add macOS support, and refactor

Added daemon support for MacOS. Used launchd and launchctl, which are analogous to linux's systems and systemctl.

launchd: https://www.manpagez.com/man/5/launchd.plist/, https://www.launchd.info/

launchctl: https://ss64.com/osx/launchctl.html

Also refactored the file.