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Comment by kazinator | Hacker News Reader

I'm astonished that the BSD projects are merging un-Unix-like fluff like this.

Meanwhile, the Linux kernel has removed Shift-PgUp scrollback from the console.

What does this mean ? IIRC ^t has been in the BSD for over 20 years, maybe even in early days. ^t just maps to a signal.

I can find SIGINFO all the way back to 4.3BSD-Reno, released in 1990.

Why did they do that? I'm sure there's a good reason but it sounds interesting!

The good reason is apparently that scrollback in vgacon was broken and there was no-one to fix it. No-one has stepped up to volunteer to keep it fixed in the future in the two and a half years since then.

* https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux...

Long-term we'll probably end up with the console in userspace, which should naturally normalize scrollback behavior across all the kms drivers.

There's already kmscon but I haven't looked closely into what prevented that transition from moving forward as the default. Presumably there's a bunch of edge cases a kernel based console doesn't suffer from, like having to avoid oom killer or getting paged out/becoming unresponsive on systems falling over etc.

The console process will have to be something exceptionally configured, pinned memory, realtime priority, oom-immune, all that jazz.

Not really. Most of such a system can just be ordinary processes, and there's no requirement for pinned memory anywhere. Pretty much only the terminal emulator processes are problems if they die, as that effectively becomes a hangup signal, so only they need the oom immunity, if that.

* https://jdebp.uk/Proposals/linux-console-daemon.html

What happened to kmscon is that the systemd people, having adopted it with much hullabaloo, dropped it a while later with far less fanfare.

That said, there are a range of options for people who want to build Linux without CONFIG_VT.

* https://jdebp.uk/Softwares/nosh/user-vt-screenshots.html

* https://jdebp.uk/Softwares/nosh/guide/user-virtual-terminals...

(-:

WAT, how is this "un-Unix-like"?

Unix-like is that the program is dead silent while nothing is going wrong and then indicates its progress by a successful termination status.

It is silent until you press ^t, and then it prints the current progress. It's not constant output.

Sure, but the BSD convention meets that until you hit ^T, and then it does the thing the user wants (give a report) and then it goes back to being silent. There's nothing wrong with that, and the BSDs are Unixen, so... It's not like ^Z (SIGTSTOP) is un-Unix-like just because Unix VII (and System V) didn't have it!

Unix-like sounds unreasonable if there isn’t leeway for optionally reporting progress on stderr (--quiet/--non-quiet or similar).

No news is good news

UNIX-like is having your session or app time out because it gets no output. going all the way back to HP Omniback 2 running BCV split pre-exec scripts on an EMC array to back up a database to tape off a split mirror. Then aborting the backup because the array-side mirror split took over 15min, with no output.

UNIX-like is not a convention of UNIX - it's a convention of "we didn't get to making that useful thing yet, there's other stuff to do."

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