X-Authentication-Warning: delorie.com: mailnull set sender to djgpp-bounces using -f
Date: Wed, 05 Dec 2001 19:37:28 +0200
From: "Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
Sender: halo1 AT zahav DOT net DOT il
To: roland_asmann AT yahoo DOT com
Message-Id: <7263-Wed05Dec2001193728+0200-eliz@is.elta.co.il>
X-Mailer: emacs 21.1.50 (via feedmail 8 I) and Blat ver 1.8.9
CC: djgpp AT delorie DOT com
In-reply-to: <20011205153352.33164.qmail@web9103.mail.yahoo.com> (message from
	ROLAND on Wed, 5 Dec 2001 07:33:52 -0800 (PST))
Subject: Re: Serial Communicaton
References:  <20011205153352 DOT 33164 DOT qmail AT web9103 DOT mail DOT yahoo DOT com>
Reply-To: djgpp AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: djgpp AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com
Precedence: bulk

> Date: Wed, 5 Dec 2001 07:33:52 -0800 (PST)
> From: ROLAND <roland_asmann AT yahoo DOT com>
> > 
> > For working examples of using Filesystem Extensions
> > for similar
> > purposes, look in ports of GNU software, such as GNU
> > Fileutils (file
> > ls-msdos.c) and Ispell (file djterm.c).
> 
> Where are these Filesystem Extensions for?

They are part of the DJGPP library, and are documented in the library
reference manual.  From the shell prompt, type this:

   info libc alpha "File System"

and read there.

> And why do I need them?

You need them because DOS doesn't allow you to do with communication
ports what Unix does.  For example, on Unix one can call the functions
`ioctl' to send commands to the communications device driver, e.g. to
change the baudrate.  This cannot be done on DOS.  So you need a means
to catch the library calls which use a specific file handle (the one
you open to the communication port) and redirect those calls to the
functions from the async communication library.  That's what
Filesystem Extensions allows you to do.

> Well I am having trouble with a struct sgttyb... I
> replaced this by a struct termios, but then I get
> errors about some members of the struct that do not
> exist...

You could define your own struct sgttyb, or steal the definition from
the nearest Unix box.

> And furthermore my program tells me it doesn't know
> TIOCNXCL...

That's because its definition in sys/ioctl.h is commented out (as all
that functionality isn't supported).  You could copy that part of
ioctl.h into your program, and use it.