If fseek() always clears EOF, is there a way for me to fread() from an
offset of a file and still be able to detect EOF?i.e. withouting using
fseek(). I also need to seek to an offset in the file
frequently(forw ards and backwards) and do fread() from that offset.
Or better still, could anyone let me know some good ways to achieve
what I need to do as above?Can I get hold of the file and being able
to read in without using fread()? Using memory addresses?
Thanks
Mar 24 '07
20  7533 
Mark McIntyre wrote:
On Sun, 25 Mar 2007 22:52:04 -0700, in comp.lang.c , Keith Thompson
<ks***@mib.orgw rote:
>Chris Torek <no****@torek.n etwrites:
>>On very old MS-DOS systems, and systems that predated MS-DOS, *disk*
files had a peculiar problem: they did not have a "size" associated
with them. Instead of a "size", they had a "number of disk sectors".
I assume this kind of behavior is also why an implementation is
allowed to append arbitrarily many null characters to the end of a
binary file.
At least as likely it was due to VMS - all files are multiples of 512
bytes long, padded with nulls as required. Text files had ascii 26 to
mark the 'end' but the OS still considered a 12-byte file to be 512
bytes in size.
BTW isn't the file management family tree VMS->CPM->DOS?
Maybe so. CP/M used IBM's 8-inch floppy format as its basis. The IBM
unit record (sector) was 128 bytes and it was the smallest unit you
could read/write. Text files were terminated with ASCII 26 as above.
--
Joe Wright
"Everything should be made as simple as possible, but not simpler."
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