Losing pending input in entering RAW or CBREAK
Steve Summit
scs at adam.mit.edu
Tue May 7 11:29:22 AEST 1991
In article <243 at bria.UUCP> uunet!bria!mike writes:
>In an article, dfenyes at thesis1.med.uth.tmc.edu (David Fenyes) writes:
>|When I switch from cooked to CBREAK, any pending input appears
>|to be discarded. How can this be avoided or worked around?
>|
>|I'm using Coherent. Is this an anomaly, or standard tty behavior?
>
>An excerpt from The Holiest of Tomes:
>
> TCSETA set the parameters associated with the terminal
> from the structure passed as `arg'. The change
> is immediate
>
> TCSETAF wait for the output to drain and flush the input
> queue before setting the new parameters
>
>It would seem that the ioctl() that is setting the terminal characteristics
>is using TCSETAF which is forcing the flush on the input queue. If
>your cbreak is homegrown, then try using TCSETA instead.
I'm not familiar with Coherent, either, and Michael is probably
correct in assuming that it is termio and/or termios based, but
in case it derives from V7 and/or BSD, the equivalent ioctl's are
TIOCSETP set tty parameters (and flush pending input)
TIOCSETN set tty parameters (no flush of pending input)
Steve Summit
scs at adam.mit.edu
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