Compares not more than maxchar characters of two ASCII character
    strings and returns a negative, 0, or positive integer,
    indicating that the ASCII values of the individual characters
    in the first string are less than, equal to, or greater than the
    values in the second string.

    Format

      #include  <string.h>

      int strncmp  (const char *str_1, const char *str_2, size_t
                   maxchar);