### 6.18 `wcsncmp`—compare part of two wide-character strings

Synopsis

         #include <wchar.h>
         int wcsncmp(const wchar_t *s1, const wchar_t *s2, size_t n);

Description
The `wcsncmp` function compares not more than n wide-character codes (wide-character codes that follow a null wide-character code are not compared) from the array pointed to by s1 to the array pointed to by s2.

The sign of a non-zero return value is determined by the sign of the difference between the values of the first pair of wide-character codes that differ in the objects being compared.

Returns
Upon successful completion, `wcsncmp` returns an integer greater than, equal to or less than 0, if the possibly null-terminated array pointed to by s1 is greater than, equal to or less than the possibly null-terminated array pointed to by s2 respectively.

Portability
`wcsncmp` is ISO/IEC 9899/AMD1:1995 (ISO C).

No supporting OS subroutines are required.