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- - dot space dot (https://www.linuxquestions.org/questions/linux-newbie-8/dot-space-dot-483359/)

can someone tell me why do i have to specfic . ./setup.sh (notice the space) ?

wat does the "space" in between the dots mean?

Thanks.

The first '.' is the command 'source' to read and execute commands from the filename given as argument.
The second '.' is the current directory.
. ./setup.sh
is the same as
source ./setup.sh
or
source setup.sh (if the ./, the current directory, is in the PATH environnement variable).

lol, i still dont get it, cant we just enter ./setup.sh ? in wat kind of circumstance we need to enter 2 dots?

Thanks.

With the 'source' or '.' command the script need not be executable.
If you use ./setup.sh the file must be so (eg 'rwxr-xr-x' permissions).

alright , i got it.

thanks.

But more importantly:
- If you use the "source" or "." keywork, the script is executed in the current environment, which means that changes to variables (eg: PATH) or other (eg: cd /some/directory/) are still valid.
- Else such changes are forgotten when execution is done.

Example:

Code:

(/home/yves)$ echo $PATH

/bin:/usr/bin:/usr/X11R6/bin

(/home/yves)$ cat test.sh

export PATH=/usr/local/bin:$PATH

cd /usr/local

echo $PATH

pwd

(/home/yves)$ ./test.sh

/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin

/usr/local

(/home/yves)$ echo $PATH

/bin:/usr/bin:/usr/X11R6/bin

(/home/yves)$ . ./test.sh

/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin

/usr/local

(/usr/local)$ echo $PATH

/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin

Notice how things remain changed when the script is sourced.

Yves.