MsiGetProductInfoExA

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

DWORD MsiGetProductInfoExA(
    LPCSTR szProductCode,
    LPCSTR szUserSid,   // optional
    MSIINSTALLCONTEXT dwContext,
    LPCSTR szProperty,
    LPSTR szValue,   // optional
    DWORD* pcchValue   // optional
);

<DllImport("msi.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function MsiGetProductInfoExA(
    <MarshalAs(UnmanagedType.LPStr)> szProductCode As String,   ' LPCSTR
    <MarshalAs(UnmanagedType.LPStr)> szUserSid As String,   ' LPCSTR optional
    dwContext As Integer,   ' MSIINSTALLCONTEXT
    <MarshalAs(UnmanagedType.LPStr)> szProperty As String,   ' LPCSTR
    <MarshalAs(UnmanagedType.LPStr)> szValue As System.Text.StringBuilder,   ' LPSTR optional, out
    pcchValue As IntPtr   ' DWORD* optional, in/out
) As UInteger
End Function

' szProductCode : LPCSTR
' szUserSid : LPCSTR optional
' dwContext : MSIINSTALLCONTEXT
' szProperty : LPCSTR
' szValue : LPSTR optional, out
' pcchValue : DWORD* optional, in/out
Declare PtrSafe Function MsiGetProductInfoExA Lib "msi" ( _
    ByVal szProductCode As String, _
    ByVal szUserSid As String, _
    ByVal dwContext As Long, _
    ByVal szProperty As String, _
    ByVal szValue As String, _
    ByVal pcchValue 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

MsiGetProductInfoExA = ctypes.windll.msi.MsiGetProductInfoExA
MsiGetProductInfoExA.restype = wintypes.DWORD
MsiGetProductInfoExA.argtypes = [
    wintypes.LPCSTR,  # szProductCode : LPCSTR
    wintypes.LPCSTR,  # szUserSid : LPCSTR optional
    ctypes.c_int,  # dwContext : MSIINSTALLCONTEXT
    wintypes.LPCSTR,  # szProperty : LPCSTR
    wintypes.LPSTR,  # szValue : LPSTR optional, out
    ctypes.POINTER(wintypes.DWORD),  # pcchValue : DWORD* optional, in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('msi.dll')
MsiGetProductInfoExA = Fiddle::Function.new(
  lib['MsiGetProductInfoExA'],
  [
    Fiddle::TYPE_VOIDP,  # szProductCode : LPCSTR
    Fiddle::TYPE_VOIDP,  # szUserSid : LPCSTR optional
    Fiddle::TYPE_INT,  # dwContext : MSIINSTALLCONTEXT
    Fiddle::TYPE_VOIDP,  # szProperty : LPCSTR
    Fiddle::TYPE_VOIDP,  # szValue : LPSTR optional, out
    Fiddle::TYPE_VOIDP,  # pcchValue : DWORD* optional, in/out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "msi")]
extern "system" {
    fn MsiGetProductInfoExA(
        szProductCode: *const u8,  // LPCSTR
        szUserSid: *const u8,  // LPCSTR optional
        dwContext: i32,  // MSIINSTALLCONTEXT
        szProperty: *const u8,  // LPCSTR
        szValue: *mut u8,  // LPSTR optional, out
        pcchValue: *mut u32  // DWORD* optional, in/out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("msi.dll", CharSet = CharSet.Ansi)]
public static extern uint MsiGetProductInfoExA([MarshalAs(UnmanagedType.LPStr)] string szProductCode, [MarshalAs(UnmanagedType.LPStr)] string szUserSid, int dwContext, [MarshalAs(UnmanagedType.LPStr)] string szProperty, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder szValue, IntPtr pcchValue);
"@
$api = Add-Type -MemberDefinition $sig -Name 'msi_MsiGetProductInfoExA' -Namespace Win32 -PassThru
# $api::MsiGetProductInfoExA(szProductCode, szUserSid, dwContext, szProperty, szValue, pcchValue)

