Path: utzoo!attcan!uunet!lll-winken!ames!haven!purdue!decwrl!decvax!ima!cfisun!lakart!dg
From: dg@lakart.UUCP (David Goodenough)
Newsgroups: comp.lang.c
Subject: Re: What is wrong?
Message-ID: <401@lakart.UUCP>
Date: 25 Jan 89 21:44:10 GMT
References: <2051@ndsuvax.UUCP>
Distribution: na
Organization: Lakart Corporation, Newton, MA
Lines: 21

From article <2051@ndsuvax.UUCP>, by numork@ndsuvax.UUCP (James Mork):
>   I am using TC 1.5 everything was going OK... Now... when I run
>   a simple program like this, the file gets truncated after 25 or
>   26 bytes...    After 25 when I read the file back in, I just
>   get EOF (-1).  What is wrong?  Is this just some error that
>   I am staring at, or is my compiler in foo bar land?

The infamous MS-DOS (and CP/M) end of file problem. 26 is the magic number.
Early DOS programs and ALL CP/M programs that deal with text files do so in
complete blocks: 128 bytes at a time. So how do you deal with a text file
20 characters long? Easy: put the 20 characters in, and fill the rest of
the block with 0x1a. This means that anyone reading the file _IN TEXT MODE_
will see the first 0x1a as an end of file. In particular your putc(26, fp);
will put an EOF in a text file. NOW try doing the same with the files open
in binary mode (r+ or rb or whatever it is), and you may have somewhat
better luck.
-- 
	dg@lakart.UUCP - David Goodenough		+---+
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