wcsncpy, wcsncpy_s

Parameters

Return value

Notes

In typical usage, count is the number of elements in the destination array.

Although truncation to fit the destination buffer is a security risk and therefore a runtime constraints violation for wcsncpy_s , it is possible to get the truncating behavior by specifying count equal to the size of the destination array minus one: it will copy the first count wide characters and append the null wide terminator as always: wcsncpy_s ( dst, sizeof dst / sizeof * dst, src, ( sizeof dst / sizeof * dst ) - 1 ) ;

Example

#include <stdio.h>
#include <wchar.h>
#include <locale.h>
 
int main(void)
{
    const wchar_t src[] = L"わゐ";
    wchar_t dest[6] = {L'あ', L'い', L'う', L'え', L'お'};
 
    wcsncpy(dest, src, 4); // this will copy わゐ and repeat L'\0' two times
 
    puts("The contents of dest are: ");
    setlocale(LC_ALL, "en_US.utf8");
 
    const long dest_size = sizeof dest / sizeof *dest;
    for(wchar_t* p = dest; p-dest != dest_size; ++p) {
        *p ? printf("%lc ", *p)
           : printf("\\0 ");
    }
}

The contents of dest are: 
わ ゐ \0 \0 お \0

References

See also