export environment varible from bash script with argument - bash

Question

I am trying to export environment variable using a bash script which takes one argument. I tried to run the script using source command, but it does not work.
source ./script.sh dev
My example script below
#!/bin/bash
# Check 1 argument is passed with the script
if [ $# -ne 1 ]
then
echo "Usage : $0 AWS account: e.g. $0 dev"
exit 0
fi
# convert the input to uppercase
aws_env=$( tr '[:lower:]' '[:upper:]' <<<"$1" )
if ! [[ "$aws_env" =~ ^(DEV|UAT|TRN|PROD)$ ]]; then
# check that correct account is provided
echo "Enter correct AWS account: dev or uat or trn or prod"
exit 0
else
# export environment variables
file="/home/xyz/.aws/key_${aws_env}"
IFS=$'\n' read -d '' -r -a lines < $file
export AWS_ACCESS_KEY_ID=${lines[0]}
export AWS_SECRET_ACCESS_KEY=${lines[1]}
export AWS_DEFAULT_REGION=ap-southeast-2
echo "AWS access keys and secret has been exported as environment variables for $aws_env account"
fi
Content of file /home/xyz/.aws/key_DEV. Its a sample only, not real keys.
$ cat key_DEV
123
xyz
When I say it does not work, nothing happens in the terminal, it closes the terminal when I run the script.
Further update:
When I run the script as is from the terminal without source (./script.sh dev) it seems to be working fine, with the debug (set -x), I can see all the outputs are correct.
However, the issue is when I run with source (source ./script.sh dev), then it fails (closes the terminal, now I know why, because of exit 0), and from the output captured from the debug command I can see that its not capturing $1 argument correctly. The error message "Enter correct AWS account: dev or uat or trn or prod". And, the value of $aws_env variable is blank.
I don't know why the two behaviors are different and how to fix it.
Final update:
The script seems to be fine. The issue was local to my computer. tr was defined as an alias in .bashrc file which was causing the problem. I just used typeset -u aws_env="$1" instead of aws_env=$( tr '[:lower:]' '[:upper:]' <<<"$1" ). Thank you all for helping me to get this one resolved, specifically #markp-fuso.

Answer 1

Try using mapfile instead of read like so...
#!/usr/bin/env bash
# Check 1 argument is passed with the script
if [ $# -ne 1 ]
then
echo "Usage : $0 AWS account: e.g. $0 dev"
exit 0
fi
# convert the input to uppercase
aws_env=$( tr '[:lower:]' '[:upper:]' <<<"$1" )
if ! [[ "$aws_env" =~ ^(DEV|UAT|TRN|PROD)$ ]]; then
# check that correct account is provided
echo "Enter correct AWS account: dev or uat or trn or prod"
exit 0
else
# export environment variables
file="/home/xyz/.aws/key_${aws_env}"
# IFS=$'\n' read -d '' -r -a lines < $file
mapfile -t lines < "$file"
export AWS_ACCESS_KEY_ID=${lines[0]}
export AWS_SECRET_ACCESS_KEY=${lines[1]}
export AWS_DEFAULT_REGION=ap-southeast-2
echo "AWS access keys and secret has been exported as environment variables for $aws_env account"
fi
Make sure you also put quotation marks around "$file"
Another little tip, Bash supports making variables uppercase directly, like so:
var="upper"
echo "${var^^}"