don't understand a command "."

Shell Programming and Scripting
1

Hi all,

I have a script with those two lines :

test -f $PWD/mysetup.txt
. $PWD/mysetup.txt

I understand the first one, but could anyone explain me the role of the second one? All the thing I find is the usage :

Thx in advance

2

IT sources a file - meaning it runs the shell script IN THE CURRENT process - this is the way you can run a script to set/change environment variables.

Ordinary runs of a script are in a child process. No changes to environment variables are passed from the child back up to the parent.

3

It is called sourcing. It will kind of include or import the things that are in that text-file. If it was a definition of variables or some commands executing, these would be sourced into the calling script too.

Here is a thread about it

4

Ok, tanks for your answers both of you!