BASH: Is "export" needed, when setting a variable in .bashrc?

Question

I wonder if there is a need to use "export" when setting a variable in .bashrc.

In my tests editing .bashrc there was no difference between

foo=bar

and

export foo=bar

In both cases, after login "echo $foo" outputs "bar".

I am using Debian Squeeze, if that matters.

Thank you guys in advance.

Answer 1

Try creating a shell script that accesses the foo variable.

If foo was export'ed, it will be visible in the shell script, otherwise it won't.

Answer 2

SuperUser has this covered.

Short answer: export makes sure the environment variable is set in child processes. If you don't export, it's only available in the same process/interactive session.