Set an environment variable per user shell independent

Question

How can I set an permanent environment variable per user independent from the used shell (bash, zsh and fish)?

not sure I understood, but if you want to set an environment variable for all shells, you can put it in ~/.profile (for one user) or /etc/profile (for all users) — tbrugere, Jun 24 '21 at 14:43
then, you could, in /etc/profile add a source $HOME/.custom-profile, and use that (though it's a bit hacky) — tbrugere, Jun 24 '21 at 14:47
@MarcusMüller bash does read .profile when started as a login shell. The exception is only if you or your sysadmin have created a ~/.bash_profile file. Then, but only then, bash will skip ~/.profile and read that one instead. — terdon, Jun 24 '21 at 14:52
@MarcusMüller see the "INVOCATION" section in man bash, also reproduced in this question: Why are interactive shells on OSX login shells by default? — terdon, Jun 24 '21 at 15:12

tbrugere · Answer 1 · 2021-06-24T16:24:06.343

1

EDIT: according to What's the best distro/shell-agnostic way to set environment variables?, the best solution for this is ~/.pam_environment

EDIT: reverted to the hacky solution since ~/.profile is not read by all shells:

All shells source /etc/profile.

That means in /etc/profile, you could put a line like

. $HOME/.custom-profile

Then, you could add your variables to ~/.custom-profile for each user

edited Jun 24 '21 at 16:24

answered Jun 24 '21 at 14:49

tbrugere

996

You are just recreating the existing functionality. This is what ~/.profile is for. If a shell reads /etc/profile, it will also read ~/.profile. – terdon Jun 24 '21 at 15:09
yep, I was misguided by the comment telling that bash didn't read ~/.profile, editing – tbrugere Jun 24 '21 at 16:10
The zsh shell does not read ~/.profile by default, and neither does the fish shell. – Kusalananda Jun 24 '21 at 16:17
@terdon zsh only reads /etc/profile if it's started in sh or ksh compatibility mode. The fish shell does not to my knowledge read /etc/profile. – Kusalananda Jun 24 '21 at 16:19
ok reverting to previous answer – tbrugere Jun 24 '21 at 16:20
Note that source is a built in utility in some shells. The POSIX equivalent is . (dot). Fish has source too, but it's unclear whether any other command in /etc/profile would understood by that shell. – Kusalananda Jun 24 '21 at 16:23
I changed source to ., though, do you have an example of shell that doesn't understand source? – tbrugere Jun 24 '21 at 16:26
@Kusalananda Seriously? Wow. My apologies, Nephanth, I stand corrected. – terdon Jun 24 '21 at 16:37
@terdon No problem, I was unaware too – tbrugere Jun 24 '21 at 16:39

Marcus Müller · Answer 2 · 2021-06-24T15:20:38.617

All shells read different per-user profile files (zsh: ~/.profile, bash: ~/.bash_profile, csh has only an rc file, and so on). So you'd have to change all of these potential candidates.

However, most shells at the very least fall back to reading ~/.profile (thanks @terdon for pointing this out!), so that's where you can put your exports.

Since "logging in" is usually done by a process having the ability to change its uid and gid (typically: a login manager runnning as root), it's up to these programs to define the environment for the spawned program (e.g. a shell).

But: there's more than one login manager (your GDM/lightdm/KDM/... visual login manager, getty, logind/loginct, ssh, getty...), and they read configuration from different files, so there's no consistent way there, either.

Set an environment variable per user shell independent

2 Answers2