I just want to change some behaviours of this script, that's all.
It's obvious you would like to do that :) My suggestion was about studying the current solutions and approaches, which are recommended regarding this script, instead of creating something, which will be not covered by easy updates and may be even insecure. In 15 years each new question like yours coming to this forum, in 95% is repeated. There's not only you trying to modify the software, and you have all rights to do this; my advice, however, is about that you do this properly
to avoid problems and stay out of support.