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don't understand a command "."

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# 1  
Old 08-05-2009
don't understand a command "."
Hi all,

I have a script with those two lines :
Code:
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 :
Quote:
.: usage: . filename [argument]

Thx in advance
# 2  
Old 08-05-2009
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  
Old 08-05-2009
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
https://www.unix.com/shell-programmin...ion-shell.html
# 4  
Old 08-05-2009
Ok, tanks for your answers both of you!
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