WideCharToMultiByte

// KERNEL32.dll
#include <windows.h>

INT WideCharToMultiByte(
    DWORD CodePage,
    DWORD dwFlags,
    LPCWSTR lpWideCharStr,
    INT cchWideChar,
    LPSTR lpMultiByteStr,   // optional
    INT cbMultiByte,
    LPCSTR lpDefaultChar,   // optional
    BOOL* lpUsedDefaultChar   // optional
);

<DllImport("KERNEL32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function WideCharToMultiByte(
    CodePage As UInteger,   ' DWORD
    dwFlags As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPWStr)> lpWideCharStr As String,   ' LPCWSTR
    cchWideChar As Integer,   ' INT
    <MarshalAs(UnmanagedType.LPStr)> lpMultiByteStr As System.Text.StringBuilder,   ' LPSTR optional, out
    cbMultiByte As Integer,   ' INT
    <MarshalAs(UnmanagedType.LPStr)> lpDefaultChar As String,   ' LPCSTR optional
    lpUsedDefaultChar As IntPtr   ' BOOL* optional, out
) As Integer
End Function

' CodePage : DWORD
' dwFlags : DWORD
' lpWideCharStr : LPCWSTR
' cchWideChar : INT
' lpMultiByteStr : LPSTR optional, out
' cbMultiByte : INT
' lpDefaultChar : LPCSTR optional
' lpUsedDefaultChar : BOOL* optional, out
Declare PtrSafe Function WideCharToMultiByte Lib "kernel32" ( _
    ByVal CodePage As Long, _
    ByVal dwFlags As Long, _
    ByVal lpWideCharStr As LongPtr, _
    ByVal cchWideChar As Long, _
    ByVal lpMultiByteStr As String, _
    ByVal cbMultiByte As Long, _
    ByVal lpDefaultChar As String, _
    ByVal lpUsedDefaultChar As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

WideCharToMultiByte = ctypes.windll.kernel32.WideCharToMultiByte
WideCharToMultiByte.restype = ctypes.c_int
WideCharToMultiByte.argtypes = [
    wintypes.DWORD,  # CodePage : DWORD
    wintypes.DWORD,  # dwFlags : DWORD
    wintypes.LPCWSTR,  # lpWideCharStr : LPCWSTR
    ctypes.c_int,  # cchWideChar : INT
    wintypes.LPSTR,  # lpMultiByteStr : LPSTR optional, out
    ctypes.c_int,  # cbMultiByte : INT
    wintypes.LPCSTR,  # lpDefaultChar : LPCSTR optional
    ctypes.c_void_p,  # lpUsedDefaultChar : BOOL* optional, out
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
WideCharToMultiByte = Fiddle::Function.new(
  lib['WideCharToMultiByte'],
  [
    -Fiddle::TYPE_INT,  # CodePage : DWORD
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_VOIDP,  # lpWideCharStr : LPCWSTR
    Fiddle::TYPE_INT,  # cchWideChar : INT
    Fiddle::TYPE_VOIDP,  # lpMultiByteStr : LPSTR optional, out
    Fiddle::TYPE_INT,  # cbMultiByte : INT
    Fiddle::TYPE_VOIDP,  # lpDefaultChar : LPCSTR optional
    Fiddle::TYPE_VOIDP,  # lpUsedDefaultChar : BOOL* optional, out
  ],
  Fiddle::TYPE_INT)

#[link(name = "kernel32")]
extern "system" {
    fn WideCharToMultiByte(
        CodePage: u32,  // DWORD
        dwFlags: u32,  // DWORD
        lpWideCharStr: *const u16,  // LPCWSTR
        cchWideChar: i32,  // INT
        lpMultiByteStr: *mut u8,  // LPSTR optional, out
        cbMultiByte: i32,  // INT
        lpDefaultChar: *const u8,  // LPCSTR optional
        lpUsedDefaultChar: *mut i32  // BOOL* optional, out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("KERNEL32.dll", SetLastError = true)]
public static extern int WideCharToMultiByte(uint CodePage, uint dwFlags, [MarshalAs(UnmanagedType.LPWStr)] string lpWideCharStr, int cchWideChar, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder lpMultiByteStr, int cbMultiByte, [MarshalAs(UnmanagedType.LPStr)] string lpDefaultChar, IntPtr lpUsedDefaultChar);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_WideCharToMultiByte' -Namespace Win32 -PassThru
# $api::WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar)

