Article View: comp.bugs.sys5
Article #568Re: CLOCAL, or catch-22
From: Philip Peake
Date: Mon, 10 Aug 1987 10:08
Date: Mon, 10 Aug 1987 10:08
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In article <325@nsta.UUCP>, amos@nsta.UUCP (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... Look at your manual, section 2, entry for 'open'. There it tells you all about the flag O_NDELAY that you can use when opening a device. Philip
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!uunet!seismo!mcvax!inria!axis!philip From: philip@axis.fr (Philip Peake) Newsgroups: comp.bugs.sys5 Subject: Re: CLOCAL, or catch-22 Message-ID: <276@axis.fr> Date: Mon, 10-Aug-87 06:08:13 EDT Article-I.D.: axis.276 Posted: Mon Aug 10 06:08:13 1987 Date-Received: Wed, 12-Aug-87 04:45:06 EDT References: <325@nsta.UUCP> Organization: Axis Digital, Paris Lines: 17 Summary: Try NODELAY