Re: [linux-pm] [PATCH] ACPI: replace strlen("string") withsizeof("string") -1

From: Alan Stern
Date: Mon Aug 06 2012 - 15:59:31 EST


On Mon, 6 Aug 2012, Pavel Vasilyev wrote:

> >> http://www.gossamer-threads.com/lists/engine?do=post_attachment;postatt_id=41157;list=linux
> >
> > Interestingly, many (all?) of the changes in that patch are wrong
> > because they don't try to match the terminating '\0'. As a result,
> > they will match against extensions of the target string as well as the
> > target string itself.
> >
>
> strNcmp compare N bytes - http://lxr.linux.no/#linux+v3.5/lib/string.c#L270
> memcmp compare N bytes - http://lxr.linux.no/#linux+v3.5/lib/string.c#L651

Yes. So if s contains "abcde" then

memcmp(s, "abc", 3) and strncmp(s, "abc", 3) will both return 0, and
memcmp(s, "abc", 4) and strncmp(s, "abc", 4) will both return 1.

Alan Stern

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