top, fixed buffer length in utils.c
Michelle Sullivan
michelle at sorbs.net
Sun Feb 1 13:14:31 UTC 2015
Paul Koch wrote:
> On Sun, 1 Feb 2015 17:51:59 +0800
> Erich Dollansky <erichsfreebsdlist at alogt.com> wrote:
>
>
>> Hi,
>>
>> I came across this here in utils.c which is part of top:
>>
>>
>> /*
>> * How do we know that 16 will suffice?
>> * Because the biggest number that we
>> will
>> * ever convert will be 2^32-1, which
>> is 10
>> * digits.
>> */
>>
>> char *itoa(val)
>>
>> register int val;
>>
>> int can be 64 bits on a amd64 machine. Why is the author of this code
>> so sure that we will never cross the 32 bit boundary?
>>
>> Erich
>>
>
> I thought an 'int' was a 32bit number on amd64 arch.
>
IIRC reading at least one of the C 'standards' (don't recall if it was
ANSI or C99) sizeof(int) has to be determined at runtime time because it
could be 8, or 16 bit and that wasn't dependent on the arch type, it was
dependent on the compiler (and maybe other factors.) Unfortunately when
I queried this with a Uni Prof as to why, I was told, mostly its 16 bits
but you should always check if you have something that cares (where it
matters.)
--
Michelle Sullivan
http://www.mhix.org/
More information about the freebsd-stable
mailing list