#uselib "KERNEL32.dll"
#func global WideCharToMultiByte "WideCharToMultiByte" sptr, sptr, sptr, sptr, sptr, sptr, sptr, sptr
; WideCharToMultiByte CodePage, dwFlags, lpWideCharStr, cchWideChar, varptr(lpMultiByteStr), cbMultiByte, lpDefaultChar, varptr(lpUsedDefaultChar)   ; 戻り値は stat
; CodePage : DWORD -> "sptr"
; dwFlags : DWORD -> "sptr"
; lpWideCharStr : LPCWSTR -> "sptr"
; cchWideChar : INT -> "sptr"
; lpMultiByteStr : LPSTR optional, out -> "sptr"
; cbMultiByte : INT -> "sptr"
; lpDefaultChar : LPCSTR optional -> "sptr"
; lpUsedDefaultChar : BOOL* optional, out -> "sptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	procWideCharToMultiByte = kernel32.NewProc("WideCharToMultiByte")
)

// CodePage (DWORD), dwFlags (DWORD), lpWideCharStr (LPCWSTR), cchWideChar (INT), lpMultiByteStr (LPSTR optional, out), cbMultiByte (INT), lpDefaultChar (LPCSTR optional), lpUsedDefaultChar (BOOL* optional, out)
r1, _, err := procWideCharToMultiByte.Call(
	uintptr(CodePage),
	uintptr(dwFlags),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpWideCharStr))),
	uintptr(cchWideChar),
	uintptr(lpMultiByteStr),
	uintptr(cbMultiByte),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(lpDefaultChar))),
	uintptr(lpUsedDefaultChar),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function WideCharToMultiByte(
  CodePage: DWORD;   // DWORD
  dwFlags: DWORD;   // DWORD
  lpWideCharStr: PWideChar;   // LPCWSTR
  cchWideChar: Integer;   // INT
  lpMultiByteStr: PAnsiChar;   // LPSTR optional, out
  cbMultiByte: Integer;   // INT
  lpDefaultChar: PAnsiChar;   // LPCSTR optional
  lpUsedDefaultChar: Pointer   // BOOL* optional, out
): Integer; stdcall;
  external 'KERNEL32.dll' name 'WideCharToMultiByte';

result := DllCall("KERNEL32\WideCharToMultiByte"
    , "UInt", CodePage   ; DWORD
    , "UInt", dwFlags   ; DWORD
    , "WStr", lpWideCharStr   ; LPCWSTR
    , "Int", cchWideChar   ; INT
    , "Ptr", lpMultiByteStr   ; LPSTR optional, out
    , "Int", cbMultiByte   ; INT
    , "AStr", lpDefaultChar   ; LPCSTR optional
    , "Ptr", lpUsedDefaultChar   ; BOOL* optional, out
    , "Int")   ; return: INT

●WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar) = DLL("KERNEL32.dll", "int WideCharToMultiByte(dword, dword, char*, int, char*, int, char*, void*)")
# 呼び出し: WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar)
# CodePage : DWORD -> "dword"
# dwFlags : DWORD -> "dword"
# lpWideCharStr : LPCWSTR -> "char*"
# cchWideChar : INT -> "int"
# lpMultiByteStr : LPSTR optional, out -> "char*"
# cbMultiByte : INT -> "int"
# lpDefaultChar : LPCSTR optional -> "char*"
# lpUsedDefaultChar : BOOL* optional, out -> "void*"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。

const std = @import("std");

extern "kernel32" fn WideCharToMultiByte(
    CodePage: u32, // DWORD
    dwFlags: u32, // DWORD
    lpWideCharStr: [*c]const u16, // LPCWSTR
    cchWideChar: i32, // INT
    lpMultiByteStr: [*c]u8, // LPSTR optional, out
    cbMultiByte: i32, // INT
    lpDefaultChar: [*c]const u8, // LPCSTR optional
    lpUsedDefaultChar: [*c]i32 // BOOL* optional, out
) callconv(std.os.windows.WINAPI) i32;

