InitiateShutdownW

// ADVAPI32.dll  (Unicode / -W)
#include <windows.h>

DWORD InitiateShutdownW(
    LPWSTR lpMachineName,   // optional
    LPWSTR lpMessage,   // optional
    DWORD dwGracePeriod,
    SHUTDOWN_FLAGS dwShutdownFlags,
    SHUTDOWN_REASON dwReason
);

<DllImport("ADVAPI32.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function InitiateShutdownW(
    <MarshalAs(UnmanagedType.LPWStr)> lpMachineName As String,   ' LPWSTR optional
    <MarshalAs(UnmanagedType.LPWStr)> lpMessage As String,   ' LPWSTR optional
    dwGracePeriod As UInteger,   ' DWORD
    dwShutdownFlags As UInteger,   ' SHUTDOWN_FLAGS
    dwReason As UInteger   ' SHUTDOWN_REASON
) As UInteger
End Function

' lpMachineName : LPWSTR optional
' lpMessage : LPWSTR optional
' dwGracePeriod : DWORD
' dwShutdownFlags : SHUTDOWN_FLAGS
' dwReason : SHUTDOWN_REASON
Declare PtrSafe Function InitiateShutdownW Lib "advapi32" ( _
    ByVal lpMachineName As LongPtr, _
    ByVal lpMessage As LongPtr, _
    ByVal dwGracePeriod As Long, _
    ByVal dwShutdownFlags As Long, _
    ByVal dwReason As Long) As Long
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

InitiateShutdownW = ctypes.windll.advapi32.InitiateShutdownW
InitiateShutdownW.restype = wintypes.DWORD
InitiateShutdownW.argtypes = [
    wintypes.LPCWSTR,  # lpMachineName : LPWSTR optional
    wintypes.LPCWSTR,  # lpMessage : LPWSTR optional
    wintypes.DWORD,  # dwGracePeriod : DWORD
    wintypes.DWORD,  # dwShutdownFlags : SHUTDOWN_FLAGS
    wintypes.DWORD,  # dwReason : SHUTDOWN_REASON
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('ADVAPI32.dll')
InitiateShutdownW = Fiddle::Function.new(
  lib['InitiateShutdownW'],
  [
    Fiddle::TYPE_VOIDP,  # lpMachineName : LPWSTR optional
    Fiddle::TYPE_VOIDP,  # lpMessage : LPWSTR optional
    -Fiddle::TYPE_INT,  # dwGracePeriod : DWORD
    -Fiddle::TYPE_INT,  # dwShutdownFlags : SHUTDOWN_FLAGS
    -Fiddle::TYPE_INT,  # dwReason : SHUTDOWN_REASON
  ],
  -Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "advapi32")]
extern "system" {
    fn InitiateShutdownW(
        lpMachineName: *mut u16,  // LPWSTR optional
        lpMessage: *mut u16,  // LPWSTR optional
        dwGracePeriod: u32,  // DWORD
        dwShutdownFlags: u32,  // SHUTDOWN_FLAGS
        dwReason: u32  // SHUTDOWN_REASON
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("ADVAPI32.dll", CharSet = CharSet.Unicode)]
public static extern uint InitiateShutdownW([MarshalAs(UnmanagedType.LPWStr)] string lpMachineName, [MarshalAs(UnmanagedType.LPWStr)] string lpMessage, uint dwGracePeriod, uint dwShutdownFlags, uint dwReason);
"@
$api = Add-Type -MemberDefinition $sig -Name 'ADVAPI32_InitiateShutdownW' -Namespace Win32 -PassThru
# $api::InitiateShutdownW(lpMachineName, lpMessage, dwGracePeriod, dwShutdownFlags, dwReason)

