[csl]

If you often wonder about such things, I highly recommend the book "Advanced programming in the UNIX environment" by Stevens/Rago: https://en.m.wikipedia.org/wiki/Advanced_Programming_in_the_...

It covers a lot of stuff in an authoritative way. For example, how one should implement a daemon properly (e.g., chdir to root to allow for unmounting the disk the program originally ran from, lots of stuff like that). I'll actually doubly recommend it, because it's so good.

[Nullabillity]

Of course, a lot of the daemon boilerplate no longer really applies in the modern systemd world.

[JdeBP]

It didn't in fact apply to a sizeable portion of the pre-systemd world, either. systemd doco gives the quite false impression that this stuff is new, for "new-style daemons". Not using this boilerplate has been the right way to write daemons for many systems over the past quarter century, going back to the release of the IBM System Resource Controller at the beginning of the 1990s.