GetServiceDirectory

// api-ms-win-service-core-l1-1-4.dll
#include <windows.h>

DWORD GetServiceDirectory(
    SERVICE_STATUS_HANDLE hServiceStatus,
    SERVICE_DIRECTORY_TYPE eDirectoryType,
    LPWSTR lpPathBuffer,   // optional
    DWORD cchPathBufferLength,
    DWORD* lpcchRequiredBufferLength
);

<DllImport("api-ms-win-service-core-l1-1-4.dll", ExactSpelling:=True)>
Public Shared Function GetServiceDirectory(
    hServiceStatus As IntPtr,   ' SERVICE_STATUS_HANDLE
    eDirectoryType As Integer,   ' SERVICE_DIRECTORY_TYPE
    <MarshalAs(UnmanagedType.LPWStr)> lpPathBuffer As System.Text.StringBuilder,   ' LPWSTR optional, out
    cchPathBufferLength As UInteger,   ' DWORD
    <Out> ByRef lpcchRequiredBufferLength As UInteger   ' DWORD* out
) As UInteger
End Function

' hServiceStatus : SERVICE_STATUS_HANDLE
' eDirectoryType : SERVICE_DIRECTORY_TYPE
' lpPathBuffer : LPWSTR optional, out
' cchPathBufferLength : DWORD
' lpcchRequiredBufferLength : DWORD* out
Declare PtrSafe Function GetServiceDirectory Lib "api-ms-win-service-core-l1-1-4" ( _
    ByVal hServiceStatus As LongPtr, _
    ByVal eDirectoryType As Long, _
    ByVal lpPathBuffer As LongPtr, _
    ByVal cchPathBufferLength As Long, _
    ByRef lpcchRequiredBufferLength 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

GetServiceDirectory = ctypes.windll.LoadLibrary("api-ms-win-service-core-l1-1-4.dll").GetServiceDirectory
GetServiceDirectory.restype = wintypes.DWORD
GetServiceDirectory.argtypes = [
    wintypes.HANDLE,  # hServiceStatus : SERVICE_STATUS_HANDLE
    ctypes.c_int,  # eDirectoryType : SERVICE_DIRECTORY_TYPE
    wintypes.LPWSTR,  # lpPathBuffer : LPWSTR optional, out
    wintypes.DWORD,  # cchPathBufferLength : DWORD
    ctypes.POINTER(wintypes.DWORD),  # lpcchRequiredBufferLength : DWORD* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('api-ms-win-service-core-l1-1-4.dll')
GetServiceDirectory = Fiddle::Function.new(
  lib['GetServiceDirectory'],
  [
    Fiddle::TYPE_VOIDP,  # hServiceStatus : SERVICE_STATUS_HANDLE
    Fiddle::TYPE_INT,  # eDirectoryType : SERVICE_DIRECTORY_TYPE
    Fiddle::TYPE_VOIDP,  # lpPathBuffer : LPWSTR optional, out
    -Fiddle::TYPE_INT,  # cchPathBufferLength : DWORD
    Fiddle::TYPE_VOIDP,  # lpcchRequiredBufferLength : DWORD* out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "api-ms-win-service-core-l1-1-4")]
extern "system" {
    fn GetServiceDirectory(
        hServiceStatus: *mut core::ffi::c_void,  // SERVICE_STATUS_HANDLE
        eDirectoryType: i32,  // SERVICE_DIRECTORY_TYPE
        lpPathBuffer: *mut u16,  // LPWSTR optional, out
        cchPathBufferLength: u32,  // DWORD
        lpcchRequiredBufferLength: *mut u32  // DWORD* out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("api-ms-win-service-core-l1-1-4.dll")]
public static extern uint GetServiceDirectory(IntPtr hServiceStatus, int eDirectoryType, [MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder lpPathBuffer, uint cchPathBufferLength, out uint lpcchRequiredBufferLength);
"@
$api = Add-Type -MemberDefinition $sig -Name 'api-ms-win-service-core-l1-1-4_GetServiceDirectory' -Namespace Win32 -PassThru
# $api::GetServiceDirectory(hServiceStatus, eDirectoryType, lpPathBuffer, cchPathBufferLength, lpcchRequiredBufferLength)

#uselib "api-ms-win-service-core-l1-1-4.dll"
#func global GetServiceDirectory "GetServiceDirectory" sptr, sptr, sptr, sptr, sptr
; GetServiceDirectory hServiceStatus, eDirectoryType, varptr(lpPathBuffer), cchPathBufferLength, varptr(lpcchRequiredBufferLength)   ; 戻り値は stat
; hServiceStatus : SERVICE_STATUS_HANDLE -> "sptr"
; eDirectoryType : SERVICE_DIRECTORY_TYPE -> "sptr"
; lpPathBuffer : LPWSTR optional, out -> "sptr"
; cchPathBufferLength : DWORD -> "sptr"
; lpcchRequiredBufferLength : DWORD* 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。

