Duboucher Thomas wrote:
> Bean a écrit :
> > Hi,
>
> > This one work:
>
> > int
> > auth_strcmp (const char *s1, const char *s2)
> > {
> >   int result = 0;
>
> >   while (1)
> >     {
> >       result += (*s1 != *s2);
> >       if (*s1 == 0)
> >     break;
>
> >       s1++;
> >       s2++;
> >     }
>
> >   return (result != 0);
> > }
>
> > The trick is to compare the ending '\0' as well, so that partial match
> > is not satisfied.
>
>
>     Yep, I like this one, but I would prefer using an OR instead of an ADD
> (with a highly hypothetical integer overflow :p) and because it's nicer
> in terms of pure logic.
>     "The comparison beetwen s1 and s2 is false if *s1 is different from
> *s2, or recursively if the comparison beetwen s1+1 and s2+1 is false"
>
> int
> auth_strcmp (const char *s1, const char *s2)
> {
>   int ret = 0;
>
>   for (;;)
>   {
>     ret |= (*s1 != *s2);
>
>     if (*s1 == '\0')
>       break;
>
>     s1++;
>     s2++;
>   }
>
>   return ret;
> }
>
But now it has a technical problem: it may read post array definitions.
If any of post-array memory is MMIO or absent reading from it may have
peculiar consequences
>     Also, because s1 and s2 have two differents roles, I think it would be
> best to give them names that better suits them. ;)
>
>     Thomas.

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-- 
Regards
Vladimir 'phcoder' Serbinenko