proc WideCharToMultiByte(
    CodePage: uint32,  # DWORD
    dwFlags: uint32,  # DWORD
    lpWideCharStr: WideCString,  # LPCWSTR
    cchWideChar: int32,  # INT
    lpMultiByteStr: ptr char,  # LPSTR optional, out
    cbMultiByte: int32,  # INT
    lpDefaultChar: cstring,  # LPCSTR optional
    lpUsedDefaultChar: ptr int32  # BOOL* optional, out
): int32 {.importc: "WideCharToMultiByte", stdcall, dynlib: "KERNEL32.dll".}

pragma(lib, "kernel32");
extern(Windows)
int WideCharToMultiByte(
    uint CodePage,   // DWORD
    uint dwFlags,   // DWORD
    const(wchar)* lpWideCharStr,   // LPCWSTR
    int cchWideChar,   // INT
    char* lpMultiByteStr,   // LPSTR optional, out
    int cbMultiByte,   // INT
    const(char)* lpDefaultChar,   // LPCSTR optional
    int* lpUsedDefaultChar   // BOOL* optional, out
);

ccall((:WideCharToMultiByte, "KERNEL32.dll"), stdcall, Int32,
      (UInt32, UInt32, Cwstring, Int32, Ptr{UInt8}, Int32, Cstring, Ptr{Int32}),
      CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar)
# CodePage : DWORD -> UInt32
# dwFlags : DWORD -> UInt32
# lpWideCharStr : LPCWSTR -> Cwstring
# cchWideChar : INT -> Int32
# lpMultiByteStr : LPSTR optional, out -> Ptr{UInt8}
# cbMultiByte : INT -> Int32
# lpDefaultChar : LPCSTR optional -> Cstring
# lpUsedDefaultChar : BOOL* optional, out -> Ptr{Int32}
# stdcall は 32bit のみ意味を持つ(x64 では無視)。

local ffi = require("ffi")
ffi.cdef[[
int32_t WideCharToMultiByte(
    uint32_t CodePage,
    uint32_t dwFlags,
    const uint16_t* lpWideCharStr,
    int32_t cchWideChar,
    char* lpMultiByteStr,
    int32_t cbMultiByte,
    const char* lpDefaultChar,
    int32_t* lpUsedDefaultChar);
]]
local kernel32 = ffi.load("kernel32")
-- kernel32.WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar)
-- CodePage : DWORD
-- dwFlags : DWORD
-- lpWideCharStr : LPCWSTR
-- cchWideChar : INT
-- lpMultiByteStr : LPSTR optional, out
-- cbMultiByte : INT
-- lpDefaultChar : LPCSTR optional
-- lpUsedDefaultChar : BOOL* optional, out
-- 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。

const koffi = require('koffi');
const lib = koffi.load('KERNEL32.dll');
const WideCharToMultiByte = lib.func('__stdcall', 'WideCharToMultiByte', 'int32_t', ['uint32_t', 'uint32_t', 'str16', 'int32_t', 'char *', 'int32_t', 'str', 'int32_t *']);
// WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar)
// CodePage : DWORD -> 'uint32_t'
// dwFlags : DWORD -> 'uint32_t'
// lpWideCharStr : LPCWSTR -> 'str16'
// cchWideChar : INT -> 'int32_t'
// lpMultiByteStr : LPSTR optional, out -> 'char *'
// cbMultiByte : INT -> 'int32_t'
// lpDefaultChar : LPCSTR optional -> 'str'
// lpUsedDefaultChar : BOOL* optional, out -> 'int32_t *'
// 出力ポインタは koffi.out(...) で包む。構造体は koffi.struct で定義。

const lib = Deno.dlopen("KERNEL32.dll", {
  WideCharToMultiByte: { parameters: ["u32", "u32", "buffer", "i32", "buffer", "i32", "buffer", "pointer"], result: "i32" },
});
// lib.symbols.WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar)
// CodePage : DWORD -> "u32"
// dwFlags : DWORD -> "u32"
// lpWideCharStr : LPCWSTR -> "buffer"
// cchWideChar : INT -> "i32"
// lpMultiByteStr : LPSTR optional, out -> "buffer"
// cbMultiByte : INT -> "i32"
// lpDefaultChar : LPCSTR optional -> "buffer"
// lpUsedDefaultChar : BOOL* optional, out -> "pointer"
// 文字列引数は "buffer"(NUL 終端のバイト列を Uint8Array で渡す)。
// 値渡し構造体は { struct: [ ...field types... ] } を使用。

