🚀 go-pugleaf

In article <325@nsta.UUCP> amos%nsta@nsc.com (Amos Shapir) 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.
 > This is needed for  ports that do not have the DC  wired; trying to open
 > such a port without setting the CLOCAL bit first, will cause the open to
 > hang forever waiting for a carrier signal.
 > 
 > 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...
 > 
 > The  only solution  if you  don't have  sources is  to re-wire  all your
 > terminal plugs by shorting CD to DTR or something like that.

In fact what you do is to open the tty line with O_NDELAY set.

	e.g.
	open ("/dev/ttya", O_RDWR | O_NDELAY);

-Nigel
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Nigel Horne, Divisional Director, Root Technical Systems.
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