Sudhanshu Mishra - Setting up environment variables on Mac

Basics

Mac OSX is based on BSD. Most terminal commands work similar with a few variations.

Environment variables

Setting up permanent variables

NOTE I've found that irrespective of how the variables are set, the terminal session needs to be quit and relaunched for the SET or UNSET to reflect. In case of applications that need to read the variables, you need to quit and relaunch the application.

Manual way: open up /Users/username/.bash_profile and add a line like so (create the .bash_profile file if it does not already exist at the location specified above):

export MYVARIABLE=value

The .bash_profile is a shell script that is executed when a terminal session starts.

Alternative Described here. Especially useful if you need GUI applications launched via spotlight (Launched via CMD+Space shortcut) to be able to use environment variables.

launchctl setenv MYVARIABLE "value"

OR create a file launchd.conf : /etc/launchctl.conf and place a line as shown below:

# will set an environment variable named JAVA_VERSION globally for all users
setenv JAVA_VERSION 1.6

Script

#!/usr/bin/env bash

# Stackoverflow: 
# MYVARIABLE+x is shell expansion
if [ -z ${MYVARIABLE+x} ] 
then
    echo "MYVARIABLE is unset, setting it now";
    echo 'export MYVARIABLE=whatevervalue' >>~/.bash_profile
else 
    echo "MYVARIABLE is set to '$MYVARIABLE'"; 
fi

NOTE the current shell session needs to be restarted for changes to take effect. This can be done by closing and reopening the terminal or by typing source ~/.bash_profile

Hope that helps!