Yes, there are certain things in UNIX which _are_ part of the standard (POSIX / IEEE1003) but _aren't_ usually implemented as system calls. Name lookups (wheth

Yes, there are certain things in UNIX which _are_ part of the standard (POSIX / IEEE1003) but _aren't_ usually implemented as system calls. Name lookups (whether user identities or network resources) are the biggest chunk of these. You have a "choice" as a user/programmer here. Say, the existing name lookup interfaces in most libc implementations don't do DNS-over-HTTP (DoH); you can implement that yourself and just use the addresses returned by your library/package where the system calls ... want addresses. If you have the go stance, go all the way. Don't say "the C runtime is sh*te but I really really really want that one particular teensy tiny bit of it could someone somewhere somehow please do something to make it a little less sh*te". Legacy baggage is a burden and backwards compatibility shackles you. The C/Unix interfaces are full of this, and with the hindsight of 50 years noone today, not even "C programmers", would implement them all the same way again. But that doesn't mean their behaviour can be arbitrarily changed.