Even with Ryan's generous posting limits here on this node, there wasn't room to expand on what "wildly adventurous" encompassed, but it definitely encompassed having the right magtape kit.
So of course DECTape. (-: People like this ran their Unices on DEC kit.
Random old Usenet example:
https://groups.google.com/g/comp.os.vms/c/R6BtGeKB640/m/-RuOQO0WICgJ
There's an earlier reference in that thread to someone having both filesystem and swap on tape having been reported on in the BSTJ.
And I've been reminded, the subject of #rwhod having come up earlier this week, that there was once an rtar command for accessing other people's magtape devices over the Internet.
Usefully, there's a comp.sources.unix index in what I'm backing up with #pax, so I looked it up. It says that rtar was in volume 2 in 1985.
… the obvious I-am-using-rsync-anyway solution becomes a small /run/uptime file or some such.
#rwhod very quickly disappears from the system with only a small evolution, as by this point one has bypassed most of its function and made it into a pretty much just a tool for making a mangled copy of utx.active and a couple of sysctl results.
I wouldn't be so sure.
Once one gets to the point that one is just externally syncing #rwhod's files, it's not a great leap to realize that one might as well cut out the middle-man entirely: rsync (or whatever) the original utx.active files themselves, rather than have rwhod read them and chop off the fields at 8 characters, and just turn rwho into something that effectively runs who against a bunch of filenames.
ruptime is slightly trickier, but …
#rwhod was deprecated by the #FreeBSD people in 2017. Five days later they were un-deprecated, drawing a distinction between rlogin/rsh and rwho/ruptime. At least one person was relying upon the latter.
https://reviews.freebsd.org/D11743
#rwhod is in #FreeBSD, #NetBSD, #Debian, #Arch, and probably others. With subtle differences as they have diverged from the Berkeley root.
https://packages.debian.org/source/stable/netkit-rwho
https://aur.archlinux.org/packages/netkit-rwho-debian
Amusingly, the Arch people have given it a systemd unit, but haven't given it a systemd socket unit or done any of the fork-removal work to let systemd handle the privileges.
And because their unit file/rc script doesn't specify the option, it still runs as the superuser on both Debian and Arch.
This is what happens when I finally get so exasperated at my machine slowing down in the wee small hours that I comb through /etc/periodic to see what it is actually doing and find rwho in there. Twice.
P.S.: By Friday, please.
(-:
Interesting final note:
#FreeBSD/#NetBSD (and netkit-rwho) #rwhod uses the original "who" UDP port, 513.
There's a "new-who" UDP+TCP port, 550 and a "new" 224.0.2.1 multicast address. They have been in the assigned number list ever since RFC 1090, footnoted to Jon Postel and the "unofficial" BSD "rwho Group".
They've been reserved for 35 years, and I can find nothing to show for the efforts of whatever this "unofficial Group" was.
10. IPv6 exists.
11. fstatat() exists. You don't have to hardwire the private database location so you can get back there from chdir("/dev"). But anyway ...
12. You might not need a login database or /dev. The kernel has all of the info about current sessions, their terminals, and their setlogin() names, in memory, but just lacks a sysctl for reading it out.
Tool changes:
5. Follow UCSPI-UDP and UCSPI-TCP conventions, at minimum as an option. Let someone else with privileges open the socket.
6. Don't fork-and-exit. Allow simple logging to standard error. Let someone else have already dropped privileges and chdir()ed you. Permit proper process supervision.
7. --help
8. Allow the login database to be configurable, as a command line option or some such.
9. Permit a reduced mode where multiple terminals are squashed into one.
JdeBP
JdeBP