#include <cstring>
  int strncmp( const char *str1, const char *str2, size_t count );

The strncmp() function compares at most count characters of str1 and str2. The return value is as follows:

Return value Explanation
less than 0 ''str1'' is less than ''str2''
equal to 0 ''str1'' is equal to ''str2''
greater than 0 ''str1'' is greater than str2''

If there are less than count characters in either string, then the comparison will stop after the first null termination is encountered.