linux-kernel - Re: double exclamation (!!) suckage in the kernel

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Message-ID: <20070525202854.GA24801@flint.arm.linux.org.uk>
Date:	Fri, 25 May 2007 21:28:54 +0100
From:	Russell King <rmk+lkml@....linux.org.uk>
To:	Satyam Sharma <satyam.sharma@...il.com>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: double exclamation (!!) suckage in the kernel

On Sat, May 26, 2007 at 01:53:59AM +0530, Satyam Sharma wrote:
> Are all these occurrences merely the debris of
> s/something/!notsomething/g kind of patches or is there some
> dark, unknown C / gcc wizardry I have absolutely no clue of?

Try building and running this:

#include <stdio.h>
int main()
{
	int i;
	for (i = 0; i < 10; i++)
		printf("%d: %d\n", i, !!i);
	return 0;
}

and you should see it's effect.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:
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