<?php
$ffi = FFI::cdef(<<<C
int32_t WideCharToMultiByte(
    uint32_t CodePage,
    uint32_t dwFlags,
    const uint16_t* lpWideCharStr,
    int32_t cchWideChar,
    char* lpMultiByteStr,
    int32_t cbMultiByte,
    const char* lpDefaultChar,
    int32_t* lpUsedDefaultChar);
C, "KERNEL32.dll");
// $ffi->WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, lpMultiByteStr, cbMultiByte, lpDefaultChar, lpUsedDefaultChar);
// CodePage : DWORD
// dwFlags : DWORD
// lpWideCharStr : LPCWSTR
// cchWideChar : INT
// lpMultiByteStr : LPSTR optional, out
// cbMultiByte : INT
// lpDefaultChar : LPCSTR optional
// lpUsedDefaultChar : BOOL* optional, out
// 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。
// WINAPI(stdcall): x64 では呼出規約が統一されるため問題なし。x86 では __stdcall 対応のラッパが必要な場合あり。

import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.W32APIOptions;

public interface Kernel32 extends StdCallLibrary {
    Kernel32 INSTANCE = Native.load("kernel32", Kernel32.class);
    int WideCharToMultiByte(
        int CodePage,   // DWORD
        int dwFlags,   // DWORD
        WString lpWideCharStr,   // LPCWSTR
        int cchWideChar,   // INT
        byte[] lpMultiByteStr,   // LPSTR optional, out
        int cbMultiByte,   // INT
        String lpDefaultChar,   // LPCSTR optional
        IntByReference lpUsedDefaultChar   // BOOL* optional, out
    );
}

@[Link("kernel32")]
lib LibKERNEL32
  fun WideCharToMultiByte = WideCharToMultiByte(
    CodePage : UInt32,   # DWORD
    dwFlags : UInt32,   # DWORD
    lpWideCharStr : UInt16*,   # LPCWSTR
    cchWideChar : Int32,   # INT
    lpMultiByteStr : UInt8*,   # LPSTR optional, out
    cbMultiByte : Int32,   # INT
    lpDefaultChar : UInt8*,   # LPCSTR optional
    lpUsedDefaultChar : Int32*   # BOOL* optional, out
  ) : Int32
end
# 構造体/GUID/enum は lib 内に対応する型定義が必要。
# 呼出規約: x64 は規約統一のため OK。x86(32bit)は WINAPI=stdcall だが Crystal の fun に stdcall 付与構文がなく非対応。

import 'dart:ffi';
import 'package:ffi/ffi.dart';

typedef WideCharToMultiByteNative = Int32 Function(Uint32, Uint32, Pointer<Utf16>, Int32, Pointer<Utf8>, Int32, Pointer<Utf8>, Pointer<Int32>);
typedef WideCharToMultiByteDart = int Function(int, int, Pointer<Utf16>, int, Pointer<Utf8>, int, Pointer<Utf8>, Pointer<Int32>);
final WideCharToMultiByte = DynamicLibrary.open('KERNEL32.dll')
    .lookupFunction<WideCharToMultiByteNative, WideCharToMultiByteDart>('WideCharToMultiByte');
// CodePage : DWORD -> Uint32
// dwFlags : DWORD -> Uint32
// lpWideCharStr : LPCWSTR -> Pointer<Utf16>
// cchWideChar : INT -> Int32
// lpMultiByteStr : LPSTR optional, out -> Pointer<Utf8>
// cbMultiByte : INT -> Int32
// lpDefaultChar : LPCSTR optional -> Pointer<Utf8>
// lpUsedDefaultChar : BOOL* optional, out -> Pointer<Int32>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
function WideCharToMultiByte(
  CodePage: DWORD;   // DWORD
  dwFlags: DWORD;   // DWORD
  lpWideCharStr: PWideChar;   // LPCWSTR
  cchWideChar: Integer;   // INT
  lpMultiByteStr: PAnsiChar;   // LPSTR optional, out
  cbMultiByte: Integer;   // INT
  lpDefaultChar: PAnsiChar;   // LPCSTR optional
  lpUsedDefaultChar: Pointer   // BOOL* optional, out
): Integer; stdcall;
  external 'KERNEL32.dll' name 'WideCharToMultiByte';

