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From: SRFERGU@ERENJ.BITNET (Scott Ferguson)
Newsgroups: comp.sys.apollo
Subject: ms_$mapl and fseek/fread
Message-ID: <8910232135.AA06237@umix.cc.umich.edu>
Date: 23 Oct 89 20:35:07 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
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I am using ms_$mapl to create a giant file (a collation of 300-800 image
files, each approximately 512x320 in size, two bytes per pixel) for later
tomographic inversion (CT-scan stuff).

Now, like a smartass, I want to read the file using standard fseek and fread
calls. I want to do this because we have an Ardent on the network which does
blinding FFT's and has NFS.

When I do fseek, I get "no problem" back from the OS, but fread returns a
value of 0 bytes read. Then, I call perror to get the file error, and it
gives me a zero error also. SO, there's no error condition, but I didn't
get any bytes. Is what I'm trying feasible, or do I have to create the file
with stdio calls in order to read it back?

Thanks in advance,
Scott Ferguson
ferguson@erenj.bitnet
Exxon Research & Engineering
Annandale, NJ 08801
(201) 730-2339