Question

I’m trying to modify an existing shell script to accept user input and handle some system exports. The below is an excerpt from a larger script. After running this script, I echo $TEST_DIR and I don’t get anything back. Any ideas?

#!/bin/sh

if [ -z "$TEST_DIR" ]
then
    echo "TEST_DIR was not set, please enter the path: "
    read input_variable
    export TEST_DIR=$input_variable
    exit 1
fi

Answer 1

Save this as script.sh.

#!/bin/bash

if [ -z "$TEST_DIR" ]
then
    echo "TEST_DIR was not set, please enter the path: "
    read input_variable
    export TEST_DIR=$input_variable
fi

And run it like this:

. ./script.sh

Or, equivalently:

source ./script.sh

source runs the script in the current environment and consequently lets you modify the environment in the script. Without it every command, which runs as a child of the shell process, is only given a copy of the current environment.

Note I removed the exit line, as it would terminate the shell in this case.