Compares the contents of two storage areas specified.
long memcmp (const void *s1, const void *s2, size_t n);
s1 Pointer to the reference storage area to be compared
s2 Pointer to the storage area to compare to the reference
n Number of characters to compare
If storage area pointed by s1 > storage area pointed by s2: Positive value
If storage area pointed by s1 == storage area pointed by s2: 0
If storage area pointed by s1 < storage area pointed by s2: Negative value
The memcmp function compares the contents of the first n characters in the storage areas pointed by s1 and s2. The rules of comparison are implementation-defined.