Question

I am currently looking for a way to set enviroment variables in Linux via a simple shell script. Within the script I am currently using the ‘export’ command, however this only has scope within the script where system-wide scope is needed.

Is there anyway I can do this via a shell script, or will another method need to be used?

Answer 1

When you run a shell script, it executes in a sub-shell. What you need is to execute it in the context of the current shell, by sourcing it with:

source myshell.sh

or:

. myshell.sh

The latter is my preferred approach since I’m inherently lazy.

If you’re talking about system-wide scope inasmuch as you want to affect everybody, you’ll need to put your commands in a place where they’re sourced at login time (or shell creation time), /etc/profile for example. Where you put your commands depends on the shell being used.

You can find out what scripts get executed by examining the man page for your shell:

man bash

The bash shell, when invoked as a login shell (including as a non-login shell but with the --login parameter), will use /etc/profile and the first of ~/.bash_profile, ~/.bash_login or ~/.profile.

Non-login bash shells will use. unless invoked with --norc or --rcfile <filename>, the files /etc/bash.bashrc and ~/.bashrc.

I’m pretty certain it’s even more convoluted than that depending on how the shell is run, but that’s as far as my memory stretches. The man page should detail it all.