Re: line BRK detection on ttyS0

Alan Cox
2010-09-22T23:40:39Z

On Wed, 22 Sep 2010 15:36:48 -0400
Mark Hounschell <markh@compro.net> wrote:

> Does the kernel support sending a SIGINT from a line BRK on ttyS0 to a thread of a process
> where the process has a controlling terminal that is NOT ttyS0 and the thread is using ttyS0
> in a cfmakeraw mode? I see doc that implies that ttyS0 must be the controlling terminal but
> can my thread have a controlling terminal while my main process has it's own ?

If they have two different ttys open then yes at least as far as Linux is
concerned. I don't know how glibc handles it as it can do signal groups
and the like and delivery of signals to process not threads etc.

You can see parity anyway. In PARMRK mode you get \377 \0 [whatever] for
parity/break etc but \377 is also doubled for a real one - ie \377 \377

Alan