GetDiskInfoA

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

BOOL GetDiskInfoA(
    LPCSTR pszPath,
    DWORD* pdwClusterSize,   // optional
    ULONGLONG* pdlAvail,   // optional
    ULONGLONG* pdlTotal   // optional
);

<DllImport("WININET.dll", ExactSpelling:=True)>
Public Shared Function GetDiskInfoA(
    <MarshalAs(UnmanagedType.LPStr)> pszPath As String,   ' LPCSTR
    pdwClusterSize As IntPtr,   ' DWORD* optional, out
    pdlAvail As IntPtr,   ' ULONGLONG* optional, out
    pdlTotal As IntPtr   ' ULONGLONG* optional, out
) As Boolean
End Function

' pszPath : LPCSTR
' pdwClusterSize : DWORD* optional, out
' pdlAvail : ULONGLONG* optional, out
' pdlTotal : ULONGLONG* optional, out
Declare PtrSafe Function GetDiskInfoA Lib "wininet" ( _
    ByVal pszPath As String, _
    ByVal pdwClusterSize As LongPtr, _
    ByVal pdlAvail As LongPtr, _
    ByVal pdlTotal 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

GetDiskInfoA = ctypes.windll.wininet.GetDiskInfoA
GetDiskInfoA.restype = wintypes.BOOL
GetDiskInfoA.argtypes = [
    wintypes.LPCSTR,  # pszPath : LPCSTR
    ctypes.POINTER(wintypes.DWORD),  # pdwClusterSize : DWORD* optional, out
    ctypes.POINTER(ctypes.c_ulonglong),  # pdlAvail : ULONGLONG* optional, out
    ctypes.POINTER(ctypes.c_ulonglong),  # pdlTotal : ULONGLONG* optional, out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('WININET.dll')
GetDiskInfoA = Fiddle::Function.new(
  lib['GetDiskInfoA'],
  [
    Fiddle::TYPE_VOIDP,  # pszPath : LPCSTR
    Fiddle::TYPE_VOIDP,  # pdwClusterSize : DWORD* optional, out
    Fiddle::TYPE_VOIDP,  # pdlAvail : ULONGLONG* optional, out
    Fiddle::TYPE_VOIDP,  # pdlTotal : ULONGLONG* optional, out
  ],
  Fiddle::TYPE_INT)

#[link(name = "wininet")]
extern "system" {
    fn GetDiskInfoA(
        pszPath: *const u8,  // LPCSTR
        pdwClusterSize: *mut u32,  // DWORD* optional, out
        pdlAvail: *mut u64,  // ULONGLONG* optional, out
        pdlTotal: *mut u64  // ULONGLONG* optional, out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("WININET.dll")]
public static extern bool GetDiskInfoA([MarshalAs(UnmanagedType.LPStr)] string pszPath, IntPtr pdwClusterSize, IntPtr pdlAvail, IntPtr pdlTotal);
"@
$api = Add-Type -MemberDefinition $sig -Name 'WININET_GetDiskInfoA' -Namespace Win32 -PassThru
# $api::GetDiskInfoA(pszPath, pdwClusterSize, pdlAvail, pdlTotal)

#uselib "WININET.dll"
#func global GetDiskInfoA "GetDiskInfoA" sptr, sptr, sptr, sptr
; GetDiskInfoA pszPath, varptr(pdwClusterSize), varptr(pdlAvail), varptr(pdlTotal)   ; 戻り値は stat
; pszPath : LPCSTR -> "sptr"
; pdwClusterSize : DWORD* optional, out -> "sptr"
; pdlAvail : ULONGLONG* optional, out -> "sptr"
; pdlTotal : ULONGLONG* 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 "WININET.dll"
#cfunc global GetDiskInfoA "GetDiskInfoA" str, var, var, var
; res = GetDiskInfoA(pszPath, pdwClusterSize, pdlAvail, pdlTotal)
; pszPath : LPCSTR -> "str"
; pdwClusterSize : DWORD* optional, out -> "var"
; pdlAvail : ULONGLONG* optional, out -> "var"
; pdlTotal : ULONGLONG* 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。

; BOOL GetDiskInfoA(LPCSTR pszPath, DWORD* pdwClusterSize, ULONGLONG* pdlAvail, ULONGLONG* pdlTotal)
#uselib "WININET.dll"
#cfunc global GetDiskInfoA "GetDiskInfoA" str, var, var, var
; res = GetDiskInfoA(pszPath, pdwClusterSize, pdlAvail, pdlTotal)
; pszPath : LPCSTR -> "str"
; pdwClusterSize : DWORD* optional, out -> "var"
; pdlAvail : ULONGLONG* optional, out -> "var"
; pdlTotal : ULONGLONG* 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 (
	wininet = windows.NewLazySystemDLL("WININET.dll")
	procGetDiskInfoA = wininet.NewProc("GetDiskInfoA")
)

// pszPath (LPCSTR), pdwClusterSize (DWORD* optional, out), pdlAvail (ULONGLONG* optional, out), pdlTotal (ULONGLONG* optional, out)
r1, _, err := procGetDiskInfoA.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(pszPath))),
	uintptr(pdwClusterSize),
	uintptr(pdlAvail),
	uintptr(pdlTotal),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function GetDiskInfoA(
  pszPath: PAnsiChar;   // LPCSTR
  pdwClusterSize: Pointer;   // DWORD* optional, out
  pdlAvail: Pointer;   // ULONGLONG* optional, out
  pdlTotal: Pointer   // ULONGLONG* optional, out
): BOOL; stdcall;
  external 'WININET.dll' name 'GetDiskInfoA';

result := DllCall("WININET\GetDiskInfoA"
    , "AStr", pszPath   ; LPCSTR
    , "Ptr", pdwClusterSize   ; DWORD* optional, out
    , "Ptr", pdlAvail   ; ULONGLONG* optional, out
    , "Ptr", pdlTotal   ; ULONGLONG* optional, out
    , "Int")   ; return: BOOL

●GetDiskInfoA(pszPath, pdwClusterSize, pdlAvail, pdlTotal) = DLL("WININET.dll", "bool GetDiskInfoA(char*, void*, void*, void*)")
# 呼び出し: GetDiskInfoA(pszPath, pdwClusterSize, pdlAvail, pdlTotal)
# pszPath : LPCSTR -> "char*"
# pdwClusterSize : DWORD* optional, out -> "void*"
# pdlAvail : ULONGLONG* optional, out -> "void*"
# pdlTotal : ULONGLONG* 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)。