Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!udel!new
From: new@udel.EDU (Darren New)
Newsgroups: comp.arch
Subject: Re: Endian wars
Message-ID: <8475@louie.udel.EDU>
Date: 10 Feb 89 14:59:12 GMT
References: <6133@columbia.edu> <186@aucsv.UUCP> <21557@ames.arc.nasa.gov> <9468@cit-vax.Caltech.Edu> <21609@ames.arc.nasa.gov>
Sender: usenet@udel.EDU
Reply-To: new@udel.EDU (Darren New)
Organization: University of Delaware
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In article <21609@ames.arc.nasa.gov> lamaster@ames.arc.nasa.gov (Hugh LaMaster) writes:
>In article <9468@cit-vax.Caltech.Edu> wen-king@cit-vax.UUCP (Wen-King Su) writes:
>>In article <21557@ames.arc.nasa.gov> lamaster@ames.arc.nasa.gov (Hugh LaMaster) writes:
>>The SUN's XDR library has already provided us with a common interchange
>>file format.  It probably does not address 64 bit integers.
>
>I remember seeing a definition of XDR a couple of years ago - but in the 
>context of RPC.  Is there an XDR FILE format definition?  NFS certainly
>doesn't translate to/from it. 
>
If you are really looking for a COMMON interchange format, ASN.1 is the way to
go. XDR is nice when you are working with C, but defining something like a font
in a way that is machine independent requires much extra information in terms
of order of bits in a byte and so on. XDR is also not self-delimiting, does
not handle time or alternate character sets well (last I looked), and cannot
be parsed without knowledge of the XDR functions used to encode the higher-level
constructs. ASN.1, having been standardized by ISO (I can find the number if
anyone wants it), is available world-wide. ASN.1 also addresses integers, strings,
etc as big as you want. Unfortunately, it does not at this time have a single,
standard floating-point format, but this is easy to add on an application
basis. This topic seems to be wanderring from comp.arch somewhat...
                      - Darren