bob@imsvax.UUCP (Bob Burch) (11/05/87)
Short of modifying a port driver (which we lack source code for) and re- building unix, the right way to do it, is there any way to prevent application programs from ever seeing a string begun by a Control-A (hex 1) and ended with a carriage return coming from a port? You would think you could write a filter which looked sort of like: for(;;) { c = getc(); if (c == 1) { while( (c = getc()) != 13); } else putc(c)(); } possibly using reads and writes to dev/tty and possibly using some combination of "stty raw" or "stty raw > /dev/tty" etc. and then piping the application programs with the filter. The filter is easy enough to make work under DOS, but I have tried every combination of things I can think of which is anywhere close to being logical and can't make it work under unix (ULTRIX). The unix daemons and gremlins take over every time, and strange and exotic things happen. The situation arises from a customer's insistance on connecting a computer to a device which appears to be intended only to connect terminals together in a sort of a talk-net and which produces the control-A strings at unpredictable times, often to let a terminal user know that someone other than the one he is talking to is trying to get through (call on hold). Any help would be appreciated. Ted Holden HT Enterprises