SHRegEnumUSKeyA

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

WIN32_ERROR SHRegEnumUSKeyA(
    INT_PTR hUSKey,
    DWORD dwIndex,
    LPSTR pszName,
    DWORD* pcchName,
    SHREGENUM_FLAGS enumRegFlags
);

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function SHRegEnumUSKeyA(
    hUSKey As IntPtr,   ' INT_PTR
    dwIndex As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPStr)> pszName As System.Text.StringBuilder,   ' LPSTR out
    ByRef pcchName As UInteger,   ' DWORD* in/out
    enumRegFlags As Integer   ' SHREGENUM_FLAGS
) As UInteger
End Function

' hUSKey : INT_PTR
' dwIndex : DWORD
' pszName : LPSTR out
' pcchName : DWORD* in/out
' enumRegFlags : SHREGENUM_FLAGS
Declare PtrSafe Function SHRegEnumUSKeyA Lib "shlwapi" ( _
    ByVal hUSKey As LongPtr, _
    ByVal dwIndex As Long, _
    ByVal pszName As String, _
    ByRef pcchName As Long, _
    ByVal enumRegFlags 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

SHRegEnumUSKeyA = ctypes.windll.shlwapi.SHRegEnumUSKeyA
SHRegEnumUSKeyA.restype = wintypes.DWORD
SHRegEnumUSKeyA.argtypes = [
    ctypes.c_ssize_t,  # hUSKey : INT_PTR
    wintypes.DWORD,  # dwIndex : DWORD
    wintypes.LPSTR,  # pszName : LPSTR out
    ctypes.POINTER(wintypes.DWORD),  # pcchName : DWORD* in/out
    ctypes.c_int,  # enumRegFlags : SHREGENUM_FLAGS
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHLWAPI.dll')
SHRegEnumUSKeyA = Fiddle::Function.new(
  lib['SHRegEnumUSKeyA'],
  [
    Fiddle::TYPE_INTPTR_T,  # hUSKey : INT_PTR
    -Fiddle::TYPE_INT,  # dwIndex : DWORD
    Fiddle::TYPE_VOIDP,  # pszName : LPSTR out
    Fiddle::TYPE_VOIDP,  # pcchName : DWORD* in/out
    Fiddle::TYPE_INT,  # enumRegFlags : SHREGENUM_FLAGS
  ],
  -Fiddle::TYPE_INT)

#[link(name = "shlwapi")]
extern "system" {
    fn SHRegEnumUSKeyA(
        hUSKey: isize,  // INT_PTR
        dwIndex: u32,  // DWORD
        pszName: *mut u8,  // LPSTR out
        pcchName: *mut u32,  // DWORD* in/out
        enumRegFlags: i32  // SHREGENUM_FLAGS
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHLWAPI.dll", CharSet = CharSet.Ansi)]
public static extern uint SHRegEnumUSKeyA(IntPtr hUSKey, uint dwIndex, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder pszName, ref uint pcchName, int enumRegFlags);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_SHRegEnumUSKeyA' -Namespace Win32 -PassThru
# $api::SHRegEnumUSKeyA(hUSKey, dwIndex, pszName, pcchName, enumRegFlags)

#uselib "SHLWAPI.dll"
#func global SHRegEnumUSKeyA "SHRegEnumUSKeyA" sptr, sptr, sptr, sptr, sptr
; SHRegEnumUSKeyA hUSKey, dwIndex, varptr(pszName), varptr(pcchName), enumRegFlags   ; 戻り値は stat
; hUSKey : INT_PTR -> "sptr"
; dwIndex : DWORD -> "sptr"
; pszName : LPSTR out -> "sptr"
; pcchName : DWORD* in/out -> "sptr"
; enumRegFlags : SHREGENUM_FLAGS -> "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 "SHLWAPI.dll"
#cfunc global SHRegEnumUSKeyA "SHRegEnumUSKeyA" sptr, int, var, var, int
; res = SHRegEnumUSKeyA(hUSKey, dwIndex, pszName, pcchName, enumRegFlags)
; hUSKey : INT_PTR -> "sptr"
; dwIndex : DWORD -> "int"
; pszName : LPSTR out -> "var"
; pcchName : DWORD* in/out -> "var"
; enumRegFlags : SHREGENUM_FLAGS -> "int"
; ※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。

; WIN32_ERROR SHRegEnumUSKeyA(INT_PTR hUSKey, DWORD dwIndex, LPSTR pszName, DWORD* pcchName, SHREGENUM_FLAGS enumRegFlags)
#uselib "SHLWAPI.dll"
#cfunc global SHRegEnumUSKeyA "SHRegEnumUSKeyA" intptr, int, var, var, int
; res = SHRegEnumUSKeyA(hUSKey, dwIndex, pszName, pcchName, enumRegFlags)
; hUSKey : INT_PTR -> "intptr"
; dwIndex : DWORD -> "int"
; pszName : LPSTR out -> "var"
; pcchName : DWORD* in/out -> "var"
; enumRegFlags : SHREGENUM_FLAGS -> "int"
; ※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 (
	shlwapi = windows.NewLazySystemDLL("SHLWAPI.dll")
	procSHRegEnumUSKeyA = shlwapi.NewProc("SHRegEnumUSKeyA")
)

// hUSKey (INT_PTR), dwIndex (DWORD), pszName (LPSTR out), pcchName (DWORD* in/out), enumRegFlags (SHREGENUM_FLAGS)
r1, _, err := procSHRegEnumUSKeyA.Call(
	uintptr(hUSKey),
	uintptr(dwIndex),
	uintptr(pszName),
	uintptr(pcchName),
	uintptr(enumRegFlags),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WIN32_ERROR

function SHRegEnumUSKeyA(
  hUSKey: NativeInt;   // INT_PTR
  dwIndex: DWORD;   // DWORD
  pszName: PAnsiChar;   // LPSTR out
  pcchName: Pointer;   // DWORD* in/out
  enumRegFlags: Integer   // SHREGENUM_FLAGS
): DWORD; stdcall;
  external 'SHLWAPI.dll' name 'SHRegEnumUSKeyA';

result := DllCall("SHLWAPI\SHRegEnumUSKeyA"
    , "Ptr", hUSKey   ; INT_PTR
    , "UInt", dwIndex   ; DWORD
    , "Ptr", pszName   ; LPSTR out
    , "Ptr", pcchName   ; DWORD* in/out
    , "Int", enumRegFlags   ; SHREGENUM_FLAGS
    , "UInt")   ; return: WIN32_ERROR

●SHRegEnumUSKeyA(hUSKey, dwIndex, pszName, pcchName, enumRegFlags) = DLL("SHLWAPI.dll", "dword SHRegEnumUSKeyA(int, dword, char*, void*, int)")
# 呼び出し: SHRegEnumUSKeyA(hUSKey, dwIndex, pszName, pcchName, enumRegFlags)
# hUSKey : INT_PTR -> "int"
# dwIndex : DWORD -> "dword"
# pszName : LPSTR out -> "char*"
# pcchName : DWORD* in/out -> "void*"
# enumRegFlags : SHREGENUM_FLAGS -> "int"
# 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)。