#uselib "ADVAPI32.dll"
#func global InitiateShutdownW "InitiateShutdownW" wptr, wptr, wptr, wptr, wptr
; InitiateShutdownW lpMachineName, lpMessage, dwGracePeriod, dwShutdownFlags, dwReason   ; 戻り値は stat
; lpMachineName : LPWSTR optional -> "wptr"
; lpMessage : LPWSTR optional -> "wptr"
; dwGracePeriod : DWORD -> "wptr"
; dwShutdownFlags : SHUTDOWN_FLAGS -> "wptr"
; dwReason : SHUTDOWN_REASON -> "wptr"
; ※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 "ADVAPI32.dll"
#cfunc global InitiateShutdownW "InitiateShutdownW" wstr, wstr, int, int, int
; res = InitiateShutdownW(lpMachineName, lpMessage, dwGracePeriod, dwShutdownFlags, dwReason)
; lpMachineName : LPWSTR optional -> "wstr"
; lpMessage : LPWSTR optional -> "wstr"
; dwGracePeriod : DWORD -> "int"
; dwShutdownFlags : SHUTDOWN_FLAGS -> "int"
; dwReason : SHUTDOWN_REASON -> "int"

; DWORD InitiateShutdownW(LPWSTR lpMachineName, LPWSTR lpMessage, DWORD dwGracePeriod, SHUTDOWN_FLAGS dwShutdownFlags, SHUTDOWN_REASON dwReason)
#uselib "ADVAPI32.dll"
#cfunc global InitiateShutdownW "InitiateShutdownW" wstr, wstr, int, int, int
; res = InitiateShutdownW(lpMachineName, lpMessage, dwGracePeriod, dwShutdownFlags, dwReason)
; lpMachineName : LPWSTR optional -> "wstr"
; lpMessage : LPWSTR optional -> "wstr"
; dwGracePeriod : DWORD -> "int"
; dwShutdownFlags : SHUTDOWN_FLAGS -> "int"
; dwReason : SHUTDOWN_REASON -> "int"

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

var (
	advapi32 = windows.NewLazySystemDLL("ADVAPI32.dll")
	procInitiateShutdownW = advapi32.NewProc("InitiateShutdownW")
)

// lpMachineName (LPWSTR optional), lpMessage (LPWSTR optional), dwGracePeriod (DWORD), dwShutdownFlags (SHUTDOWN_FLAGS), dwReason (SHUTDOWN_REASON)
r1, _, err := procInitiateShutdownW.Call(
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpMachineName))),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpMessage))),
	uintptr(dwGracePeriod),
	uintptr(dwShutdownFlags),
	uintptr(dwReason),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function InitiateShutdownW(
  lpMachineName: PWideChar;   // LPWSTR optional
  lpMessage: PWideChar;   // LPWSTR optional
  dwGracePeriod: DWORD;   // DWORD
  dwShutdownFlags: DWORD;   // SHUTDOWN_FLAGS
  dwReason: DWORD   // SHUTDOWN_REASON
): DWORD; stdcall;
  external 'ADVAPI32.dll' name 'InitiateShutdownW';

result := DllCall("ADVAPI32\InitiateShutdownW"
    , "WStr", lpMachineName   ; LPWSTR optional
    , "WStr", lpMessage   ; LPWSTR optional
    , "UInt", dwGracePeriod   ; DWORD
    , "UInt", dwShutdownFlags   ; SHUTDOWN_FLAGS
    , "UInt", dwReason   ; SHUTDOWN_REASON
    , "UInt")   ; return: DWORD

●InitiateShutdownW(lpMachineName, lpMessage, dwGracePeriod, dwShutdownFlags, dwReason) = DLL("ADVAPI32.dll", "dword InitiateShutdownW(char*, char*, dword, dword, dword)")
# 呼び出し: InitiateShutdownW(lpMachineName, lpMessage, dwGracePeriod, dwShutdownFlags, dwReason)
# lpMachineName : LPWSTR optional -> "char*"
# lpMessage : LPWSTR optional -> "char*"
# dwGracePeriod : DWORD -> "dword"
# dwShutdownFlags : SHUTDOWN_FLAGS -> "dword"
# dwReason : SHUTDOWN_REASON -> "dword"
# 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)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。