1) I hope there will still be the original
w(1)/last(1)/lastb(1)/lastlog(1)/faillog(1)
tools which can still read *old* format utmp/wtmp/lastlog in Debian at
least for
a while after switch to Y2038-safe replacements. Those tools can read
I can only speak for w. It currently prefers what it gets from systemd or elogind, effectively
iterating over the sessions coming from sd_get_sessions() if sd_booted() returns true.
If sd_booted() returns false, then it uses the old utmp/utmpx files for now. Besides the Y2038
issue, the utmp "API" is pretty awful with things like errors pretty much undetectable. There is also
the problem about who (e.g. which process) should be writing to those files as you have pointed out
in your email.
For now w/uptime will use utmp as a fallback, but I'll be happy if this gets updated to something better; it's a low-priority
for me because systemd/elogind do what I need most of the time.
- Craig