guy@rlgvax.UUCP (Guy Harris) (02/19/84)
The bug in System III no-delay reads from a terminal is that the system always claims that there are no characters available to read. The fix is to change the lines in "ttread" in "io/tty.c": if (tq->c_cc == 0) if (u.u_fmode&FNDELAY) return; else canon(tp); to: if (tq->c_cc == 0) if (u.u_fmode&FNDELAY && tp->t_rawq.c_cc == 0) return; else canon(tp); Thanks and a tip of the Hatlo to Warren Montgomery of BTL UNIX EMACS fame, who discovered this while trying to get EMACS' "look ahead and cancel redrawing" code to work on System III. Guy Harris {seismo,ihnp4,allegra}!rlgvax!guy