---- CategoryDocumentation |
Global Environment Variables
These may be put in one of these files:
- /etc/environment (try this file first)
- /etc/profile
For example, to set a variable called JAVA_HOME and append it to PATH:
for /etc/environment:
JAVA_HOME="/usr/lib/j2sdk1.5-sun" (A colon followed by no directory is treated as the current working directory) PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/bin/X11:/usr/games:$JAVA_HOME:"
for /etc/profile:
export JAVA_HOME="/usr/lib/j2sdk1.5-sun" export PATH="$PATH:$JAVA_HOME:"
Locale Environment variables
Some programs rely on the value of $LANG, which defaults to en_US.UTF-8. (For example, Thunderbird changes the displayed date format based on this). The variable is set in both /etc/enviroment and in /etc/default/locale. To make a system-wide change that is certain to take effect, both of these must be modified; it's also necessary to log out and back in again.
Session Specific Environment Variables
You may sometimes want variables defined locally (eg: restricted to your accounts shell only) and not globally (all users). So just append whatever variables you need defined to your ~/.bashrc file.
If instead you want a temporary variable created only for your current shell session, then do this inside the shell:
export SOMEDIRECTORY="/some/location" export SOMEVALUE="500"
Bash Shell Environment Variables
Some of what is mentioned below may be specific to Ubuntu only.
- when starting a shell after you've logged in already, either from the console or thru X display manager, that shell will be an interactive non-login shell, which will read /etc/bash.bashrc and ~/.bashrc.
- when the user starts a bash shell by logging into a console or via SSH, this starts a login shell, which will read /etc/environment, /etc/profile, /etc/bash.bashrc, ~/.bash_profile, ~/.bash_login, and ~/.profile.
- If Bash is invoked with the name sh, whether as an interactive login shell, or as a non-interactive shell with the '--login' option, it first attempts to read and execute commands from '/etc/profile' and '~/.profile', in that order.
Display contents of $PATH
Just `echo $PATH'
References
[http://www.gnu.org/software/bash/manual/bashref.html Bash Reference]
[http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=2&chap=5 Environment Variables @Gentoo Wiki]
See Also
environment_variables (last edited 2008-08-06 17:01:23 by localhost)