GetFirmwareEnvironmentVariableA

// KERNEL32.dll  (ANSI / -A)
#include <windows.h>

DWORD GetFirmwareEnvironmentVariableA(
    LPCSTR lpName,
    LPCSTR lpGuid,
    void* pBuffer,   // optional
    DWORD nSize
);

<DllImport("KERNEL32.dll", CharSet:=CharSet.Ansi, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function GetFirmwareEnvironmentVariableA(
    <MarshalAs(UnmanagedType.LPStr)> lpName As String,   ' LPCSTR
    <MarshalAs(UnmanagedType.LPStr)> lpGuid As String,   ' LPCSTR
    pBuffer As IntPtr,   ' void* optional, out
    nSize As UInteger   ' DWORD
) As UInteger
End Function

' lpName : LPCSTR
' lpGuid : LPCSTR
' pBuffer : void* optional, out
' nSize : DWORD
Declare PtrSafe Function GetFirmwareEnvironmentVariableA Lib "kernel32" ( _
    ByVal lpName As String, _
    ByVal lpGuid As String, _
    ByVal pBuffer As LongPtr, _
    ByVal nSize 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

GetFirmwareEnvironmentVariableA = ctypes.windll.kernel32.GetFirmwareEnvironmentVariableA
GetFirmwareEnvironmentVariableA.restype = wintypes.DWORD
GetFirmwareEnvironmentVariableA.argtypes = [
    wintypes.LPCSTR,  # lpName : LPCSTR
    wintypes.LPCSTR,  # lpGuid : LPCSTR
    ctypes.POINTER(None),  # pBuffer : void* optional, out
    wintypes.DWORD,  # nSize : DWORD
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
GetFirmwareEnvironmentVariableA = Fiddle::Function.new(
  lib['GetFirmwareEnvironmentVariableA'],
  [
    Fiddle::TYPE_VOIDP,  # lpName : LPCSTR
    Fiddle::TYPE_VOIDP,  # lpGuid : LPCSTR
    Fiddle::TYPE_VOIDP,  # pBuffer : void* optional, out
    -Fiddle::TYPE_INT,  # nSize : DWORD
  ],
  -Fiddle::TYPE_INT)

#[link(name = "kernel32")]
extern "system" {
    fn GetFirmwareEnvironmentVariableA(
        lpName: *const u8,  // LPCSTR
        lpGuid: *const u8,  // LPCSTR
        pBuffer: *mut (),  // void* optional, out
        nSize: u32  // DWORD
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("KERNEL32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
public static extern uint GetFirmwareEnvironmentVariableA([MarshalAs(UnmanagedType.LPStr)] string lpName, [MarshalAs(UnmanagedType.LPStr)] string lpGuid, IntPtr pBuffer, uint nSize);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_GetFirmwareEnvironmentVariableA' -Namespace Win32 -PassThru
# $api::GetFirmwareEnvironmentVariableA(lpName, lpGuid, pBuffer, nSize)

#uselib "KERNEL32.dll"
#func global GetFirmwareEnvironmentVariableA "GetFirmwareEnvironmentVariableA" sptr, sptr, sptr, sptr
; GetFirmwareEnvironmentVariableA lpName, lpGuid, pBuffer, nSize   ; 戻り値は stat
; lpName : LPCSTR -> "sptr"
; lpGuid : LPCSTR -> "sptr"
; pBuffer : void* optional, out -> "sptr"
; nSize : DWORD -> "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 GetFirmwareEnvironmentVariableA "GetFirmwareEnvironmentVariableA" str, str, sptr, int
; res = GetFirmwareEnvironmentVariableA(lpName, lpGuid, pBuffer, nSize)
; lpName : LPCSTR -> "str"
; lpGuid : LPCSTR -> "str"
; pBuffer : void* optional, out -> "sptr"
; nSize : DWORD -> "int"

; DWORD GetFirmwareEnvironmentVariableA(LPCSTR lpName, LPCSTR lpGuid, void* pBuffer, DWORD nSize)
#uselib "KERNEL32.dll"
#cfunc global GetFirmwareEnvironmentVariableA "GetFirmwareEnvironmentVariableA" str, str, intptr, int
; res = GetFirmwareEnvironmentVariableA(lpName, lpGuid, pBuffer, nSize)
; lpName : LPCSTR -> "str"
; lpGuid : LPCSTR -> "str"
; pBuffer : void* optional, out -> "intptr"
; nSize : DWORD -> "int"

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

var (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	procGetFirmwareEnvironmentVariableA = kernel32.NewProc("GetFirmwareEnvironmentVariableA")
)

// lpName (LPCSTR), lpGuid (LPCSTR), pBuffer (void* optional, out), nSize (DWORD)
r1, _, err := procGetFirmwareEnvironmentVariableA.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(lpName))),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(lpGuid))),
	uintptr(pBuffer),
	uintptr(nSize),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function GetFirmwareEnvironmentVariableA(
  lpName: PAnsiChar;   // LPCSTR
  lpGuid: PAnsiChar;   // LPCSTR
  pBuffer: Pointer;   // void* optional, out
  nSize: DWORD   // DWORD
): DWORD; stdcall;
  external 'KERNEL32.dll' name 'GetFirmwareEnvironmentVariableA';

result := DllCall("KERNEL32\GetFirmwareEnvironmentVariableA"
    , "AStr", lpName   ; LPCSTR
    , "AStr", lpGuid   ; LPCSTR
    , "Ptr", pBuffer   ; void* optional, out
    , "UInt", nSize   ; DWORD
    , "UInt")   ; return: DWORD

●GetFirmwareEnvironmentVariableA(lpName, lpGuid, pBuffer, nSize) = DLL("KERNEL32.dll", "dword GetFirmwareEnvironmentVariableA(char*, char*, void*, dword)")
# 呼び出し: GetFirmwareEnvironmentVariableA(lpName, lpGuid, pBuffer, nSize)
# lpName : LPCSTR -> "char*"
# lpGuid : LPCSTR -> "char*"
# pBuffer : void* optional, out -> "void*"
# nSize : DWORD -> "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)。