Xref: utzoo unix-pc.general:2212 comp.sys.att:5500
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!gatech!rutgers!att!icus!lenny
From: lenny@icus.islp.ny.us (Lenny Tropiano)
Newsgroups: unix-pc.general,comp.sys.att
Subject: Re: termio(7) and read(2) problem!
Message-ID: <599@icus.islp.ny.us>
Date: 10 Feb 89 04:50:14 GMT
References: <137@zebra.UUCP> <7411@chinet.chi.il.us> <10652@stb.UUCP>
Reply-To: lenny@icus.islp.ny.us (Lenny Tropiano)
Distribution: na
Organization: ICUS Software Systems, Islip, New York
Lines: 36

In article <10652@stb.UUCP> michael@stb.UUCP (Michael) writes:
|>In article <7411@chinet.chi.il.us> les@chinet.chi.il.us (Leslie Mikesell) writes:
|>>In article <137@zebra.UUCP> vern@zebra.UUCP (Vernon C. Hoxie) writes:
|>>>
|>>>	I have been trying to write a test program for a Trailblazer.
|>>>It is connected to /dev/tty000.  The program opens this file with:
|>>>
|>>>	fd = open("/dev/tty000", O_RDWR | O_NDELAY);
|>>
|>>You probably need to use fcntl() to turn off the O_NDELAY before
...
|>
|>Does anyone know how to turn ON NDELAY for an already open file?
|>			Michael
...

Use the fcntl(2) system call.

#include <fcntl.h>

int	oflags;

	/* assume a file descriptor (fd) is already open and in use */
	...
	fcntl(fd, F_GETFL, &oflags);	/* get the current open flags */
				/* set the flags to have O_NDELAY too */
	fcntl(fd, F_SETFL, oflags | O_NDELAY);	

I assume that would do it for ya...

-Lenny
-- 
Lenny Tropiano             ICUS Software Systems         [w] +1 (516) 582-5525
lenny@icus.islp.ny.us      Telex; 154232428 ICUS         [h] +1 (516) 968-8576
{talcott,decuac,boulder,hombre,pacbell,sbcs}!icus!lenny  attmail!icus!lenny
        ICUS Software Systems -- PO Box 1; Islip Terrace, NY  11752