SHGetSpecialFolderPathA

// SHELL32.dll  (ANSI / -A)
#include <windows.h>

BOOL SHGetSpecialFolderPathA(
    HWND hwnd,   // optional
    LPSTR pszPath,
    INT csidl,
    BOOL fCreate
);

<DllImport("SHELL32.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function SHGetSpecialFolderPathA(
    hwnd As IntPtr,   ' HWND optional
    <MarshalAs(UnmanagedType.LPStr)> pszPath As System.Text.StringBuilder,   ' LPSTR out
    csidl As Integer,   ' INT
    fCreate As Boolean   ' BOOL
) As Boolean
End Function

' hwnd : HWND optional
' pszPath : LPSTR out
' csidl : INT
' fCreate : BOOL
Declare PtrSafe Function SHGetSpecialFolderPathA Lib "shell32" ( _
    ByVal hwnd As LongPtr, _
    ByVal pszPath As String, _
    ByVal csidl As Long, _
    ByVal fCreate 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

SHGetSpecialFolderPathA = ctypes.windll.shell32.SHGetSpecialFolderPathA
SHGetSpecialFolderPathA.restype = wintypes.BOOL
SHGetSpecialFolderPathA.argtypes = [
    wintypes.HANDLE,  # hwnd : HWND optional
    wintypes.LPSTR,  # pszPath : LPSTR out
    ctypes.c_int,  # csidl : INT
    wintypes.BOOL,  # fCreate : BOOL
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHELL32.dll')
SHGetSpecialFolderPathA = Fiddle::Function.new(
  lib['SHGetSpecialFolderPathA'],
  [
    Fiddle::TYPE_VOIDP,  # hwnd : HWND optional
    Fiddle::TYPE_VOIDP,  # pszPath : LPSTR out
    Fiddle::TYPE_INT,  # csidl : INT
    Fiddle::TYPE_INT,  # fCreate : BOOL
  ],
  Fiddle::TYPE_INT)

#[link(name = "shell32")]
extern "system" {
    fn SHGetSpecialFolderPathA(
        hwnd: *mut core::ffi::c_void,  // HWND optional
        pszPath: *mut u8,  // LPSTR out
        csidl: i32,  // INT
        fCreate: i32  // BOOL
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("SHELL32.dll", CharSet = CharSet.Ansi)]
public static extern bool SHGetSpecialFolderPathA(IntPtr hwnd, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder pszPath, int csidl, bool fCreate);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHELL32_SHGetSpecialFolderPathA' -Namespace Win32 -PassThru
# $api::SHGetSpecialFolderPathA(hwnd, pszPath, csidl, fCreate)

#uselib "SHELL32.dll"
#func global SHGetSpecialFolderPathA "SHGetSpecialFolderPathA" sptr, sptr, sptr, sptr
; SHGetSpecialFolderPathA hwnd, varptr(pszPath), csidl, fCreate   ; 戻り値は stat
; hwnd : HWND optional -> "sptr"
; pszPath : LPSTR out -> "sptr"
; csidl : INT -> "sptr"
; fCreate : BOOL -> "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 "SHELL32.dll"
#cfunc global SHGetSpecialFolderPathA "SHGetSpecialFolderPathA" sptr, var, int, int
; res = SHGetSpecialFolderPathA(hwnd, pszPath, csidl, fCreate)
; hwnd : HWND optional -> "sptr"
; pszPath : LPSTR out -> "var"
; csidl : INT -> "int"
; fCreate : BOOL -> "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。

; BOOL SHGetSpecialFolderPathA(HWND hwnd, LPSTR pszPath, INT csidl, BOOL fCreate)
#uselib "SHELL32.dll"
#cfunc global SHGetSpecialFolderPathA "SHGetSpecialFolderPathA" intptr, var, int, int
; res = SHGetSpecialFolderPathA(hwnd, pszPath, csidl, fCreate)
; hwnd : HWND optional -> "intptr"
; pszPath : LPSTR out -> "var"
; csidl : INT -> "int"
; fCreate : BOOL -> "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 (
	shell32 = windows.NewLazySystemDLL("SHELL32.dll")
	procSHGetSpecialFolderPathA = shell32.NewProc("SHGetSpecialFolderPathA")
)

// hwnd (HWND optional), pszPath (LPSTR out), csidl (INT), fCreate (BOOL)
r1, _, err := procSHGetSpecialFolderPathA.Call(
	uintptr(hwnd),
	uintptr(pszPath),
	uintptr(csidl),
	uintptr(fCreate),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function SHGetSpecialFolderPathA(
  hwnd: THandle;   // HWND optional
  pszPath: PAnsiChar;   // LPSTR out
  csidl: Integer;   // INT
  fCreate: BOOL   // BOOL
): BOOL; stdcall;
  external 'SHELL32.dll' name 'SHGetSpecialFolderPathA';

result := DllCall("SHELL32\SHGetSpecialFolderPathA"
    , "Ptr", hwnd   ; HWND optional
    , "Ptr", pszPath   ; LPSTR out
    , "Int", csidl   ; INT
    , "Int", fCreate   ; BOOL
    , "Int")   ; return: BOOL

●SHGetSpecialFolderPathA(hwnd, pszPath, csidl, fCreate) = DLL("SHELL32.dll", "bool SHGetSpecialFolderPathA(void*, char*, int, bool)")
# 呼び出し: SHGetSpecialFolderPathA(hwnd, pszPath, csidl, fCreate)
# hwnd : HWND optional -> "void*"
# pszPath : LPSTR out -> "char*"
# csidl : INT -> "int"
# fCreate : BOOL -> "bool"
# 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)。