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From: einari@rhi.hi.is (Einar Indridason)
Newsgroups: comp.lang.c
Subject: 10 commandments and the NULL pointer?
Message-ID: <2390@krafla.rhi.hi.is>
Date: 8 Nov 90 10:20:21 GMT
Organization: University of Iceland
Lines: 40


I just 'troff'-ed Henry Spencer's 10 commandments and read it.  It is great
and it is now hanging in my wall at home.  However one question entered my
mind:  (a question that perhaps should be in the FAQ list, and perhaps is
there?)

The question is about NULL pointers.  Suppose I have the following code:

------------------------------------------------------
#include <whatever_needs_to_be_included.h>

int do_something(int *par1, double *par2, char *par3)
{
	/* do something with those pointers/parameters */
	/* return some value to tell how well we did */
}


main()
{
	.....

	x = do_something(NULL, NULL, NULL);
	/* is            ^^^^  ^^^^  ^^^^  this right or should I write: */

	x = do_something( (int *)NULL, (double *)NULL, (char *)NULL );

	/* which form should I use?  (that is, should I cast the NULL value */
	/* to int pointer, double pointer, char pointer?) */
}
-----------------------------------------


Thanks for your time.

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