export doesn't work in shell script but does via CLI

Question

I have the following file - test.sh - in .:

#!/bin/sh
export ASDF=test

I do chmod +x test.sh,then ./test.sh and finally echo $ASDF and... nothing. It's as though $ASDF hasn't been set. But if I do it via the CLI instead of a shell script it works just fine and $ASDF is defined.

Why isn't the shell script working?

Answer 1

It is because:

./test.sh

will create a sub shell and set env variables in the sub shell. Once sub shell exits this variable isn't available in parent shell.

Use this form to avoid forking a sub shell and execute test.sh in the current shell itself:

. ./test.sh

OR:

source ./test.sh

Now that variable ASDF will be available in current shell also.