foreman can read .env files and set environment variables from the contents, and then run a program
foreman run -e vars.env myprogram
...but it does a lot of other things (and is primarily concerned with starting things using its Procfile format).
Is there a simpler (Linux/Unix) tool that's just focussed on reading .env files and executing a command with the new environment?
Example environment file (from http://ddollar.github.io/foreman/#ENVIRONMENT ):