import Foreign
import Foreign.C.Types
import Foreign.C.String

foreign import stdcall safe "WideCharToMultiByte"
  c_WideCharToMultiByte :: Word32 -> Word32 -> CWString -> Int32 -> CString -> Int32 -> CString -> Ptr CInt -> IO Int32
-- CodePage : DWORD -> Word32
-- dwFlags : DWORD -> Word32
-- lpWideCharStr : LPCWSTR -> CWString
-- cchWideChar : INT -> Int32
-- lpMultiByteStr : LPSTR optional, out -> CString
-- cbMultiByte : INT -> Int32
-- lpDefaultChar : LPCSTR optional -> CString
-- lpUsedDefaultChar : BOOL* optional, out -> Ptr CInt
-- 要 GHC(Windows)。stdcall は x64 では ccall として扱われる。ブロックする API は safe 呼び出し推奨。

open Ctypes
open Foreign

let widechartomultibyte =
  foreign "WideCharToMultiByte"
    (uint32_t @-> uint32_t @-> (ptr uint16_t) @-> int32_t @-> string @-> int32_t @-> string @-> (ptr int32_t) @-> returning int32_t)
(* CodePage : DWORD -> uint32_t *)
(* dwFlags : DWORD -> uint32_t *)
(* lpWideCharStr : LPCWSTR -> (ptr uint16_t) *)
(* cchWideChar : INT -> int32_t *)
(* lpMultiByteStr : LPSTR optional, out -> string *)
(* cbMultiByte : INT -> int32_t *)
(* lpDefaultChar : LPCSTR optional -> string *)
(* lpUsedDefaultChar : BOOL* optional, out -> (ptr int32_t) *)
(* foreign は cdecl 前提。x64 Windows では WINAPI と一致。構造体は ctypes structure を定義のこと。 *)

(cffi:define-foreign-library kernel32 (t "KERNEL32.dll"))
(cffi:use-foreign-library kernel32)

(cffi:defcfun ("WideCharToMultiByte" wide-char-to-multi-byte :convention :stdcall) :int32
  (code-page :uint32)   ; DWORD
  (dw-flags :uint32)   ; DWORD
  (lp-wide-char-str (:string :encoding :utf-16le))   ; LPCWSTR
  (cch-wide-char :int32)   ; INT
  (lp-multi-byte-str :pointer)   ; LPSTR optional, out
  (cb-multi-byte :int32)   ; INT
  (lp-default-char :string)   ; LPCSTR optional
  (lp-used-default-char :pointer))   ; BOOL* optional, out
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。

use Win32::API;
my $WideCharToMultiByte = Win32::API::More->new('KERNEL32',
    'int WideCharToMultiByte(DWORD CodePage, DWORD dwFlags, LPCWSTR lpWideCharStr, int cchWideChar, LPSTR lpMultiByteStr, int cbMultiByte, LPCSTR lpDefaultChar, LPVOID lpUsedDefaultChar)');
# my $ret = $WideCharToMultiByte->Call($CodePage, $dwFlags, $lpWideCharStr, $cchWideChar, $lpMultiByteStr, $cbMultiByte, $lpDefaultChar, $lpUsedDefaultChar);
# CodePage : DWORD -> DWORD
# dwFlags : DWORD -> DWORD
# lpWideCharStr : LPCWSTR -> LPCWSTR
# cchWideChar : INT -> int
# lpMultiByteStr : LPSTR optional, out -> LPSTR
# cbMultiByte : INT -> int
# lpDefaultChar : LPCSTR optional -> LPCSTR
# lpUsedDefaultChar : BOOL* optional, out -> LPVOID
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。