SHSetFolderPathA

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

HRESULT SHSetFolderPathA(
    INT csidl,
    HANDLE hToken,   // optional
    DWORD dwFlags,
    LPCSTR pszPath
);

<DllImport("SHELL32.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function SHSetFolderPathA(
    csidl As Integer,   ' INT
    hToken As IntPtr,   ' HANDLE optional
    dwFlags As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPStr)> pszPath As String   ' LPCSTR
) As Integer
End Function

' csidl : INT
' hToken : HANDLE optional
' dwFlags : DWORD
' pszPath : LPCSTR
Declare PtrSafe Function SHSetFolderPathA Lib "shell32" ( _
    ByVal csidl As Long, _
    ByVal hToken As LongPtr, _
    ByVal dwFlags As Long, _
    ByVal pszPath 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

SHSetFolderPathA = ctypes.windll.shell32.SHSetFolderPathA
SHSetFolderPathA.restype = ctypes.c_int
SHSetFolderPathA.argtypes = [
    ctypes.c_int,  # csidl : INT
    wintypes.HANDLE,  # hToken : HANDLE optional
    wintypes.DWORD,  # dwFlags : DWORD
    wintypes.LPCSTR,  # pszPath : LPCSTR
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHELL32.dll')
SHSetFolderPathA = Fiddle::Function.new(
  lib['SHSetFolderPathA'],
  [
    Fiddle::TYPE_INT,  # csidl : INT
    Fiddle::TYPE_VOIDP,  # hToken : HANDLE optional
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_VOIDP,  # pszPath : LPCSTR
  ],
  Fiddle::TYPE_INT)

#[link(name = "shell32")]
extern "system" {
    fn SHSetFolderPathA(
        csidl: i32,  // INT
        hToken: *mut core::ffi::c_void,  // HANDLE optional
        dwFlags: u32,  // DWORD
        pszPath: *const u8  // LPCSTR
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHELL32.dll", CharSet = CharSet.Ansi)]
public static extern int SHSetFolderPathA(int csidl, IntPtr hToken, uint dwFlags, [MarshalAs(UnmanagedType.LPStr)] string pszPath);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHELL32_SHSetFolderPathA' -Namespace Win32 -PassThru
# $api::SHSetFolderPathA(csidl, hToken, dwFlags, pszPath)

#uselib "SHELL32.dll"
#func global SHSetFolderPathA "SHSetFolderPathA" sptr, sptr, sptr, sptr
; SHSetFolderPathA csidl, hToken, dwFlags, pszPath   ; 戻り値は stat
; csidl : INT -> "sptr"
; hToken : HANDLE optional -> "sptr"
; dwFlags : DWORD -> "sptr"
; pszPath : LPCSTR -> "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 SHSetFolderPathA "SHSetFolderPathA" int, sptr, int, str
; res = SHSetFolderPathA(csidl, hToken, dwFlags, pszPath)
; csidl : INT -> "int"
; hToken : HANDLE optional -> "sptr"
; dwFlags : DWORD -> "int"
; pszPath : LPCSTR -> "str"

; HRESULT SHSetFolderPathA(INT csidl, HANDLE hToken, DWORD dwFlags, LPCSTR pszPath)
#uselib "SHELL32.dll"
#cfunc global SHSetFolderPathA "SHSetFolderPathA" int, intptr, int, str
; res = SHSetFolderPathA(csidl, hToken, dwFlags, pszPath)
; csidl : INT -> "int"
; hToken : HANDLE optional -> "intptr"
; dwFlags : DWORD -> "int"
; pszPath : LPCSTR -> "str"

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	shell32 = windows.NewLazySystemDLL("SHELL32.dll")
	procSHSetFolderPathA = shell32.NewProc("SHSetFolderPathA")
)

// csidl (INT), hToken (HANDLE optional), dwFlags (DWORD), pszPath (LPCSTR)
r1, _, err := procSHSetFolderPathA.Call(
	uintptr(csidl),
	uintptr(hToken),
	uintptr(dwFlags),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(pszPath))),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function SHSetFolderPathA(
  csidl: Integer;   // INT
  hToken: THandle;   // HANDLE optional
  dwFlags: DWORD;   // DWORD
  pszPath: PAnsiChar   // LPCSTR
): Integer; stdcall;
  external 'SHELL32.dll' name 'SHSetFolderPathA';

result := DllCall("SHELL32\SHSetFolderPathA"
    , "Int", csidl   ; INT
    , "Ptr", hToken   ; HANDLE optional
    , "UInt", dwFlags   ; DWORD
    , "AStr", pszPath   ; LPCSTR
    , "Int")   ; return: HRESULT

●SHSetFolderPathA(csidl, hToken, dwFlags, pszPath) = DLL("SHELL32.dll", "int SHSetFolderPathA(int, void*, dword, char*)")
# 呼び出し: SHSetFolderPathA(csidl, hToken, dwFlags, pszPath)
# csidl : INT -> "int"
# hToken : HANDLE optional -> "void*"
# dwFlags : DWORD -> "dword"
# pszPath : LPCSTR -> "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)。