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From: jfh@rpp386.cactus.org (John F Haugh II)
Newsgroups: comp.unix.internals
Subject: Re: Serial I/O
Message-ID: <18801@rpp386.cactus.org>
Date: 11 Dec 90 00:46:32 GMT
References: <1990Nov26.092137.5629@oilean.uucp> <1629@svin02.info.win.tue.nl>
Reply-To: jfh@rpp386.cactus.org (John F Haugh II)
Organization: Lone Star Cafe and BBS Service
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In article <1629@svin02.info.win.tue.nl> debra@svin02.info.win.tue.nl (Paul de Bra) writes:
>In article <1990Nov26.092137.5629@oilean.uucp> joe@oilean.uucp (Joe McGuckin) writes:
>>I have an application that needs to send/receive stuff from a serial port in
>>an async. manner. I know that Unix's tip forks a seperate processes for sending
>>and receiving chars...
>
>Look at the source for kermit (public domain).
>As far as i know it does everything with only one process.

Ah, but Kermit cheats.  It sends packets and then receives packets - it is 
very much a synchonous protocol.  For async transfers you need something
more clever.

The "real" answer is the use select(), poll() or some combination of
vmin=0/vtime=0 termio magic.  Issue a select() call for all of your fd's
and let the system figure it out ...
-- 
John F. Haugh II                             UUCP: ...!cs.utexas.edu!rpp386!jfh
Ma Bell: (512) 832-8832                           Domain: jfh@rpp386.cactus.org