Is there a utility to read environment variables from an env file and then run a command (more lightweight than foreman)?

Question

foreman can read .env files and set environment variables from the contents, and then run a program

e.g. 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?

FOO=bar
BAZ=qux

Can you post an example .env file? I suspect `bash .env` or `sh .env` may work? — Daniel Widrick, Sep 20 '13 at 01:28

score 22 · Accepted Answer · answered Sep 20 '13 at 13:40

22

You can source the environment file in the active shell and run the program:

sh -ac ' . ./.env; /usr/local/bin/someprogram'

The -a switch exports all variables, so that they are available to the program.

answered Sep 20 '13 at 13:40

Marco

3

`bash -ac 'source .env && ./program'` – fiatjaf Jan 02 '19 at 14:13
1

@fiatjaf Why would you use bash in this case if the POSIX shell does the job and you need no feature that actually requires bash? Furthermore, bash is not available by default on all systems (e.g. FreeBSD). – Marco Jan 02 '19 at 19:46
1

Oh, right, makes sense, I think your way is better, then. I was just providing the Bash alternative because I felt more comfortable writing it. – fiatjaf Jan 03 '19 at 21:03

score 2 · Answer 2 · answered Jun 19 '14 at 10:39

2

Another alternative is envdir:

envdir runs another program with environment modified according to files in a specified directory.

answered Jun 19 '14 at 10:39

wodow

This post mentions some complementary features between `envdir`, `runit`, and `chpst`; namely ability to have changed env vars reflect in the state of the process being run. The post is about docker but it's not limited to docker. https://blog.ghaering.de/post/docker-as-vm/ [ archive.org: https://web.archive.org/web/20190321165332/https://blog.ghaering.de/post/docker-as-vm/ ] – floer_m Mar 21 '19 at 16:53

score 2 · Answer 3 · answered Oct 07 '17 at 12:39

2

I tried source .env and it worked like a charm. Unfortunately, none of the other solutions posted here worked for me.

answered Oct 07 '17 at 12:39

Shouvik

This works only for valid bash (strings like `export KEY=VALUE`, not `KEY=VALUE`) – LennyLip Jul 27 '21 at 04:01

score 1 · Answer 4 · answered Sep 20 '13 at 13:28

1

This works:

env $(cat .env | tr "\\n" " ") myprogram

but obviously doesn't check the format of the .env file for correctness, which a utility program would do.

answered Sep 20 '13 at 13:28

wodow

1

1) The `cat` is not necessary, just write `tr "\\n" " " < .env` 2) This breaks if multi-line assignments are used. – Marco Sep 20 '13 at 13:44

4 Answers4