RasGetErrorStringA

// RASAPI32.dll  (ANSI / -A)
#include <windows.h>

DWORD RasGetErrorStringA(
    DWORD ResourceId,
    LPSTR lpszString,
    DWORD InBufSize
);

<DllImport("RASAPI32.dll", CharSet:=CharSet.Ansi, ExactSpelling:=True)>
Public Shared Function RasGetErrorStringA(
    ResourceId As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPStr)> lpszString As System.Text.StringBuilder,   ' LPSTR out
    InBufSize As UInteger   ' DWORD
) As UInteger
End Function

' ResourceId : DWORD
' lpszString : LPSTR out
' InBufSize : DWORD
Declare PtrSafe Function RasGetErrorStringA Lib "rasapi32" ( _
    ByVal ResourceId As Long, _
    ByVal lpszString As String, _
    ByVal InBufSize 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

RasGetErrorStringA = ctypes.windll.rasapi32.RasGetErrorStringA
RasGetErrorStringA.restype = wintypes.DWORD
RasGetErrorStringA.argtypes = [
    wintypes.DWORD,  # ResourceId : DWORD
    wintypes.LPSTR,  # lpszString : LPSTR out
    wintypes.DWORD,  # InBufSize : DWORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('RASAPI32.dll')
RasGetErrorStringA = Fiddle::Function.new(
  lib['RasGetErrorStringA'],
  [
    -Fiddle::TYPE_INT,  # ResourceId : DWORD
    Fiddle::TYPE_VOIDP,  # lpszString : LPSTR out
    -Fiddle::TYPE_INT,  # InBufSize : DWORD
  ],
  -Fiddle::TYPE_INT)

#[link(name = "rasapi32")]
extern "system" {
    fn RasGetErrorStringA(
        ResourceId: u32,  // DWORD
        lpszString: *mut u8,  // LPSTR out
        InBufSize: u32  // DWORD
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("RASAPI32.dll", CharSet = CharSet.Ansi)]
public static extern uint RasGetErrorStringA(uint ResourceId, [MarshalAs(UnmanagedType.LPStr)] System.Text.StringBuilder lpszString, uint InBufSize);
"@
$api = Add-Type -MemberDefinition $sig -Name 'RASAPI32_RasGetErrorStringA' -Namespace Win32 -PassThru
# $api::RasGetErrorStringA(ResourceId, lpszString, InBufSize)

#uselib "RASAPI32.dll"
#func global RasGetErrorStringA "RasGetErrorStringA" sptr, sptr, sptr
; RasGetErrorStringA ResourceId, varptr(lpszString), InBufSize   ; 戻り値は stat
; ResourceId : DWORD -> "sptr"
; lpszString : LPSTR out -> "sptr"
; InBufSize : 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 "RASAPI32.dll"
#cfunc global RasGetErrorStringA "RasGetErrorStringA" int, var, int
; res = RasGetErrorStringA(ResourceId, lpszString, InBufSize)
; ResourceId : DWORD -> "int"
; lpszString : LPSTR out -> "var"
; InBufSize : 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。

; DWORD RasGetErrorStringA(DWORD ResourceId, LPSTR lpszString, DWORD InBufSize)
#uselib "RASAPI32.dll"
#cfunc global RasGetErrorStringA "RasGetErrorStringA" int, var, int
; res = RasGetErrorStringA(ResourceId, lpszString, InBufSize)
; ResourceId : DWORD -> "int"
; lpszString : LPSTR out -> "var"
; InBufSize : 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 (
	rasapi32 = windows.NewLazySystemDLL("RASAPI32.dll")
	procRasGetErrorStringA = rasapi32.NewProc("RasGetErrorStringA")
)

// ResourceId (DWORD), lpszString (LPSTR out), InBufSize (DWORD)
r1, _, err := procRasGetErrorStringA.Call(
	uintptr(ResourceId),
	uintptr(lpszString),
	uintptr(InBufSize),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function RasGetErrorStringA(
  ResourceId: DWORD;   // DWORD
  lpszString: PAnsiChar;   // LPSTR out
  InBufSize: DWORD   // DWORD
): DWORD; stdcall;
  external 'RASAPI32.dll' name 'RasGetErrorStringA';

result := DllCall("RASAPI32\RasGetErrorStringA"
    , "UInt", ResourceId   ; DWORD
    , "Ptr", lpszString   ; LPSTR out
    , "UInt", InBufSize   ; DWORD
    , "UInt")   ; return: DWORD

●RasGetErrorStringA(ResourceId, lpszString, InBufSize) = DLL("RASAPI32.dll", "dword RasGetErrorStringA(dword, char*, dword)")
# 呼び出し: RasGetErrorStringA(ResourceId, lpszString, InBufSize)
# ResourceId : DWORD -> "dword"
# lpszString : LPSTR out -> "char*"
# InBufSize : 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)。