MsiGetProductCodeA

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

DWORD MsiGetProductCodeA(
    LPCSTR szComponent,
    LPSTR lpBuf39
);

<DllImport("msi.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function MsiGetProductCodeA(
    <MarshalAs(UnmanagedType.LPStr)> szComponent As String,   ' LPCSTR
    <MarshalAs(UnmanagedType.LPStr)> lpBuf39 As System.Text.StringBuilder   ' LPSTR out
) As UInteger
End Function

' szComponent : LPCSTR
' lpBuf39 : LPSTR out
Declare PtrSafe Function MsiGetProductCodeA Lib "msi" ( _
    ByVal szComponent As String, _
    ByVal lpBuf39 As String) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

MsiGetProductCodeA = ctypes.windll.msi.MsiGetProductCodeA
MsiGetProductCodeA.restype = wintypes.DWORD
MsiGetProductCodeA.argtypes = [
    wintypes.LPCSTR,  # szComponent : LPCSTR
    wintypes.LPSTR,  # lpBuf39 : LPSTR out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('msi.dll')
MsiGetProductCodeA = Fiddle::Function.new(
  lib['MsiGetProductCodeA'],
  [
    Fiddle::TYPE_VOIDP,  # szComponent : LPCSTR
    Fiddle::TYPE_VOIDP,  # lpBuf39 : LPSTR out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "msi")]
extern "system" {
    fn MsiGetProductCodeA(
        szComponent: *const u8,  // LPCSTR
        lpBuf39: *mut u8  // LPSTR out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("msi.dll", CharSet = CharSet.Ansi)]
public static extern uint MsiGetProductCodeA([MarshalAs(UnmanagedType.LPStr)] string szComponent, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder lpBuf39);
"@
$api = Add-Type -MemberDefinition $sig -Name 'msi_MsiGetProductCodeA' -Namespace Win32 -PassThru
# $api::MsiGetProductCodeA(szComponent, lpBuf39)

#uselib "msi.dll"
#func global MsiGetProductCodeA "MsiGetProductCodeA" sptr, sptr
; MsiGetProductCodeA szComponent, varptr(lpBuf39)   ; 戻り値は stat
; szComponent : LPCSTR -> "sptr"
; lpBuf39 : LPSTR 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 MsiGetProductCodeA "MsiGetProductCodeA" str, var
; res = MsiGetProductCodeA(szComponent, lpBuf39)
; szComponent : LPCSTR -> "str"
; lpBuf39 : LPSTR 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 MsiGetProductCodeA(LPCSTR szComponent, LPSTR lpBuf39)
#uselib "msi.dll"
#cfunc global MsiGetProductCodeA "MsiGetProductCodeA" str, var
; res = MsiGetProductCodeA(szComponent, lpBuf39)
; szComponent : LPCSTR -> "str"
; lpBuf39 : LPSTR 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")
	procMsiGetProductCodeA = msi.NewProc("MsiGetProductCodeA")
)

// szComponent (LPCSTR), lpBuf39 (LPSTR out)
r1, _, err := procMsiGetProductCodeA.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(szComponent))),
	uintptr(lpBuf39),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function MsiGetProductCodeA(
  szComponent: PAnsiChar;   // LPCSTR
  lpBuf39: PAnsiChar   // LPSTR out
): DWORD; stdcall;
  external 'msi.dll' name 'MsiGetProductCodeA';

result := DllCall("msi\MsiGetProductCodeA"
    , "AStr", szComponent   ; LPCSTR
    , "Ptr", lpBuf39   ; LPSTR out
    , "UInt")   ; return: DWORD

●MsiGetProductCodeA(szComponent, lpBuf39) = DLL("msi.dll", "dword MsiGetProductCodeA(char*, char*)")
# 呼び出し: MsiGetProductCodeA(szComponent, lpBuf39)
# szComponent : LPCSTR -> "char*"
# lpBuf39 : LPSTR out -> "char*"
# 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)。