#uselib "api-ms-win-service-core-l1-1-4.dll"
#cfunc global GetServiceDirectory "GetServiceDirectory" sptr, int, var, int, var
; res = GetServiceDirectory(hServiceStatus, eDirectoryType, lpPathBuffer, cchPathBufferLength, lpcchRequiredBufferLength)
; hServiceStatus : SERVICE_STATUS_HANDLE -> "sptr"
; eDirectoryType : SERVICE_DIRECTORY_TYPE -> "int"
; lpPathBuffer : LPWSTR optional, out -> "var"
; cchPathBufferLength : DWORD -> "int"
; lpcchRequiredBufferLength : DWORD* out -> "var"
; ※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。

; DWORD GetServiceDirectory(SERVICE_STATUS_HANDLE hServiceStatus, SERVICE_DIRECTORY_TYPE eDirectoryType, LPWSTR lpPathBuffer, DWORD cchPathBufferLength, DWORD* lpcchRequiredBufferLength)
#uselib "api-ms-win-service-core-l1-1-4.dll"
#cfunc global GetServiceDirectory "GetServiceDirectory" intptr, int, var, int, var
; res = GetServiceDirectory(hServiceStatus, eDirectoryType, lpPathBuffer, cchPathBufferLength, lpcchRequiredBufferLength)
; hServiceStatus : SERVICE_STATUS_HANDLE -> "intptr"
; eDirectoryType : SERVICE_DIRECTORY_TYPE -> "int"
; lpPathBuffer : LPWSTR optional, out -> "var"
; cchPathBufferLength : DWORD -> "int"
; lpcchRequiredBufferLength : DWORD* out -> "var"
; ※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 (
	api_ms_win_service_core_l1_1_4 = windows.NewLazySystemDLL("api-ms-win-service-core-l1-1-4.dll")
	procGetServiceDirectory = api_ms_win_service_core_l1_1_4.NewProc("GetServiceDirectory")
)

// hServiceStatus (SERVICE_STATUS_HANDLE), eDirectoryType (SERVICE_DIRECTORY_TYPE), lpPathBuffer (LPWSTR optional, out), cchPathBufferLength (DWORD), lpcchRequiredBufferLength (DWORD* out)
r1, _, err := procGetServiceDirectory.Call(
	uintptr(hServiceStatus),
	uintptr(eDirectoryType),
	uintptr(lpPathBuffer),
	uintptr(cchPathBufferLength),
	uintptr(lpcchRequiredBufferLength),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function GetServiceDirectory(
  hServiceStatus: THandle;   // SERVICE_STATUS_HANDLE
  eDirectoryType: Integer;   // SERVICE_DIRECTORY_TYPE
  lpPathBuffer: PWideChar;   // LPWSTR optional, out
  cchPathBufferLength: DWORD;   // DWORD
  lpcchRequiredBufferLength: Pointer   // DWORD* out
): DWORD; stdcall;
  external 'api-ms-win-service-core-l1-1-4.dll' name 'GetServiceDirectory';

result := DllCall("api-ms-win-service-core-l1-1-4\GetServiceDirectory"
    , "Ptr", hServiceStatus   ; SERVICE_STATUS_HANDLE
    , "Int", eDirectoryType   ; SERVICE_DIRECTORY_TYPE
    , "Ptr", lpPathBuffer   ; LPWSTR optional, out
    , "UInt", cchPathBufferLength   ; DWORD
    , "Ptr", lpcchRequiredBufferLength   ; DWORD* out
    , "UInt")   ; return: DWORD

●GetServiceDirectory(hServiceStatus, eDirectoryType, lpPathBuffer, cchPathBufferLength, lpcchRequiredBufferLength) = DLL("api-ms-win-service-core-l1-1-4.dll", "dword GetServiceDirectory(void*, int, char*, dword, void*)")
# 呼び出し: GetServiceDirectory(hServiceStatus, eDirectoryType, lpPathBuffer, cchPathBufferLength, lpcchRequiredBufferLength)
# hServiceStatus : SERVICE_STATUS_HANDLE -> "void*"
# eDirectoryType : SERVICE_DIRECTORY_TYPE -> "int"
# lpPathBuffer : LPWSTR optional, out -> "char*"
# cchPathBufferLength : DWORD -> "dword"
# lpcchRequiredBufferLength : DWORD* 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)。