@b0rk It seems mostly disused these days, but Ctrl-O...

@b0rk It seems mostly disused these days, but Ctrl-O used to be bound to DISCARD by default. When typed by the user, the terminal driver would discard (“flush”) all output to the terminal until the program next read from the terminal.

This was useful if some command produced a lot of unwanted output, especially on a slow terminal. I first saw this on TOPS-20, and it also appeared in BSD Unix.

Like 30 October at 2:05 | Wall-to-wall | Open on mastodon.social

3 comments

Stuart Marks

@b0rk Another obscure character is Ctrl-Y (DSUSP, delayed suspend). Similar function to Ctrl-Z, which sends SIGTSTP immediately. However, Ctrl-Y is buffered up by the terminal driver with other input. When it is about to be read by the program, the driver sends SIGTSTP at that point and discards the Ctrl-Y.

I think both DSUSP and DISCARD are BSDisms. Various man pages seem to indicate they aren’t supported on Linux.

30 October at 2:10 | Open on mastodon.social

Adrian Cockcroft

@stuartmarks @b0rk I remember using Ctrl-O on vt220 terminals to shut them up. Not sure if it was a thing on paper roll tty-33 and Dec-10 because that was too long ago…

30 October at 3:23 | Open on mastodon.social

Dmitri Kalintsev

@stuartmarks @b0rk omg where were you in 86 when I was trying to get stuff done using the godawful slow-ass terminals on our uni's PDP11?

30 October at 6:08 | Open on infosec.exchange

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