>>>If the backend file is /dev/lp1 the error is returned. If the backend file
>>>is /dev/tty0 a BREAK signal is transmitted.
>>
(A bunch of stuff about "what a break signal is" and confussion over serial and parallel deleted)
Gee Brad, you just get back from vacation? :) I posted this back in July. I guess I should have posted a followup with the answer received from Rich Coe via mail.
He suggested:
/* push the posix line discipline */
ioctl(fd, TXADDCD, "posix");
ioctl(fd, TCSBRK, 0);
/* pop the posix line discipline */
ioctl(fd, TXDELCD, "posix");
>>>Any ideas?
>
> When using a serial printer, you are normally talking to the serial printer
> line discipline...not the posix line discipline. The TCSBRK and TCSBREAK
> support are in the posix line discipline. You're outta luck.
>
I tried the above and it works fine; it allows sending a break signal over a
serial line defined as /dev/lp1. Hope this helps anyone else trying to print