If you want to make an environment variable visible system-wide, you should set
it in /etc/environment. To set environment variables per user, you have to
modify ~/.pam_environment.
The following is a sample ~/.pam_environment file contents.
JAVA_HOME OVERRIDE=/path/to/java/home
PATH OVERRIDE=${PATH}:${JAVA_HOME}/bin
I’ve always had problems with ~/.pam_environment for it duplicates my entries
in PATH. So, I use the system-wide configuration file, i.e.,
/etc/environment.
References
- https://help.ubuntu.com/community/EnvironmentVariables
man pam_env/etc/security/pam_env.conf