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From: patrick@engrhub.ucsb.edu (Patrick Lindstrom)
Newsgroups: comp.os.os2
Subject: Re: Is there a way to peek ahead and see how many bytes are in the COM buffer?
Message-ID: <3425@hub.UUCP>
Date: 28 Dec 89 22:37:51 GMT
References: <1989Dec24.103004.26003@larouch.uucp>
Sender: news@hub.UUCP
Reply-To: patrick@engrhub.UUCP (Patrick A. Linstruth)
Organization: University of California, Santa Barbara
Lines: 17

In article <1989Dec24.103004.26003@larouch.uucp> yozzo@larouch.UUCP (Ralph Yozzo) writes:
>
>Does anyone know of a way to peek ahead and see how many bytes are in 
>the COM1 buffer?
>The reason I ask is that I'd like to read as many bytes
>as possible from the COM port and I'd rather
>not ask for too much because the DosRead() will block.
>

Ralph, I have one more suggestion...  If you don't want the device driver
to block, you can user IOCtl Category 1, Function 53h to set the read
mode to no-wait.  This will tell the device driver to return with as
many characters as are in the receive queue.  If there aren't any
characters it just returns a byte count of 0.

Patrick Linstruth
patrick@wongo