🚀 go-pugleaf

In article <325@nsta.UUCP>, amos@nsta.UUCP writes:
> One of the optional flags of the c_cflag field of termio is CLOCAL. (see
> <termio.h>)  It is  supposed  to  cause the  tty  driver  to ignore  the
> 'carrier detect' bit  in the RS232 interface, and open  the line anyway.
> 
> However, the  only way to set  this flag is  by a ioctl call;  the ioctl
> call needs  a file-descriptor  argument; a  file-descriptor can  only be
> obtained by a successfull open call...

there is a flag (least ways in system V there is a flag ...)
in fcntl.h named O_NDELAY that causes the open to not wait,
and if i remember the documentation correctly, one of the
uses given is opening a port that doesn't have DSR or DCD
asserted yet.

i have used this approach on our p/60 and p/95, and it works
on them.  as they say, "your mileage may vary ..."

also, i seem to remember that some of the cu(1)'s i've seen
have a no-wait flag (i recall it is used for dialing out on
modems since DCD wouldn't have been asserted yet.  might
want to try that approach.

- john.
-- 
John F. Haugh II		HECI Exploration Co. Inc.
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