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Subject: Re: [PATCH] Re: sscanf("-1", "%d", &i) fails, returns 0
From: Ray Lee <ray-lk@madrabbit.org>
To: hps@intermeta.de, rddunlap@osdl.org
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
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> > What should it do?
> I would model this after user space. (Which does strange things: 

<snip>

It only sounds strange at first. It actually means that scanf is
consistent with C's rules of assignment between mixed types. For
example:

ray:~$ cat signs.c

#include <stdio.h>

main() {
	char scan[]="-100";
	unsigned int u;
	int i;

	sscanf(scan, "%ud", &u);
	sscanf(scan, "%d", &i);
	printf("%s scanned to signed %d and unsigned %u\n", scan, i, u);

	i=-100;
	u=i;
	printf("%d assigned to unsigned int gives %u\n", i, u);
}

ray:~$ ./signs
-100 scanned to signed -100 and unsigned 4294967196
-100 assigned to unsigned int gives 4294967196

So, one should think of scanf as having correct knowledge of the types
it's scanning, and then shoe-horning the result into whatever you asked
for. Just like C itself.

Ray

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