在zsh上运行bash脚本不会获取环境变量

Question

I have the following bash script. It is actually an env variable file that contains some environment variables I want to set depending on an argument I pass in when I source it. Here is a MWE.

#!/usr/bin/env bash

# CONSTANTS
PROD_STR='prod'
TEST_STR='test'

# Set the environment: 'prod' or 'test'
if [ "$1" == $PROD_STR ] || [ "$1" == $TEST_STR ]; then
    export DEV_ENV=$1
    echo "Found valid dev environment: "$DEV_ENV
else
    echo "No valid environment specified"
    echo "Usage: env_vars <env>"
    echo '       env - one of "prod" or "test"'
fi  

case $DEV_ENV in
    $PROD_STR)
        export MY_HOST='fooProd.net'
        export PORT='8000';;
    $TEST_STR)
        export MY_HOST='fooTest.net'
        export PORT='8100';;
esac

export API_USERNAME='foo'
export API_PASSWORD='mypwrd'

Now I wanted to source this file which I have named test_env_var.sh . I tried.

1. source test_env_var.sh prod It gives me the following test_env_var.sh:8: = not found

2. . ./test_env_var.sh prod . ./test_env_var.sh prod . It still gives me: ./test_env_var:8: = not found .

3. ./test_env_var prod It now runs without errors and echoes (as it should) the output Found valid dev environment: prod .

So now after doing (3) I would expect to see my env variables set. But when I do

echo $API_USERNAME

It doesn't return anything.

Workaround

I temporarily change my $SHELL into bash by typing bash on the prompt. Then I run the script as

. test_env_var prod

and now when I try to echo any env variable I have set (for example echo $API_USERNAME it returns me foo as it should ). Even if I change back to zsh by typing zsh the environment variables are still there.

Question: Why is this happening?. Is there no way for me to run this bash script without changing the $SHELL to bash?. Perhaps the syntax of the bash script needs to change so that it runs on zsh . But that's not an option since this file is under version control.

Some more context Both my zsh and bash are usr/local/bin/ so the shebang #!/usr/bin/env bash should take care of this, I would think.

Answer 1

Change

if [ "$1" == $PROD_STR ] || [ "$1" == $TEST_STR ]; then

to

if [ "$1" = $PROD_STR ] || [ "$1" = $TEST_STR ]; then

== is a bash extension. = is the standard POSIX syntax, which is supported by both bash and zsh .