portably printing pointers (was Novice MicroSoft C5.1 question)

[Chris Torek]

In article <171 at srchtec.UUCP> johnb at srchtec.UUCP (John Baldwin) writes:
>[%p] solves a lot of problems for portability, and I for one am very glad
>I was wrong (I've been grumbling all this time about not being able to
>portably print pointers).

Although ANSI says that `%p' prints a pointer (of type `void *') and thus
this is in a sense `portable', it also goes on to say `in an implementation-
defined manner', so in another sense this is not anywhere near portable.
One possible manner for printing a pointer would be to print a mailing
address for one house/apartment/whatever somewhere in the world, with
a different (and unique) address for each possible pointer value.

	printf("%p %p %p", (void *)ptr1, (void *)ptr2, (void *)ptr3);

might produce

	9191 Farrel Avenue
	Columbus, OH

	12500 Lakeshore Drive
	Chicago, IL

	17 Ashburn Pl
	Avenue, MD

(Yes, there is a town in MD called `Avenue'.  I made up the other parts
though.)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
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