Fix PWD directory of start script

[Tony763]

Description

Hi, I'm proposing a fix for issue #3137.

For getting directory use $PWD and for getting directory of script which was caller use $0.

How to test

Try to start Mycroft by calling mycroft-start debug and sh start-mycroft.sh debug

Contributor license agreement signed?

CLA [x] (Whether you have signed a CLA - Contributor Licensing Agreement

[forslund]

Hmm, I see that the current code isn't quite working correctly. However the change doesn't seem to work if calling the script from outside the mycroft-core folder (which I believe was the intent of the original code).

[Tony763]

If I call mycroft-start debug from my home folder, it works normally.

Or You think calling start-mycroft.sh? Should it be called directly?

[forslund]

At least it worked previously.

A simple addition seems to be to add

cd $(readlink -f "$0" | xargs dirname)

before the setting DIR (the old version did something similar)

which will execute the script from the mycroft folder.

The mycroft-start duplicates this but in a bash-specific way.

@PureTryOut do you have any suggestions or comments?

[Tony763]

If I change cd -P "$( dirname "$SOURCE" )" into cd $(readlink -f "$0" | xargs dirname) in start-mycroft.sh then it can be called from every place. But If I call mycroft-start then it will point to the wrong directory (/srv/mycroft-core/bin). $0 will return path to first called script.

[PureTryOut]

@PureTryOut do you have any suggestions or comments?

Well my suggestion would be merging #2802 which changes large parts of the script anyway. 😜

The original code wasn't mean to make it possible to run the script from everywhere persé. As far as I can see it will always cd to where the script is located (the real location, not any symlink). I suppose the bin/mycroft-start use-case hasn't been tested very well, but with #2802 I was getting rid of the duplicated entry point anyway.

I'm not entirely sure what to do here besides just getting my PR in, having 2 differently located and named entry points is a bit of a strange situation anyway.