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From: edw@ius2.cs.cmu.EDU
Newsgroups: comp.lang.c
Subject: Re: Byte vs. Word Alignment - (nf)
Message-ID: <7022@brl-adm.ARPA>
Date: Tue, 21-Apr-87 11:21:28 EST
Article-I.D.: brl-adm.7022
Posted: Tue Apr 21 11:21:28 1987
Date-Received: Wed, 22-Apr-87 03:21:29 EST
Sender: news@brl-adm.ARPA
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In article <6700007@iaoobelix.UUCP>, wagner@iaoobelix.UUCP writes:
>
>     struct foo {
>         char frob_1;
>         int frob_2;
>     };
>
> I intended to send something like the above structure as a packet over the
> net. You know what happened? The VAX/uVAX produces *8* as sizeof struct foo,
> whereas the Sun program yields *6*. The client program, run on the VAX sent
> a packet of size 8, and the daemon on the Sun thought the packet size was 6.

  Comment aside from byte alignment. If the Vax has to interpret that
structure (ie needs to use frob_2) , you may find it a problem since byte
ordering of integers differ on Vaxen and Suns.  I suggest you look at the
eXternal Data Representation (XDR) section of the sun networking manual.
You may find it a problem to use those since as far as I know, neither Berkley
nor Sys V support these networking primatives sign :-(. But suppositely
Mach will take care of this by supporting its own version of XDR :-).
Well I shall find out.

--
                    Eddie Wyatt

They say there are strangers, who threaten us
In our immigrants and infidels
They say there is strangeness, too dangerous
In our theatres and bookstore shelves
Those who know what's best for us-
Must rise and save us from ourselves

Quick to judge ... Quick to anger ... Slow to understand...
Ignorance and prejudice and fear [all] Walk hand in hand.
                    - RUSH