How can I export all bash variables declared in a file as environment variables?

Question

Let us say I have a txt file vars.txt like this.

VAR1=32
VAR2=47
VAR3=78

Now if I simply do source vars.txt , these variables won't be exported as environment variables because I didn't prefix them with export .

So, my question is, is there a way to export all those variables without having to prefix them with export in the file?

Answer 1

Yes, there is a way: set -a

From help set

Options:
-a Mark variables which are modified or created for export.

To export every variable in your file you would do

set -a
source yourFile
set +a