SHRegGetPathA

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

WIN32_ERROR SHRegGetPathA(
    HKEY hKey,
    LPCSTR pcszSubKey,   // optional
    LPCSTR pcszValue,   // optional
    LPSTR pszPath,
    DWORD dwFlags
);

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function SHRegGetPathA(
    hKey As IntPtr,   ' HKEY
    <MarshalAs(UnmanagedType.LPStr)> pcszSubKey As String,   ' LPCSTR optional
    <MarshalAs(UnmanagedType.LPStr)> pcszValue As String,   ' LPCSTR optional
    <MarshalAs(UnmanagedType.LPStr)> pszPath As System.Text.StringBuilder,   ' LPSTR out
    dwFlags As UInteger   ' DWORD
) As UInteger
End Function

' hKey : HKEY
' pcszSubKey : LPCSTR optional
' pcszValue : LPCSTR optional
' pszPath : LPSTR out
' dwFlags : DWORD
Declare PtrSafe Function SHRegGetPathA Lib "shlwapi" ( _
    ByVal hKey As LongPtr, _
    ByVal pcszSubKey As String, _
    ByVal pcszValue As String, _
    ByVal pszPath As String, _
    ByVal dwFlags 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

SHRegGetPathA = ctypes.windll.shlwapi.SHRegGetPathA
SHRegGetPathA.restype = wintypes.DWORD
SHRegGetPathA.argtypes = [
    wintypes.HANDLE,  # hKey : HKEY
    wintypes.LPCSTR,  # pcszSubKey : LPCSTR optional
    wintypes.LPCSTR,  # pcszValue : LPCSTR optional
    wintypes.LPSTR,  # pszPath : LPSTR out
    wintypes.DWORD,  # dwFlags : DWORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHLWAPI.dll')
SHRegGetPathA = Fiddle::Function.new(
  lib['SHRegGetPathA'],
  [
    Fiddle::TYPE_VOIDP,  # hKey : HKEY
    Fiddle::TYPE_VOIDP,  # pcszSubKey : LPCSTR optional
    Fiddle::TYPE_VOIDP,  # pcszValue : LPCSTR optional
    Fiddle::TYPE_VOIDP,  # pszPath : LPSTR out
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
  ],
  -Fiddle::TYPE_INT)

#[link(name = "shlwapi")]
extern "system" {
    fn SHRegGetPathA(
        hKey: *mut core::ffi::c_void,  // HKEY
        pcszSubKey: *const u8,  // LPCSTR optional
        pcszValue: *const u8,  // LPCSTR optional
        pszPath: *mut u8,  // LPSTR out
        dwFlags: u32  // DWORD
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHLWAPI.dll", CharSet = CharSet.Ansi)]
public static extern uint SHRegGetPathA(IntPtr hKey, [MarshalAs(UnmanagedType.LPStr)] string pcszSubKey, [MarshalAs(UnmanagedType.LPStr)] string pcszValue, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder pszPath, uint dwFlags);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_SHRegGetPathA' -Namespace Win32 -PassThru
# $api::SHRegGetPathA(hKey, pcszSubKey, pcszValue, pszPath, dwFlags)

#uselib "SHLWAPI.dll"
#func global SHRegGetPathA "SHRegGetPathA" sptr, sptr, sptr, sptr, sptr
; SHRegGetPathA hKey, pcszSubKey, pcszValue, varptr(pszPath), dwFlags   ; 戻り値は stat
; hKey : HKEY -> "sptr"
; pcszSubKey : LPCSTR optional -> "sptr"
; pcszValue : LPCSTR optional -> "sptr"
; pszPath : LPSTR out -> "sptr"
; dwFlags : 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 "SHLWAPI.dll"
#cfunc global SHRegGetPathA "SHRegGetPathA" sptr, str, str, var, int
; res = SHRegGetPathA(hKey, pcszSubKey, pcszValue, pszPath, dwFlags)
; hKey : HKEY -> "sptr"
; pcszSubKey : LPCSTR optional -> "str"
; pcszValue : LPCSTR optional -> "str"
; pszPath : LPSTR out -> "var"
; dwFlags : DWORD -> "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 SHRegGetPathA(HKEY hKey, LPCSTR pcszSubKey, LPCSTR pcszValue, LPSTR pszPath, DWORD dwFlags)
#uselib "SHLWAPI.dll"
#cfunc global SHRegGetPathA "SHRegGetPathA" intptr, str, str, var, int
; res = SHRegGetPathA(hKey, pcszSubKey, pcszValue, pszPath, dwFlags)
; hKey : HKEY -> "intptr"
; pcszSubKey : LPCSTR optional -> "str"
; pcszValue : LPCSTR optional -> "str"
; pszPath : LPSTR out -> "var"
; dwFlags : DWORD -> "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")
	procSHRegGetPathA = shlwapi.NewProc("SHRegGetPathA")
)

// hKey (HKEY), pcszSubKey (LPCSTR optional), pcszValue (LPCSTR optional), pszPath (LPSTR out), dwFlags (DWORD)
r1, _, err := procSHRegGetPathA.Call(
	uintptr(hKey),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(pcszSubKey))),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(pcszValue))),
	uintptr(pszPath),
	uintptr(dwFlags),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WIN32_ERROR

function SHRegGetPathA(
  hKey: THandle;   // HKEY
  pcszSubKey: PAnsiChar;   // LPCSTR optional
  pcszValue: PAnsiChar;   // LPCSTR optional
  pszPath: PAnsiChar;   // LPSTR out
  dwFlags: DWORD   // DWORD
): DWORD; stdcall;
  external 'SHLWAPI.dll' name 'SHRegGetPathA';

result := DllCall("SHLWAPI\SHRegGetPathA"
    , "Ptr", hKey   ; HKEY
    , "AStr", pcszSubKey   ; LPCSTR optional
    , "AStr", pcszValue   ; LPCSTR optional
    , "Ptr", pszPath   ; LPSTR out
    , "UInt", dwFlags   ; DWORD
    , "UInt")   ; return: WIN32_ERROR

●SHRegGetPathA(hKey, pcszSubKey, pcszValue, pszPath, dwFlags) = DLL("SHLWAPI.dll", "dword SHRegGetPathA(void*, char*, char*, char*, dword)")
# 呼び出し: SHRegGetPathA(hKey, pcszSubKey, pcszValue, pszPath, dwFlags)
# hKey : HKEY -> "void*"
# pcszSubKey : LPCSTR optional -> "char*"
# pcszValue : LPCSTR optional -> "char*"
# pszPath : LPSTR out -> "char*"
# dwFlags : 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)。