On Sun, 23 Dec 2018 12:13:43 +0900 Namhyung Kim <[email protected]> wrote:
> > Also, I believe there are some memcmp implementations that start at the > > end of the memory locations, not the beginning. That is, it compares > > backwards. Which is also legit for memcmp to do. > > I'm not sure, the man page says: > > RETURN VALUE > The memcmp() function returns an integer less than, equal to, > or greater than zero if the first n bytes of s1 is found, > respectively, to be less than, to match, or be greater than > the first n bytes of s2. > > For a nonzero return value, the sign is determined by the sign > of the difference between the first pair of bytes (interpreted > as unsigned char) that differ in s1 and s2. > > If n is zero, the return value is zero. > > > It should return difference in the first pair of bytes that differ so > I guess implementations should compare from the beginning. Ah, makes sense. I think I'm thinking of memcpy() which can start at the end, or maybe even the deprecated bcmp(). It's been a long time since I had to deal with the implementations of these. -- Steve
