Newsgroups: comp.os.msdos.djgpp
From: news AT hermes DOT hrz DOT uni-bielefeld DOT de (News Administrator)
Subject: The size of structures and binary files
Message-ID: <33A1B030.309E@post.psychologie.uni-bielefeld.de>
Date: Fri, 13 Jun 1997 20:40:16 GMT
Reply-To: mheumann AT post DOT psychologie DOT uni-bielefeld DOT de
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Dear DJGPP users!

Recently I came across something weird:
I have two structs:
struct s1 { char c1; char c2; short s};
struct s2 { char c1; short s; char c2};

A call to sizeof will return 4 for s1 and 6 (!) for s2.
It seems like the size of the chars in s2 gets increased to 2.

Now I wouldn't care much, if it weren't for writing and reading these
structs to binary files.
A file containing s1 will have 4 bytes, while a file with s2 will have
six.
I have to access binary files, which were created with a program someone
else wrote (and compiled), and it seems like his program would count
4 bytes for both sizes.
The binary files are rather huge and contain several big structs.

Does anybody know of a compiler option or some other way to get DJGPP
to use 1 byte chars regardless of their context?

You could really do me a great favour!

Manni Heumann
Bielefeld, Germany