Why doesn't my environment variable get set?

Question

I have to set an environment variable called GDK_NATIVE_WINDOWS to fix the problem with Eclipse buttons in Ubuntu. To set the environment variable, I added the following line to ~/.pam_environment.

GDK_NATIVE_WINDOWS DEFAULT=true

Surprisingly, the environment variable doesn't get set when I echo $GDK_NATIVE_WINDOWS in a terminal. However, all other environment variables that I've listed in ~/.pam_environment are set properly. Besides, when I switch to a tty, e.g. Alt+Ctrl+F1, the environment variable gets set correctly. Can anyone tell what's wrong with setting this environment variable in ~/.pam_environment?

Answer 1

You have a space in between GDK_NATIVE_WINDOWS and DEFAULT=true . This differs from the example you linked.

Try:

GDK_NATIVE_WINDOWS=true

Answer 2

I think that's because when you start a terminal you are not launching a login session. it's a terminal session, and it works with different rules. I never really got the difference and the need to differentiate, but in any case I suggest you to use ~/.bash_profile and/or ~/.bashrc to achieve the same result, unless you have been suggested to use pam for specific reasons.

Answer 3

As you have identified, your environment variables should be set in ~/.pam_environment as recommended on https://help.ubuntu.com/community/EnvironmentVariables. Easier said than done ;)

It is possible that you ran into the same configuration gap that existed for me. See the workaround for encrypted home below.

My ~/.pam_environment:

PATH            DEFAULT=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:${HOME}/bin
IDEA_JDK        DEFAULT=${HOME}/Applications/jdk

Why the ugly static path? ${PATH} would not work for me. I bricked my login several times trying to work around it so I am sticking with the ugly static copy of the defaults :)

Workaround for Encrypted Home Folders

In Ubuntu releases up to and including Precise 12.04 Beta 2, if you are using an encrypted home directory you will need to modify /etc/pam.d/common-session to get it to load ~/.pam_environment. This solution apparently works for earlier releases, but I have not tested it.

Guenther Montag (g-montag) wrote on 2010-08-19:

This seems to be an issue with encrypted home directories. I added

session required pam_env.so

at the end of /etc/pam.d/common-session and now ~/.pam_environment gets read. On another system without encrypted home directories (also 10.04) the work around is not needed. Perhaps in my case the system tries to read ~/.pam_environment before it is decrypted.

Answer 4

It looks like it's just a bug that my environment variable is not being set.

Answer 5

Stick to the simple "key=value" syntax in the ~/.pam_environment file. No DEFAULT, OVERRIDE, ${HOME}, no nothing. Just key=value. The man page you linked to is for pam_env.conf, only. See "man 8 pam_env" which does not promise anything else "This module can also parse a file with simple KEY=VAL pairs on separate lines.".

By the way putting something like PATH=${PATH}:more/paths in ./pam_environment is a great way to break almost any attempt to login, since the PATH gets set to ${PATH}:more/paths literally (not much to be found there). To rescue, "/bin/mv .pam_environment out_of_the_way" and re-login.