User:Aimilius/Environment variables

Using pam_env

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The PAM module pam_env(8) loads the variables to be set in the environment from the following files: /etc/security/pam_env.conf, /etc/environment and ~/.pam_environment.

/etc/environment must consist of simple VARIABLE=value pairs on separate lines, for example:
```
EDITOR=NANO
```

/etc/security/pam_env.conf and ~/.pam_environment share the same following format:
```
VARIABLE [DEFAULT=value] [OVERRIDE=value]
```
@{HOME} and @{SHELL} are special variables that expand to what is defined in /etc/passwd. The following example illustrates how to expand the HOME environment variable into another variable:
```
XDG_CONFIG_HOME   DEFAULT=@{HOME}/.config
```
Note: The variables ${HOME} and ${SHELL} are not linked to the HOME and SHELL environment variables, they are not set by default.
The format also allows to expand already defined variables in the values of other variables using ${VARIABLE} , like this:
```
GNUPGHOME        DEFAULT=${XDG_CONFIG_HOME}/gnupg
```
VARIABLE=value pairs are also allowed, but variable expansion is not supported in those pairs. See pam_env.conf(5) for more information.

Note: These files are read before other files, in particular before ~/.profile, ~/.bash_profile and ~/.zshenv.