When setting up environment variables, for example in .profile you can write the following near the top of the file to enable exporting of all the environment variables without explicitly writing “export” each time:

set -o allexport

with the above, then you can just write the following, for example:

TEST_DIR=/tmp/test

instead of

export TEST_DIR=/tmp/test

To disable the all export:

set +o allexport

You are also able to set environment variables without the export or allexport, however that will NOT make the variable available to sub-processes.