BTW: another old V6 trick is the use file redirection from the different terminal to unlock a hosed tty. Programming on the console was fraught with multiple dragons and not recommended. But due to program crashes that left things in raw mode, I admit that I remember having to uses the redirection trick a few times to get the console back. As Noel said, it could get dicey if the console ended up with canonicalization turned off. V7's ½ cooked (*a.k.a.* CBREAK) was a welcomed edition, but the fact is V6's try handler was good enough most needs and a lot of used it pretty successfully for a long time. Clem On Sat, Jul 25, 2020 at 12:02 AM John Cowan wrote: > Ctrl+J actually is the keystroke for U+000D LINE FEED, so it always works; > old-timers got in the habit of typing ^Jreset^J. > > Note that if a program gets stuck in rare mode rather than raw mode, you > can get out of it with ^C (or whatever INTR is set to), a good reason for > using rare mode. > > > On Fri, Jul 24, 2020 at 10:49 PM Paul Riley wrote: > >> Yep already fallen into that trap. Glad I'm running on a sim! Yes I'd >> considered writing a small program to reset the STTY settings, and you've >> helped me to understand how I can run it! >> >> In answer to the CR question, is it that in raw mode, the CR does not get >> mapped to LF, and therefore the shell doesn't see the LF character and >> recognize the end of the line? Incidentally, why the ^J before ft? Just to >> clean up the shell input status? >> >> I'll write my own ft, thanks. I'll try raw mode, because I want some >> better line editing capability. >> >> Alternatively if I toy around with /dev/tty does that interfere with the >> operation of the standard console outside of my app? >> >> Paul >> >> *Paul Riley* >> >> >> >> >> On Fri, 24 Jul 2020 at 22:36, Clem Cole wrote: >> >>> >>> >>> On Thu, Jul 23, 2020 at 10:29 PM Noel Chiappa >>> wrote: >>> >>>> ... >>>> This is not a C issue; it's the Unix I/O system (and specifically, >>>> terminal I/O). >>> >>> >>>> ... >>> >>> One can suppress all this; there's a mode call 'raw' >>>> >>> Just be sure to turn raw mode off so canonization is performed again >>> after your program stops running. Remember this a 'system wide' >>> settings for that try and all programs start to use that setting. So if >>> some reason, your program stops and a new program (like the shell) takes >>> back over input from the try, if you do not have a way to get it back you >>> are screwed. >>> >>> Back in the day, I have a shell script in my path stored in ~/.bin >>> called: ft (fix tty) which called the stty command with the way I >>> wanted the terminal to be set up. Thus is I was running a program >>> that core dumped and left the try in raw mode, if I could find a way to run >>> the ft script (usually by typing ^Jft^J ) life was good again. Paul, >>> as an exercise why would ft not be good enough? (hint read and >>> study the section 4 man page for stty) >>> >>> FWIW: is how the original UCB ex/vi and Cornell's Fred editors for v6 >>> works by the way. I suspect that iyou look at any of the video editors of >>> the day it will show you the details. >>> >>> One of the differences between V7 and earlier UNIX tty handlers was that >>> they tty canonization was split into multiple parts. Also the other hint >>> with Sixthedition's version of raw and cooked modes, you get all or nothing so >>> you if you turn on raw, your program, will have do things like backspace >>> processing, *etc*.. >>> >>>