InternetOpenA

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

void* InternetOpenA(
    LPCSTR lpszAgent,   // optional
    DWORD dwAccessType,
    LPCSTR lpszProxy,   // optional
    LPCSTR lpszProxyBypass,   // optional
    DWORD dwFlags
);

<DllImport("WININET.dll", CharSet:=CharSet.Ansi, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function InternetOpenA(
    <MarshalAs(UnmanagedType.LPStr)> lpszAgent As String,   ' LPCSTR optional
    dwAccessType As UInteger,   ' DWORD
    <MarshalAs(UnmanagedType.LPStr)> lpszProxy As String,   ' LPCSTR optional
    <MarshalAs(UnmanagedType.LPStr)> lpszProxyBypass As String,   ' LPCSTR optional
    dwFlags As UInteger   ' DWORD
) As IntPtr
End Function

' lpszAgent : LPCSTR optional
' dwAccessType : DWORD
' lpszProxy : LPCSTR optional
' lpszProxyBypass : LPCSTR optional
' dwFlags : DWORD
Declare PtrSafe Function InternetOpenA Lib "wininet" ( _
    ByVal lpszAgent As String, _
    ByVal dwAccessType As Long, _
    ByVal lpszProxy As String, _
    ByVal lpszProxyBypass As String, _
    ByVal dwFlags As Long) As LongPtr
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

InternetOpenA = ctypes.windll.wininet.InternetOpenA
InternetOpenA.restype = ctypes.c_void_p
InternetOpenA.argtypes = [
    wintypes.LPCSTR,  # lpszAgent : LPCSTR optional
    wintypes.DWORD,  # dwAccessType : DWORD
    wintypes.LPCSTR,  # lpszProxy : LPCSTR optional
    wintypes.LPCSTR,  # lpszProxyBypass : LPCSTR optional
    wintypes.DWORD,  # dwFlags : DWORD
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('WININET.dll')
InternetOpenA = Fiddle::Function.new(
  lib['InternetOpenA'],
  [
    Fiddle::TYPE_VOIDP,  # lpszAgent : LPCSTR optional
    -Fiddle::TYPE_INT,  # dwAccessType : DWORD
    Fiddle::TYPE_VOIDP,  # lpszProxy : LPCSTR optional
    Fiddle::TYPE_VOIDP,  # lpszProxyBypass : LPCSTR optional
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
  ],
  Fiddle::TYPE_VOIDP)

#[link(name = "wininet")]
extern "system" {
    fn InternetOpenA(
        lpszAgent: *const u8,  // LPCSTR optional
        dwAccessType: u32,  // DWORD
        lpszProxy: *const u8,  // LPCSTR optional
        lpszProxyBypass: *const u8,  // LPCSTR optional
        dwFlags: u32  // DWORD
    ) -> *mut ();
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("WININET.dll", CharSet = CharSet.Ansi, SetLastError = true)]
public static extern IntPtr InternetOpenA([MarshalAs(UnmanagedType.LPStr)] string lpszAgent, uint dwAccessType, [MarshalAs(UnmanagedType.LPStr)] string lpszProxy, [MarshalAs(UnmanagedType.LPStr)] string lpszProxyBypass, uint dwFlags);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WININET_InternetOpenA' -Namespace Win32 -PassThru
# $api::InternetOpenA(lpszAgent, dwAccessType, lpszProxy, lpszProxyBypass, dwFlags)

#uselib "WININET.dll"
#func global InternetOpenA "InternetOpenA" sptr, sptr, sptr, sptr, sptr
; InternetOpenA lpszAgent, dwAccessType, lpszProxy, lpszProxyBypass, dwFlags   ; 戻り値は stat
; lpszAgent : LPCSTR optional -> "sptr"
; dwAccessType : DWORD -> "sptr"
; lpszProxy : LPCSTR optional -> "sptr"
; lpszProxyBypass : LPCSTR optional -> "sptr"
; dwFlags : 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 InternetOpenA "InternetOpenA" str, int, str, str, int
; res = InternetOpenA(lpszAgent, dwAccessType, lpszProxy, lpszProxyBypass, dwFlags)
; lpszAgent : LPCSTR optional -> "str"
; dwAccessType : DWORD -> "int"
; lpszProxy : LPCSTR optional -> "str"
; lpszProxyBypass : LPCSTR optional -> "str"
; dwFlags : DWORD -> "int"

; void* InternetOpenA(LPCSTR lpszAgent, DWORD dwAccessType, LPCSTR lpszProxy, LPCSTR lpszProxyBypass, DWORD dwFlags)
#uselib "WININET.dll"
#cfunc global InternetOpenA "InternetOpenA" str, int, str, str, int
; res = InternetOpenA(lpszAgent, dwAccessType, lpszProxy, lpszProxyBypass, dwFlags)
; lpszAgent : LPCSTR optional -> "str"
; dwAccessType : DWORD -> "int"
; lpszProxy : LPCSTR optional -> "str"
; lpszProxyBypass : LPCSTR optional -> "str"
; dwFlags : DWORD -> "int"

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

var (
	wininet = windows.NewLazySystemDLL("WININET.dll")
	procInternetOpenA = wininet.NewProc("InternetOpenA")
)

// lpszAgent (LPCSTR optional), dwAccessType (DWORD), lpszProxy (LPCSTR optional), lpszProxyBypass (LPCSTR optional), dwFlags (DWORD)
r1, _, err := procInternetOpenA.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(lpszAgent))),
	uintptr(dwAccessType),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(lpszProxy))),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(lpszProxyBypass))),
	uintptr(dwFlags),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // void*

function InternetOpenA(
  lpszAgent: PAnsiChar;   // LPCSTR optional
  dwAccessType: DWORD;   // DWORD
  lpszProxy: PAnsiChar;   // LPCSTR optional
  lpszProxyBypass: PAnsiChar;   // LPCSTR optional
  dwFlags: DWORD   // DWORD
): Pointer; stdcall;
  external 'WININET.dll' name 'InternetOpenA';

result := DllCall("WININET\InternetOpenA"
    , "AStr", lpszAgent   ; LPCSTR optional
    , "UInt", dwAccessType   ; DWORD
    , "AStr", lpszProxy   ; LPCSTR optional
    , "AStr", lpszProxyBypass   ; LPCSTR optional
    , "UInt", dwFlags   ; DWORD
    , "Ptr")   ; return: void*

●InternetOpenA(lpszAgent, dwAccessType, lpszProxy, lpszProxyBypass, dwFlags) = DLL("WININET.dll", "void* InternetOpenA(char*, dword, char*, char*, dword)")
# 呼び出し: InternetOpenA(lpszAgent, dwAccessType, lpszProxy, lpszProxyBypass, dwFlags)
# lpszAgent : LPCSTR optional -> "char*"
# dwAccessType : DWORD -> "dword"
# lpszProxy : LPCSTR optional -> "char*"
# lpszProxyBypass : LPCSTR optional -> "char*"
# dwFlags : 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)。