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From: ts@cup.portal.com (Tim W Smith)
Newsgroups: comp.lang.c
Subject: compiler detecting divide by zero
Message-ID: <36233@cup.portal.com>
Date: 26 Nov 90 10:46:48 GMT
Organization: The Portal System (TM)
Lines: 44

For obscure reasons that I won't go into, I wanted a divide
by zero in a program.  I was compiling on SCO Unix System V/386
relase 2.2 (I think...) with whatever C compiler comes with
this version of Unix.

I tried the obvious:

	int	i, j;

	i = 1;
	j = 0;
	i/=j;

The compiler caught this.  Grrr.  Next I tried:

	i = 1;
	j = 1;
	i -= 1;
	j/=i;

It still caught it.  Double grrr!

Next try:

	int	i, j, *p;

	i = 1;
	j = 1;
	p = &i;
	j /= *p - 1;

It still caught it!

This one got past it:

	j = 5;
	for ( i = 0; i < 5; i++ )
		j--;
	i /= j;

After the previous try, I was a bit surprised that it didn't
figure out this one!

						Tim Smith