#uselib "msi.dll"
#func global MsiGetProductInfoExA "MsiGetProductInfoExA" sptr, sptr, sptr, sptr, sptr, sptr
; MsiGetProductInfoExA szProductCode, szUserSid, dwContext, szProperty, varptr(szValue), varptr(pcchValue)   ; 戻り値は stat
; szProductCode : LPCSTR -> "sptr"
; szUserSid : LPCSTR optional -> "sptr"
; dwContext : MSIINSTALLCONTEXT -> "sptr"
; szProperty : LPCSTR -> "sptr"
; szValue : LPSTR optional, out -> "sptr"
; pcchValue : DWORD* optional, in/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 "msi.dll"
#cfunc global MsiGetProductInfoExA "MsiGetProductInfoExA" str, str, int, str, var, var
; res = MsiGetProductInfoExA(szProductCode, szUserSid, dwContext, szProperty, szValue, pcchValue)
; szProductCode : LPCSTR -> "str"
; szUserSid : LPCSTR optional -> "str"
; dwContext : MSIINSTALLCONTEXT -> "int"
; szProperty : LPCSTR -> "str"
; szValue : LPSTR optional, out -> "var"
; pcchValue : DWORD* optional, in/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 MsiGetProductInfoExA(LPCSTR szProductCode, LPCSTR szUserSid, MSIINSTALLCONTEXT dwContext, LPCSTR szProperty, LPSTR szValue, DWORD* pcchValue)
#uselib "msi.dll"
#cfunc global MsiGetProductInfoExA "MsiGetProductInfoExA" str, str, int, str, var, var
; res = MsiGetProductInfoExA(szProductCode, szUserSid, dwContext, szProperty, szValue, pcchValue)
; szProductCode : LPCSTR -> "str"
; szUserSid : LPCSTR optional -> "str"
; dwContext : MSIINSTALLCONTEXT -> "int"
; szProperty : LPCSTR -> "str"
; szValue : LPSTR optional, out -> "var"
; pcchValue : DWORD* optional, in/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 (
	msi = windows.NewLazySystemDLL("msi.dll")
	procMsiGetProductInfoExA = msi.NewProc("MsiGetProductInfoExA")
)

// szProductCode (LPCSTR), szUserSid (LPCSTR optional), dwContext (MSIINSTALLCONTEXT), szProperty (LPCSTR), szValue (LPSTR optional, out), pcchValue (DWORD* optional, in/out)
r1, _, err := procMsiGetProductInfoExA.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(szProductCode))),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(szUserSid))),
	uintptr(dwContext),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(szProperty))),
	uintptr(szValue),
	uintptr(pcchValue),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function MsiGetProductInfoExA(
  szProductCode: PAnsiChar;   // LPCSTR
  szUserSid: PAnsiChar;   // LPCSTR optional
  dwContext: Integer;   // MSIINSTALLCONTEXT
  szProperty: PAnsiChar;   // LPCSTR
  szValue: PAnsiChar;   // LPSTR optional, out
  pcchValue: Pointer   // DWORD* optional, in/out
): DWORD; stdcall;
  external 'msi.dll' name 'MsiGetProductInfoExA';

result := DllCall("msi\MsiGetProductInfoExA"
    , "AStr", szProductCode   ; LPCSTR
    , "AStr", szUserSid   ; LPCSTR optional
    , "Int", dwContext   ; MSIINSTALLCONTEXT
    , "AStr", szProperty   ; LPCSTR
    , "Ptr", szValue   ; LPSTR optional, out
    , "Ptr", pcchValue   ; DWORD* optional, in/out
    , "UInt")   ; return: DWORD

●MsiGetProductInfoExA(szProductCode, szUserSid, dwContext, szProperty, szValue, pcchValue) = DLL("msi.dll", "dword MsiGetProductInfoExA(char*, char*, int, char*, char*, void*)")
# 呼び出し: MsiGetProductInfoExA(szProductCode, szUserSid, dwContext, szProperty, szValue, pcchValue)
# szProductCode : LPCSTR -> "char*"
# szUserSid : LPCSTR optional -> "char*"
# dwContext : MSIINSTALLCONTEXT -> "int"
# szProperty : LPCSTR -> "char*"
# szValue : LPSTR optional, out -> "char*"
# pcchValue : DWORD* optional, in/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)。