InternetSetOptionA

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

BOOL InternetSetOptionA(
    void* hInternet,   // optional
    DWORD dwOption,
    void* lpBuffer,   // optional
    DWORD dwBufferLength
);

<DllImport("WININET.dll", CharSet:=CharSet.Ansi, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function InternetSetOptionA(
    hInternet As IntPtr,   ' void* optional
    dwOption As UInteger,   ' DWORD
    lpBuffer As IntPtr,   ' void* optional
    dwBufferLength As UInteger   ' DWORD
) As Boolean
End Function

' hInternet : void* optional
' dwOption : DWORD
' lpBuffer : void* optional
' dwBufferLength : DWORD
Declare PtrSafe Function InternetSetOptionA Lib "wininet" ( _
    ByVal hInternet As LongPtr, _
    ByVal dwOption As Long, _
    ByVal lpBuffer As LongPtr, _
    ByVal dwBufferLength 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

InternetSetOptionA = ctypes.windll.wininet.InternetSetOptionA
InternetSetOptionA.restype = wintypes.BOOL
InternetSetOptionA.argtypes = [
    ctypes.POINTER(None),  # hInternet : void* optional
    wintypes.DWORD,  # dwOption : DWORD
    ctypes.POINTER(None),  # lpBuffer : void* optional
    wintypes.DWORD,  # dwBufferLength : DWORD
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('WININET.dll')
InternetSetOptionA = Fiddle::Function.new(
  lib['InternetSetOptionA'],
  [
    Fiddle::TYPE_VOIDP,  # hInternet : void* optional
    -Fiddle::TYPE_INT,  # dwOption : DWORD
    Fiddle::TYPE_VOIDP,  # lpBuffer : void* optional
    -Fiddle::TYPE_INT,  # dwBufferLength : DWORD
  ],
  Fiddle::TYPE_INT)

#[link(name = "wininet")]
extern "system" {
    fn InternetSetOptionA(
        hInternet: *mut (),  // void* optional
        dwOption: u32,  // DWORD
        lpBuffer: *mut (),  // void* optional
        dwBufferLength: u32  // DWORD
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("WININET.dll", CharSet = CharSet.Ansi, SetLastError = true)]
public static extern bool InternetSetOptionA(IntPtr hInternet, uint dwOption, IntPtr lpBuffer, uint dwBufferLength);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WININET_InternetSetOptionA' -Namespace Win32 -PassThru
# $api::InternetSetOptionA(hInternet, dwOption, lpBuffer, dwBufferLength)

#uselib "WININET.dll"
#func global InternetSetOptionA "InternetSetOptionA" sptr, sptr, sptr, sptr
; InternetSetOptionA hInternet, dwOption, lpBuffer, dwBufferLength   ; 戻り値は stat
; hInternet : void* optional -> "sptr"
; dwOption : DWORD -> "sptr"
; lpBuffer : void* optional -> "sptr"
; dwBufferLength : 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 "WININET.dll"
#cfunc global InternetSetOptionA "InternetSetOptionA" sptr, int, sptr, int
; res = InternetSetOptionA(hInternet, dwOption, lpBuffer, dwBufferLength)
; hInternet : void* optional -> "sptr"
; dwOption : DWORD -> "int"
; lpBuffer : void* optional -> "sptr"
; dwBufferLength : DWORD -> "int"

; BOOL InternetSetOptionA(void* hInternet, DWORD dwOption, void* lpBuffer, DWORD dwBufferLength)
#uselib "WININET.dll"
#cfunc global InternetSetOptionA "InternetSetOptionA" intptr, int, intptr, int
; res = InternetSetOptionA(hInternet, dwOption, lpBuffer, dwBufferLength)
; hInternet : void* optional -> "intptr"
; dwOption : DWORD -> "int"
; lpBuffer : void* optional -> "intptr"
; dwBufferLength : DWORD -> "int"

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

var (
	wininet = windows.NewLazySystemDLL("WININET.dll")
	procInternetSetOptionA = wininet.NewProc("InternetSetOptionA")
)

// hInternet (void* optional), dwOption (DWORD), lpBuffer (void* optional), dwBufferLength (DWORD)
r1, _, err := procInternetSetOptionA.Call(
	uintptr(hInternet),
	uintptr(dwOption),
	uintptr(lpBuffer),
	uintptr(dwBufferLength),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function InternetSetOptionA(
  hInternet: Pointer;   // void* optional
  dwOption: DWORD;   // DWORD
  lpBuffer: Pointer;   // void* optional
  dwBufferLength: DWORD   // DWORD
): BOOL; stdcall;
  external 'WININET.dll' name 'InternetSetOptionA';

result := DllCall("WININET\InternetSetOptionA"
    , "Ptr", hInternet   ; void* optional
    , "UInt", dwOption   ; DWORD
    , "Ptr", lpBuffer   ; void* optional
    , "UInt", dwBufferLength   ; DWORD
    , "Int")   ; return: BOOL

●InternetSetOptionA(hInternet, dwOption, lpBuffer, dwBufferLength) = DLL("WININET.dll", "bool InternetSetOptionA(void*, dword, void*, dword)")
# 呼び出し: InternetSetOptionA(hInternet, dwOption, lpBuffer, dwBufferLength)
# hInternet : void* optional -> "void*"
# dwOption : DWORD -> "dword"
# lpBuffer : void* optional -> "void*"
# dwBufferLength : 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)。