Hi! > > > This patch series introduces TTY keyboard status request, a feature of > > > the n_tty line discipline that reserves a character in struct termios > > > (^T by default) and reacts to it by printing a short informational line > > > to the terminal and sending a Unix signal to the tty's foreground > > > process group. The processes may, in response to the signal, output a > > > textual description of what they're doing. > > > > > > The feature has been present in a similar form at least in > > > Free/Open/NetBSD; it would be nice to have something like this in Linux > > > as well. There is an LKML thread[1] where users have previously > > > expressed the rationale for this. > > > > > > The current implementation does not break existing kernel API in any > > > way, since, fortunately, all the architectures supported by the kernel > > > happen to have at least 1 free byte in the termios control character > > > array. > > > > I like the idea... I was often wondering "how long will this dd take". (And > > in > > case of dd, SIGUSR1 does the job). > > > > I assume this will off by default, so that applications using ^T today will > > not > > get surprise signals? > > If any of isig, icanon and iexten is disabled on the tty, the signal is > not sent.
As expected.
> Any application that wants to handle raw terminal input events itself,
> e.g. vim, mutt, libreadline, anything ncurses-based, etc., has to turn
> off the tty's cooked mode, i.e. at least icanon. This means those
> applications are unaffected.
Agreed, those are unaffected.
But if I have an application doing read() from console (without
manipulating tty), am I going to get surprise signal when user types
^T?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures)
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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