Setting environment variable in shell script does not make it visible to the shell

unix export environment-variables
GDICommander picture GDICommander · Dec 22, 2011 · Viewed 32.3k times · Source

I want to use a shell script that I can call to set some environment variables. However, after the execution of the script, I don't see the environment variable using "printenv" in bash.

Here is my script:

#!/bin/bash

echo "Hello!"
export MYVAR=boubou
echo "After setting MYVAR!"

When I do "./test.sh", I see:

Hello!
After setting MYVAR!

When I do "printenv MYVAR", I see nothing.

Can you tell me what I'm doing wrong?

Answer

NPE picture NPE · Dec 22, 2011

This is how environment variables work. Every process has a copy of the environment. Any changes that the process makes to its copy propagate to the process's children. They do not, however, propagate to the process's parent.

One way to get around this is by using the source command:

source ./test.sh

or 

. ./test.sh

(the two forms are synonymous).

When you do this, instead of running the script in a sub-shell, bash will execute each command in the script as if it were typed at the prompt.

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