MsiEnumFeaturesA

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

DWORD MsiEnumFeaturesA(
    LPCSTR szProduct,
    DWORD iFeatureIndex,
    LPSTR lpFeatureBuf,
    LPSTR lpParentBuf   // optional
);

<DllImport("msi.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function MsiEnumFeaturesA(
    <MarshalAs(UnmanagedType.LPStr)> szProduct As String,   ' LPCSTR
    iFeatureIndex As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPStr)> lpFeatureBuf As System.Text.StringBuilder,   ' LPSTR out
    <MarshalAs(UnmanagedType.LPStr)> lpParentBuf As System.Text.StringBuilder   ' LPSTR optional, out
) As UInteger
End Function

' szProduct : LPCSTR
' iFeatureIndex : DWORD
' lpFeatureBuf : LPSTR out
' lpParentBuf : LPSTR optional, out
Declare PtrSafe Function MsiEnumFeaturesA Lib "msi" ( _
    ByVal szProduct As String, _
    ByVal iFeatureIndex As Long, _
    ByVal lpFeatureBuf As String, _
    ByVal lpParentBuf 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

MsiEnumFeaturesA = ctypes.windll.msi.MsiEnumFeaturesA
MsiEnumFeaturesA.restype = wintypes.DWORD
MsiEnumFeaturesA.argtypes = [
    wintypes.LPCSTR,  # szProduct : LPCSTR
    wintypes.DWORD,  # iFeatureIndex : DWORD
    wintypes.LPSTR,  # lpFeatureBuf : LPSTR out
    wintypes.LPSTR,  # lpParentBuf : LPSTR optional, out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('msi.dll')
MsiEnumFeaturesA = Fiddle::Function.new(
  lib['MsiEnumFeaturesA'],
  [
    Fiddle::TYPE_VOIDP,  # szProduct : LPCSTR
    -Fiddle::TYPE_INT,  # iFeatureIndex : DWORD
    Fiddle::TYPE_VOIDP,  # lpFeatureBuf : LPSTR out
    Fiddle::TYPE_VOIDP,  # lpParentBuf : LPSTR optional, out
  ],
  -Fiddle::TYPE_INT)

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

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

#uselib "msi.dll"
#func global MsiEnumFeaturesA "MsiEnumFeaturesA" sptr, sptr, sptr, sptr
; MsiEnumFeaturesA szProduct, iFeatureIndex, varptr(lpFeatureBuf), varptr(lpParentBuf)   ; 戻り値は stat
; szProduct : LPCSTR -> "sptr"
; iFeatureIndex : DWORD -> "sptr"
; lpFeatureBuf : LPSTR out -> "sptr"
; lpParentBuf : LPSTR optional, 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 MsiEnumFeaturesA "MsiEnumFeaturesA" str, int, var, var
; res = MsiEnumFeaturesA(szProduct, iFeatureIndex, lpFeatureBuf, lpParentBuf)
; szProduct : LPCSTR -> "str"
; iFeatureIndex : DWORD -> "int"
; lpFeatureBuf : LPSTR out -> "var"
; lpParentBuf : LPSTR optional, 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 MsiEnumFeaturesA(LPCSTR szProduct, DWORD iFeatureIndex, LPSTR lpFeatureBuf, LPSTR lpParentBuf)
#uselib "msi.dll"
#cfunc global MsiEnumFeaturesA "MsiEnumFeaturesA" str, int, var, var
; res = MsiEnumFeaturesA(szProduct, iFeatureIndex, lpFeatureBuf, lpParentBuf)
; szProduct : LPCSTR -> "str"
; iFeatureIndex : DWORD -> "int"
; lpFeatureBuf : LPSTR out -> "var"
; lpParentBuf : LPSTR optional, 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")
	procMsiEnumFeaturesA = msi.NewProc("MsiEnumFeaturesA")
)

// szProduct (LPCSTR), iFeatureIndex (DWORD), lpFeatureBuf (LPSTR out), lpParentBuf (LPSTR optional, out)
r1, _, err := procMsiEnumFeaturesA.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(szProduct))),
	uintptr(iFeatureIndex),
	uintptr(lpFeatureBuf),
	uintptr(lpParentBuf),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function MsiEnumFeaturesA(
  szProduct: PAnsiChar;   // LPCSTR
  iFeatureIndex: DWORD;   // DWORD
  lpFeatureBuf: PAnsiChar;   // LPSTR out
  lpParentBuf: PAnsiChar   // LPSTR optional, out
): DWORD; stdcall;
  external 'msi.dll' name 'MsiEnumFeaturesA';

result := DllCall("msi\MsiEnumFeaturesA"
    , "AStr", szProduct   ; LPCSTR
    , "UInt", iFeatureIndex   ; DWORD
    , "Ptr", lpFeatureBuf   ; LPSTR out
    , "Ptr", lpParentBuf   ; LPSTR optional, out
    , "UInt")   ; return: DWORD

●MsiEnumFeaturesA(szProduct, iFeatureIndex, lpFeatureBuf, lpParentBuf) = DLL("msi.dll", "dword MsiEnumFeaturesA(char*, dword, char*, char*)")
# 呼び出し: MsiEnumFeaturesA(szProduct, iFeatureIndex, lpFeatureBuf, lpParentBuf)
# szProduct : LPCSTR -> "char*"
# iFeatureIndex : DWORD -> "dword"
# lpFeatureBuf : LPSTR out -> "char*"
# lpParentBuf : LPSTR optional, 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)。