Newsgroups: comp.lang.c
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Absolute size of 'short'
Message-ID: <1988Aug2.234117.26042@utzoo.uucp>
Organization: U of Toronto Zoology
References: <214@ISIDAPS5.UUCP>
Date: Tue, 2 Aug 88 23:41:17 GMT

In article <214@ISIDAPS5.UUCP> mike@ISIDAPS5.UUCP (Mike Maloney) writes:
>Is the size of a (signed or unsigned) short integer guarenteed to
>be two bytes?

No.

>I need to manipulate and compare some unsigned ints
>modulo 65536.  It would be clean and convenient to just let the
>machine handle my wrap-around from 0 to 0xffff and verse-vica.

For unsigned numbers this would work, *if* you can find an unsigned size
that is two bytes long.  There are no guarantees at all about that.  (For
example, I believe there's a C compiler for the pdp10, and shorts would
pretty well have to be either 18 or 36 bits there.  What they are on a
64-bit machine like a Cray, I have no idea, but I wouldn't count on them
being 16.)

I think the most portable way is to use (perhaps unsigned) long and do an
"&0xffff" at strategic places.
-- 
MSDOS is not dead, it just     |     Henry Spencer at U of Toronto Zoology
smells that way.               | uunet!mnetor!utzoo!henry henry@zoo.toronto.edu