UrlCombineA

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

HRESULT UrlCombineA(
    LPCSTR pszBase,
    LPCSTR pszRelative,
    LPSTR pszCombined,   // optional
    DWORD* pcchCombined,
    DWORD dwFlags
);

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function UrlCombineA(
    <MarshalAs(UnmanagedType.LPStr)> pszBase As String,   ' LPCSTR
    <MarshalAs(UnmanagedType.LPStr)> pszRelative As String,   ' LPCSTR
    <MarshalAs(UnmanagedType.LPStr)> pszCombined As System.Text.StringBuilder,   ' LPSTR optional, out
    ByRef pcchCombined As UInteger,   ' DWORD* in/out
    dwFlags As UInteger   ' DWORD
) As Integer
End Function

' pszBase : LPCSTR
' pszRelative : LPCSTR
' pszCombined : LPSTR optional, out
' pcchCombined : DWORD* in/out
' dwFlags : DWORD
Declare PtrSafe Function UrlCombineA Lib "shlwapi" ( _
    ByVal pszBase As String, _
    ByVal pszRelative As String, _
    ByVal pszCombined As String, _
    ByRef pcchCombined As Long, _
    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

UrlCombineA = ctypes.windll.shlwapi.UrlCombineA
UrlCombineA.restype = ctypes.c_int
UrlCombineA.argtypes = [
    wintypes.LPCSTR,  # pszBase : LPCSTR
    wintypes.LPCSTR,  # pszRelative : LPCSTR
    wintypes.LPSTR,  # pszCombined : LPSTR optional, out
    ctypes.POINTER(wintypes.DWORD),  # pcchCombined : DWORD* in/out
    wintypes.DWORD,  # dwFlags : DWORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHLWAPI.dll')
UrlCombineA = Fiddle::Function.new(
  lib['UrlCombineA'],
  [
    Fiddle::TYPE_VOIDP,  # pszBase : LPCSTR
    Fiddle::TYPE_VOIDP,  # pszRelative : LPCSTR
    Fiddle::TYPE_VOIDP,  # pszCombined : LPSTR optional, out
    Fiddle::TYPE_VOIDP,  # pcchCombined : DWORD* in/out
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
  ],
  Fiddle::TYPE_INT)

#[link(name = "shlwapi")]
extern "system" {
    fn UrlCombineA(
        pszBase: *const u8,  // LPCSTR
        pszRelative: *const u8,  // LPCSTR
        pszCombined: *mut u8,  // LPSTR optional, out
        pcchCombined: *mut u32,  // DWORD* in/out
        dwFlags: u32  // DWORD
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHLWAPI.dll", CharSet = CharSet.Ansi)]
public static extern int UrlCombineA([MarshalAs(UnmanagedType.LPStr)] string pszBase, [MarshalAs(UnmanagedType.LPStr)] string pszRelative, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder pszCombined, ref uint pcchCombined, uint dwFlags);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_UrlCombineA' -Namespace Win32 -PassThru
# $api::UrlCombineA(pszBase, pszRelative, pszCombined, pcchCombined, dwFlags)

#uselib "SHLWAPI.dll"
#func global UrlCombineA "UrlCombineA" sptr, sptr, sptr, sptr, sptr
; UrlCombineA pszBase, pszRelative, varptr(pszCombined), varptr(pcchCombined), dwFlags   ; 戻り値は stat
; pszBase : LPCSTR -> "sptr"
; pszRelative : LPCSTR -> "sptr"
; pszCombined : LPSTR optional, out -> "sptr"
; pcchCombined : DWORD* in/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 UrlCombineA "UrlCombineA" str, str, var, var, int
; res = UrlCombineA(pszBase, pszRelative, pszCombined, pcchCombined, dwFlags)
; pszBase : LPCSTR -> "str"
; pszRelative : LPCSTR -> "str"
; pszCombined : LPSTR optional, out -> "var"
; pcchCombined : DWORD* in/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。

; HRESULT UrlCombineA(LPCSTR pszBase, LPCSTR pszRelative, LPSTR pszCombined, DWORD* pcchCombined, DWORD dwFlags)
#uselib "SHLWAPI.dll"
#cfunc global UrlCombineA "UrlCombineA" str, str, var, var, int
; res = UrlCombineA(pszBase, pszRelative, pszCombined, pcchCombined, dwFlags)
; pszBase : LPCSTR -> "str"
; pszRelative : LPCSTR -> "str"
; pszCombined : LPSTR optional, out -> "var"
; pcchCombined : DWORD* in/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")
	procUrlCombineA = shlwapi.NewProc("UrlCombineA")
)

// pszBase (LPCSTR), pszRelative (LPCSTR), pszCombined (LPSTR optional, out), pcchCombined (DWORD* in/out), dwFlags (DWORD)
r1, _, err := procUrlCombineA.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(pszBase))),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(pszRelative))),
	uintptr(pszCombined),
	uintptr(pcchCombined),
	uintptr(dwFlags),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function UrlCombineA(
  pszBase: PAnsiChar;   // LPCSTR
  pszRelative: PAnsiChar;   // LPCSTR
  pszCombined: PAnsiChar;   // LPSTR optional, out
  pcchCombined: Pointer;   // DWORD* in/out
  dwFlags: DWORD   // DWORD
): Integer; stdcall;
  external 'SHLWAPI.dll' name 'UrlCombineA';

result := DllCall("SHLWAPI\UrlCombineA"
    , "AStr", pszBase   ; LPCSTR
    , "AStr", pszRelative   ; LPCSTR
    , "Ptr", pszCombined   ; LPSTR optional, out
    , "Ptr", pcchCombined   ; DWORD* in/out
    , "UInt", dwFlags   ; DWORD
    , "Int")   ; return: HRESULT

●UrlCombineA(pszBase, pszRelative, pszCombined, pcchCombined, dwFlags) = DLL("SHLWAPI.dll", "int UrlCombineA(char*, char*, char*, void*, dword)")
# 呼び出し: UrlCombineA(pszBase, pszRelative, pszCombined, pcchCombined, dwFlags)
# pszBase : LPCSTR -> "char*"
# pszRelative : LPCSTR -> "char*"
# pszCombined : LPSTR optional, out -> "char*"
# pcchCombined : DWORD* in/out -> "void*"
# 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)。