EnumProcesses

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

BOOL EnumProcesses(
    DWORD* lpidProcess,
    DWORD cb,
    DWORD* lpcbNeeded
);

<DllImport("PSAPI.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function EnumProcesses(
    <Out> ByRef lpidProcess As UInteger,   ' DWORD* out
    cb As UInteger,   ' DWORD
    <Out> ByRef lpcbNeeded As UInteger   ' DWORD* out
) As Boolean
End Function

' lpidProcess : DWORD* out
' cb : DWORD
' lpcbNeeded : DWORD* out
Declare PtrSafe Function EnumProcesses Lib "psapi" ( _
    ByRef lpidProcess As Long, _
    ByVal cb As Long, _
    ByRef lpcbNeeded 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

EnumProcesses = ctypes.windll.psapi.EnumProcesses
EnumProcesses.restype = wintypes.BOOL
EnumProcesses.argtypes = [
    ctypes.POINTER(wintypes.DWORD),  # lpidProcess : DWORD* out
    wintypes.DWORD,  # cb : DWORD
    ctypes.POINTER(wintypes.DWORD),  # lpcbNeeded : DWORD* out
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('PSAPI.dll')
EnumProcesses = Fiddle::Function.new(
  lib['EnumProcesses'],
  [
    Fiddle::TYPE_VOIDP,  # lpidProcess : DWORD* out
    -Fiddle::TYPE_INT,  # cb : DWORD
    Fiddle::TYPE_VOIDP,  # lpcbNeeded : DWORD* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "psapi")]
extern "system" {
    fn EnumProcesses(
        lpidProcess: *mut u32,  // DWORD* out
        cb: u32,  // DWORD
        lpcbNeeded: *mut u32  // DWORD* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("PSAPI.dll", SetLastError = true)]
public static extern bool EnumProcesses(out uint lpidProcess, uint cb, out uint lpcbNeeded);
"@
$api = Add-Type -MemberDefinition $sig -Name 'PSAPI_EnumProcesses' -Namespace Win32 -PassThru
# $api::EnumProcesses(lpidProcess, cb, lpcbNeeded)

#uselib "PSAPI.dll"
#func global EnumProcesses "EnumProcesses" sptr, sptr, sptr
; EnumProcesses varptr(lpidProcess), cb, varptr(lpcbNeeded)   ; 戻り値は stat
; lpidProcess : DWORD* out -> "sptr"
; cb : DWORD -> "sptr"
; lpcbNeeded : DWORD* 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 "PSAPI.dll"
#cfunc global EnumProcesses "EnumProcesses" var, int, var
; res = EnumProcesses(lpidProcess, cb, lpcbNeeded)
; lpidProcess : DWORD* out -> "var"
; cb : DWORD -> "int"
; lpcbNeeded : DWORD* 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 EnumProcesses(DWORD* lpidProcess, DWORD cb, DWORD* lpcbNeeded)
#uselib "PSAPI.dll"
#cfunc global EnumProcesses "EnumProcesses" var, int, var
; res = EnumProcesses(lpidProcess, cb, lpcbNeeded)
; lpidProcess : DWORD* out -> "var"
; cb : DWORD -> "int"
; lpcbNeeded : DWORD* 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 (
	psapi = windows.NewLazySystemDLL("PSAPI.dll")
	procEnumProcesses = psapi.NewProc("EnumProcesses")
)

// lpidProcess (DWORD* out), cb (DWORD), lpcbNeeded (DWORD* out)
r1, _, err := procEnumProcesses.Call(
	uintptr(lpidProcess),
	uintptr(cb),
	uintptr(lpcbNeeded),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function EnumProcesses(
  lpidProcess: Pointer;   // DWORD* out
  cb: DWORD;   // DWORD
  lpcbNeeded: Pointer   // DWORD* out
): BOOL; stdcall;
  external 'PSAPI.dll' name 'EnumProcesses';

result := DllCall("PSAPI\EnumProcesses"
    , "Ptr", lpidProcess   ; DWORD* out
    , "UInt", cb   ; DWORD
    , "Ptr", lpcbNeeded   ; DWORD* out
    , "Int")   ; return: BOOL

●EnumProcesses(lpidProcess, cb, lpcbNeeded) = DLL("PSAPI.dll", "bool EnumProcesses(void*, dword, void*)")
# 呼び出し: EnumProcesses(lpidProcess, cb, lpcbNeeded)
# lpidProcess : DWORD* out -> "void*"
# cb : DWORD -> "dword"
# lpcbNeeded : DWORD* 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)。