DnsGetApplicationSettings

// DNSAPI.dll
#include <windows.h>

DWORD DnsGetApplicationSettings(
    DWORD* pcServers,
    DNS_CUSTOM_SERVER** ppDefaultServers,
    DNS_APPLICATION_SETTINGS* pSettings   // optional
);

<DllImport("DNSAPI.dll", ExactSpelling:=True)>
Public Shared Function DnsGetApplicationSettings(
    <Out> ByRef pcServers As UInteger,   ' DWORD* out
    ppDefaultServers As IntPtr,   ' DNS_CUSTOM_SERVER** out
    pSettings As IntPtr   ' DNS_APPLICATION_SETTINGS* optional, out
) As UInteger
End Function

' pcServers : DWORD* out
' ppDefaultServers : DNS_CUSTOM_SERVER** out
' pSettings : DNS_APPLICATION_SETTINGS* optional, out
Declare PtrSafe Function DnsGetApplicationSettings Lib "dnsapi" ( _
    ByRef pcServers As Long, _
    ByVal ppDefaultServers As LongPtr, _
    ByVal pSettings As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

DnsGetApplicationSettings = ctypes.windll.dnsapi.DnsGetApplicationSettings
DnsGetApplicationSettings.restype = wintypes.DWORD
DnsGetApplicationSettings.argtypes = [
    ctypes.POINTER(wintypes.DWORD),  # pcServers : DWORD* out
    ctypes.c_void_p,  # ppDefaultServers : DNS_CUSTOM_SERVER** out
    ctypes.c_void_p,  # pSettings : DNS_APPLICATION_SETTINGS* optional, out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('DNSAPI.dll')
DnsGetApplicationSettings = Fiddle::Function.new(
  lib['DnsGetApplicationSettings'],
  [
    Fiddle::TYPE_VOIDP,  # pcServers : DWORD* out
    Fiddle::TYPE_VOIDP,  # ppDefaultServers : DNS_CUSTOM_SERVER** out
    Fiddle::TYPE_VOIDP,  # pSettings : DNS_APPLICATION_SETTINGS* optional, out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "dnsapi")]
extern "system" {
    fn DnsGetApplicationSettings(
        pcServers: *mut u32,  // DWORD* out
        ppDefaultServers: *mut *mut DNS_CUSTOM_SERVER,  // DNS_CUSTOM_SERVER** out
        pSettings: *mut DNS_APPLICATION_SETTINGS  // DNS_APPLICATION_SETTINGS* optional, out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("DNSAPI.dll")]
public static extern uint DnsGetApplicationSettings(out uint pcServers, IntPtr ppDefaultServers, IntPtr pSettings);
"@
$api = Add-Type -MemberDefinition $sig -Name 'DNSAPI_DnsGetApplicationSettings' -Namespace Win32 -PassThru
# $api::DnsGetApplicationSettings(pcServers, ppDefaultServers, pSettings)

#uselib "DNSAPI.dll"
#func global DnsGetApplicationSettings "DnsGetApplicationSettings" sptr, sptr, sptr
; DnsGetApplicationSettings varptr(pcServers), varptr(ppDefaultServers), varptr(pSettings)   ; 戻り値は stat
; pcServers : DWORD* out -> "sptr"
; ppDefaultServers : DNS_CUSTOM_SERVER** out -> "sptr"
; pSettings : DNS_APPLICATION_SETTINGS* optional, out -> "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 "DNSAPI.dll"
#cfunc global DnsGetApplicationSettings "DnsGetApplicationSettings" var, var, var
; res = DnsGetApplicationSettings(pcServers, ppDefaultServers, pSettings)
; pcServers : DWORD* out -> "var"
; ppDefaultServers : DNS_CUSTOM_SERVER** out -> "var"
; pSettings : DNS_APPLICATION_SETTINGS* optional, out -> "var"
; ※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。

; DWORD DnsGetApplicationSettings(DWORD* pcServers, DNS_CUSTOM_SERVER** ppDefaultServers, DNS_APPLICATION_SETTINGS* pSettings)
#uselib "DNSAPI.dll"
#cfunc global DnsGetApplicationSettings "DnsGetApplicationSettings" var, var, var
; res = DnsGetApplicationSettings(pcServers, ppDefaultServers, pSettings)
; pcServers : DWORD* out -> "var"
; ppDefaultServers : DNS_CUSTOM_SERVER** out -> "var"
; pSettings : DNS_APPLICATION_SETTINGS* optional, out -> "var"
; ※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 (
	dnsapi = windows.NewLazySystemDLL("DNSAPI.dll")
	procDnsGetApplicationSettings = dnsapi.NewProc("DnsGetApplicationSettings")
)

// pcServers (DWORD* out), ppDefaultServers (DNS_CUSTOM_SERVER** out), pSettings (DNS_APPLICATION_SETTINGS* optional, out)
r1, _, err := procDnsGetApplicationSettings.Call(
	uintptr(pcServers),
	uintptr(ppDefaultServers),
	uintptr(pSettings),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function DnsGetApplicationSettings(
  pcServers: Pointer;   // DWORD* out
  ppDefaultServers: Pointer;   // DNS_CUSTOM_SERVER** out
  pSettings: Pointer   // DNS_APPLICATION_SETTINGS* optional, out
): DWORD; stdcall;
  external 'DNSAPI.dll' name 'DnsGetApplicationSettings';

result := DllCall("DNSAPI\DnsGetApplicationSettings"
    , "Ptr", pcServers   ; DWORD* out
    , "Ptr", ppDefaultServers   ; DNS_CUSTOM_SERVER** out
    , "Ptr", pSettings   ; DNS_APPLICATION_SETTINGS* optional, out
    , "UInt")   ; return: DWORD

●DnsGetApplicationSettings(pcServers, ppDefaultServers, pSettings) = DLL("DNSAPI.dll", "dword DnsGetApplicationSettings(void*, void*, void*)")
# 呼び出し: DnsGetApplicationSettings(pcServers, ppDefaultServers, pSettings)
# pcServers : DWORD* out -> "void*"
# ppDefaultServers : DNS_CUSTOM_SERVER** out -> "void*"
# pSettings : DNS_APPLICATION_SETTINGS* optional, out -> "void*"
# 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)。