Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!mimsy!umd5!virginia!boole!slb From: slb@boole.acc.virginia.edu (sandy) Newsgroups: comp.bugs.sys5 Subject: Re: CLOCAL, or catch-22 Message-ID: <225@boole.acc.virginia.edu> Date: Fri, 7-Aug-87 11:25:26 EDT Article-I.D.: boole.225 Posted: Fri Aug 7 11:25:26 1987 Date-Received: Sun, 9-Aug-87 08:39:44 EDT References: <325@nsta.UUCP> Reply-To: slb@boole.UUCP (PUT YOUR NAME HERE) Distribution: world Organization: University of Va., Charlottesville, VA Lines: 20 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 .) 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. You can open the line with the O_NDELAY flag set meaning return without waiting for carrier (for a communications line anyway) and then issue the ioctl to set CLOCAL. sandy -- sandy bryant slb@virginia.edu uunet!virginia!slb