CODEWITHSUNDEEP
bash
sergiopereira
sergiopereira

Reputation: 2066

Load environment variables from file just for the next script

I have one of those .env files with several variables set, like:

VAR1=111
VAR2=222

I want to run a script (without changing it) that makes use of those variables. I know I can source that file in the shell and export the variables from the file, like:

set -a
source myenvs.env   # this is my .env file
set +a
./myscript.sh  # this will use the variables

The problem with that is it loads all those variables in my shell, which I don't want (shell pollution.)

What I'm looking for is the equivalent of using env VAR1=111 VAR2=222 ./myscript.sh but getting those variables from the .env file instead.

Upvotes: 1

Views: 74

Answers (2)

oguz ismail
oguz ismail

Reputation: 50775

Do that in a subshell and main shell's environment won't be altered. E.g:

(
  set -a
  source myenvs.env   # this is my .env file
  exec ./myscript.sh  # avoid unnecessary fork()
)

The truth is I need to keep that script flexible to run with different combinations of settings. Imagine I have several .env files like development.env, stagin.env, repro-bug-123.env, etc.

A function would be more useful in that case.

with_env() (
  set -a
  source "$1"
  shift
  exec "$@"
)

with_env myenvs.env ./myscript.sh

Upvotes: 2

Ivan
Ivan

Reputation: 7287

Declare vars that you don't want to change as read only

declare -r VAR3 VAR4

and source the rest

. ./myenvs.env

Upvotes: -1

Related Questions