var args

Henry Spencer henry at utzoo.UUCP
Sun Oct 16 14:15:33 AEST 1983


How do you implement variable numbers of arguments in C?  In a word,
unportably.  (Is that a word?)  The implementation is fundamentally
machine-dependent.  There are portable "library" facilities for doing
it in some Unixes, but the insides of those libraries are still quite
machine-dependent.  Scanning a variable-length argument list requires
knowing the C calling sequence on the machine in question, so that you
know how the arguments are laid out in core.  Machines differ enough
on this point that machine-independent code for it is impossible.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry



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