GetSystemDefaultLocaleName

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

INT GetSystemDefaultLocaleName(
    LPWSTR lpLocaleName,
    INT cchLocaleName
);

<DllImport("KERNEL32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function GetSystemDefaultLocaleName(
    <MarshalAs(UnmanagedType.LPWStr)> lpLocaleName As System.Text.StringBuilder,   ' LPWSTR out
    cchLocaleName As Integer   ' INT
) As Integer
End Function

' lpLocaleName : LPWSTR out
' cchLocaleName : INT
Declare PtrSafe Function GetSystemDefaultLocaleName Lib "kernel32" ( _
    ByVal lpLocaleName As LongPtr, _
    ByVal cchLocaleName As Long) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

GetSystemDefaultLocaleName = ctypes.windll.kernel32.GetSystemDefaultLocaleName
GetSystemDefaultLocaleName.restype = ctypes.c_int
GetSystemDefaultLocaleName.argtypes = [
    wintypes.LPWSTR,  # lpLocaleName : LPWSTR out
    ctypes.c_int,  # cchLocaleName : INT
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
GetSystemDefaultLocaleName = Fiddle::Function.new(
  lib['GetSystemDefaultLocaleName'],
  [
    Fiddle::TYPE_VOIDP,  # lpLocaleName : LPWSTR out
    Fiddle::TYPE_INT,  # cchLocaleName : INT
  ],
  Fiddle::TYPE_INT)

#[link(name = "kernel32")]
extern "system" {
    fn GetSystemDefaultLocaleName(
        lpLocaleName: *mut u16,  // LPWSTR out
        cchLocaleName: i32  // INT
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("KERNEL32.dll", SetLastError = true)]
public static extern int GetSystemDefaultLocaleName([MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder lpLocaleName, int cchLocaleName);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_GetSystemDefaultLocaleName' -Namespace Win32 -PassThru
# $api::GetSystemDefaultLocaleName(lpLocaleName, cchLocaleName)

#uselib "KERNEL32.dll"
#func global GetSystemDefaultLocaleName "GetSystemDefaultLocaleName" sptr, sptr
; GetSystemDefaultLocaleName varptr(lpLocaleName), cchLocaleName   ; 戻り値は stat
; lpLocaleName : LPWSTR out -> "sptr"
; cchLocaleName : INT -> "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。

#uselib "KERNEL32.dll"
#cfunc global GetSystemDefaultLocaleName "GetSystemDefaultLocaleName" var, int
; res = GetSystemDefaultLocaleName(lpLocaleName, cchLocaleName)
; lpLocaleName : LPWSTR out -> "var"
; cchLocaleName : INT -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; INT GetSystemDefaultLocaleName(LPWSTR lpLocaleName, INT cchLocaleName)
#uselib "KERNEL32.dll"
#cfunc global GetSystemDefaultLocaleName "GetSystemDefaultLocaleName" var, int
; res = GetSystemDefaultLocaleName(lpLocaleName, cchLocaleName)
; lpLocaleName : LPWSTR out -> "var"
; cchLocaleName : INT -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

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

var (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	procGetSystemDefaultLocaleName = kernel32.NewProc("GetSystemDefaultLocaleName")
)

// lpLocaleName (LPWSTR out), cchLocaleName (INT)
r1, _, err := procGetSystemDefaultLocaleName.Call(
	uintptr(lpLocaleName),
	uintptr(cchLocaleName),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function GetSystemDefaultLocaleName(
  lpLocaleName: PWideChar;   // LPWSTR out
  cchLocaleName: Integer   // INT
): Integer; stdcall;
  external 'KERNEL32.dll' name 'GetSystemDefaultLocaleName';

result := DllCall("KERNEL32\GetSystemDefaultLocaleName"
    , "Ptr", lpLocaleName   ; LPWSTR out
    , "Int", cchLocaleName   ; INT
    , "Int")   ; return: INT

●GetSystemDefaultLocaleName(lpLocaleName, cchLocaleName) = DLL("KERNEL32.dll", "int GetSystemDefaultLocaleName(char*, int)")
# 呼び出し: GetSystemDefaultLocaleName(lpLocaleName, cchLocaleName)
# lpLocaleName : LPWSTR out -> "char*"
# cchLocaleName : INT -> "int"
# 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)。