Running shell script using .env file

Question

I am fairly new to running scripts in UNIX/Linux. I have a .env file containing environment information and a .sh script containing folder creations etc for that environment.

How would I run the script on the environment contained in the .env file or how could I point the script to the target environment?

Would it be as easy as:

bash 'scriptname.sh' 'filename.env'

Solution 1

You need to source the environment in the calling shell before starting the script:

source 'filename.env' && bash 'scriptname.sh'

In order to prevent polution of the environment of the calling shell you might run that in a sub shell:

(source 'filename.env' && bash 'scriptname.sh')

Solution 2

. ./filename.env 
sh scriptname.sh

First command set the env. variables in the shell, second one will use it to execute itself.

Solution 3

Create the a file with name maybe run_with_env.sh with below content

ENV_FILE="$1"
CMD=${@:2}

set -o allexport
source $ENV_FILE
set +o allexport

$CMD

Change the permission to 755

chmod 755 run_with_env.sh

Now run the bash file with below command

./run_with_env.sh filename.env sh scriptname.sh

Comments

[eltiare]

I have my .env file set up as lines of VAR=val. This loaded the variables properly for me.

[phil294]

dont you also need set -a beforehand? Otherwise, the environment variables wont be exported and the script scriptname.sh will not have access to any of those. Why is this upvoted / what am I missing?

[hek2mgl]

@phil294 It depends. From reading the question it seemed to me that env.sh does already use export. If it's only setting variables but does not export them, then set -a might be an option. Well, it would export all variables from the calling script, not just those from env.sh, which might or might not be desired.