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Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cbmvax!snark!eric
From: eric@snark.uu.net (Eric S. Raymond)
Newsgroups: comp.lang.c,comp.arch,comp.unix.wizards
Subject: A challenge -- C preprocessor expression for machine's `endian-ness'?
Message-ID: <1VZjQh#7Lz9by=eric@snark.uu.net>
Date: 25 Feb 90 16:00:32 GMT
Followup-To: poster
Lines: 17

I'm tuning and adapting Ralph Merkle's snefru code for use as a netnews
authentication tag. It would be immensely useful if I could do the following:

#if (<unknown-expression>)
#define LITTLE_ENDIAN		/* machine words have LSB first */
#else
#define BIG_ENDIAN		/* machine words have MSB first */
#endif

For those of you who don't recall, the expression may use constants of
integral type, sizeof(), unary ops - ~ and !, binary ops + - / * << >> == != <
<= > >= & ^ | && ||, the ternary op ?: and casts. Parentheses for grouping
are permitted. Can anyone come up with such an expression?

Please reply by email. Results will be summarized to comp.lang.c.
-- 
      Eric S. Raymond = eric@snark.uu.net    (mad mastermind of TMN-Netnews)