I was looking for the difference between the "." and "source" builtin commands and a few sources (e.g., in this discussion, and the bash manpage) suggest that these are just the same.

However, following a problem with environment variables, I conducted a test. I created a file testenv.sh that contains:

#!/bin/bash
echo $MY_VAR

In the command prompt, I performed the following:

> chmod +x testenv.sh
> MY_VAR=12345
> ./testenv.sh

> source testenv.sh
12345
> MY_VAR=12345 ./testenv.sh
12345

[note that the 1st form returned an empty string]

So, this little experiment suggests that there is a difference after all, where for the "source" command, the child environment inherits all the variables from the parent one, where for the "." it does not.

Am I missing something, or is this is an undocumented/deprecated feature of bash?

[ GNU bash, version 4.1.5(1)-release (x86_64-pc-linux-gnu) ]