svn commit: r317909 - head/usr.bin/resizewin

[Jilles Tjoelker]

On Sun, May 07, 2017 at 09:01:43PM +0300, Konstantin Belousov wrote:
> On Sun, May 07, 2017 at 05:21:23PM +0000, Edward Tomasz Napierala wrote:
> > Author: trasz
> > Date: Sun May  7 17:21:22 2017
> > New Revision: 317909
> > URL: https://svnweb.freebsd.org/changeset/base/317909

> > Log:
> >   Make resizewin(1) discard the terminal queues, to lower the chance
> >   for "unable to parse response" error which happens when youre typing
> >   too fast for the machine you're running it on.

> >   Reviewed by:	cem, Daniel O'Connor <darius at dons.net.au>
> >   MFC after:	2 weeks
> >   Sponsored by:	DARPA, AFRL
> >   Differential Revision:	https://reviews.freebsd.org/D10624

> > Modified:
> >   head/usr.bin/resizewin/resizewin.c
> > 
> > Modified: head/usr.bin/resizewin/resizewin.c
> > ==============================================================================
> > --- head/usr.bin/resizewin/resizewin.c	Sun May  7 14:59:45 2017	(r317908)
> > +++ head/usr.bin/resizewin/resizewin.c	Sun May  7 17:21:22 2017	(r317909)
> > @@ -52,7 +52,7 @@ main(__unused int argc, __unused char **
> >  {
> >  	struct termios old, new;
> >  	struct winsize w;
> > -	int ret, fd, cnt, error;
> > +	int ret, fd, cnt, error, what;
> >  	char data[20];
> >  	struct timeval then, now;
> >  
> > @@ -71,6 +71,12 @@ main(__unused int argc, __unused char **
> >  	if (tcsetattr(fd, TCSANOW, &new) == -1)
> >  		exit(1);
> >  
> > +	/* Discard input received so far */
> > +	what = FREAD | FWRITE;
> > +	error = ioctl(fd, TIOCFLUSH, &what);
> This is correctly spelled tcflush(fd, TCIOFLUSH);

Alternatively, the above TCSANOW could be changed to TCSAFLUSH. The
effect is slightly different in that pending output is drained instead
of discarded.

In any case, the TIOCFLUSH ioctl is non-standard and should not be used
directly.

-- 
Jilles Tjoelker