The function strcmp compares characters
of the string pointed to by sptr1
to the string pointed to by sptr2,
up to the first terminating null-character in either string.
Arguments
The arguments sptr1 and sptr2 each point to strings,
and each string is an array of characters terminated by a null-character.
Return values
The function strcmp returns an integer value less than,
equal to or greater than zero to indicate whether the string pointed to by
sptr1 is lexicographically less than, equal to or greater than
the null-terminated string pointed to by sptr2.
Usage
The function strcmp uses native character comparison.
The sign of the value returned when one of the characters has its
high-order bit set is implementation-dependent.