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/*

FUNCTION

        <<wcpncpy>>---copy part of a wide-character string returning a pointer to its end

ANSI_SYNOPSIS

        #include <wchar.h>

        wchar_t *wcpncpy(wchar_t *<[s1]>, const wchar_t *<[s2]>, size_t <[n]>);

TRAD_SYNOPSIS

        wchar_t *wcpncpy(<[s1]>, <[s2]>, <[n]>

        wchar_t *<[s1]>;

        const wchar_t *<[s2]>;

        size_t <[n]>;

DESCRIPTION

        The <<wcpncpy>> function copies not more than n wide-character codes

        (wide-character codes that follow a null wide-character code are not

        copied) from the array pointed to by <[s2]> to the array pointed to

        by <[s1]>. If copying takes place between objects that overlap, the

        behaviour is undefined.

        If the array pointed to by <[s2]> is a wide-character string that is

        shorter than <[n]> wide-character codes, null wide-character codes are

        appended to the copy in the array pointed to by <[s1]>, until <[n]>

        wide-character codes in all are written.

RETURNS

        The <<wcpncpy>> function returns <[s1]>; no return value is reserved to

        indicate an error.

PORTABILITY

<<wcpncpy>> is ISO/IEC 9899/AMD1:1995 (ISO C).

No supporting OS subroutines are required.

*/

#include <_ansi.h>

#include <wchar.h>

wchar_t *

_DEFUN (wcpncpy, (dst, src, count),

        wchar_t * dst _AND

        _CONST wchar_t * src _AND

        size_t count)

{

  wchar_t *ret = NULL;

  while (count > 0)

    {

      --count;

      if ((*dst++ = *src++) == L'\0')

        {

          ret = dst - 1;

          break;

        }

    }

  while (count-- > 0)

    *dst++ = L'\0';

  return ret ? ret : dst;

}