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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: <3423@hub.UUCP>
Date: 28 Dec 89 22:32:04 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: 15

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,
There is a Generic IOCtl call that will return to you the size of the
receive buffer and the number of characters currently queued.  I don't
have my device driver technical reference manual handy so I can't tell
you the exact number.  Look for Category 1 function calls in your
device drivers manual.