Peter Steinmeyer

Ok, I have found the 'cd ~/' does change the current dir and obviously the $0 parameter which is './installer.sh' is not valid anymore.
I used 'ME=which "$0" to make the path absolute before the cd command is executed.

This looks nice, but unfortunately this is not working for me (trying this on openSUSE 15.2).
grep and tail fail with './insttaller.sh: file not found'
I guess the script is not readable while it is executed.