BackupSeek

関数

バックアップストリーム内を指定バイト分シークする。

DLLKERNEL32.dll呼出規約winapiSetLastErrorあり対応OSWindows XP 以降

シグネチャ

// KERNEL32.dll
#include <windows.h>

BOOL BackupSeek(
    HANDLE hFile,
    DWORD dwLowBytesToSeek,
    DWORD dwHighBytesToSeek,
    DWORD* lpdwLowByteSeeked,
    DWORD* lpdwHighByteSeeked,
    void** lpContext
);

パラメーター

名前	型	方向
hFile	HANDLE	in
dwLowBytesToSeek	DWORD	in
dwHighBytesToSeek	DWORD	in
lpdwLowByteSeeked	DWORD*	out
lpdwHighByteSeeked	DWORD*	out
lpContext	void**	inout

戻り値の型: BOOL

各言語での呼び出し定義

// KERNEL32.dll
#include <windows.h>

BOOL BackupSeek(
    HANDLE hFile,
    DWORD dwLowBytesToSeek,
    DWORD dwHighBytesToSeek,
    DWORD* lpdwLowByteSeeked,
    DWORD* lpdwHighByteSeeked,
    void** lpContext
);

[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("KERNEL32.dll", SetLastError = true, ExactSpelling = true)]
static extern bool BackupSeek(
    IntPtr hFile,   // HANDLE
    uint dwLowBytesToSeek,   // DWORD
    uint dwHighBytesToSeek,   // DWORD
    out uint lpdwLowByteSeeked,   // DWORD* out
    out uint lpdwHighByteSeeked,   // DWORD* out
    IntPtr lpContext   // void** in/out
);

<DllImport("KERNEL32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function BackupSeek(
    hFile As IntPtr,   ' HANDLE
    dwLowBytesToSeek As UInteger,   ' DWORD
    dwHighBytesToSeek As UInteger,   ' DWORD
    <Out> ByRef lpdwLowByteSeeked As UInteger,   ' DWORD* out
    <Out> ByRef lpdwHighByteSeeked As UInteger,   ' DWORD* out
    lpContext As IntPtr   ' void** in/out
) As Boolean
End Function

' hFile : HANDLE
' dwLowBytesToSeek : DWORD
' dwHighBytesToSeek : DWORD
' lpdwLowByteSeeked : DWORD* out
' lpdwHighByteSeeked : DWORD* out
' lpContext : void** in/out
Declare PtrSafe Function BackupSeek Lib "kernel32" ( _
    ByVal hFile As LongPtr, _
    ByVal dwLowBytesToSeek As Long, _
    ByVal dwHighBytesToSeek As Long, _
    ByRef lpdwLowByteSeeked As Long, _
    ByRef lpdwHighByteSeeked As Long, _
    ByVal lpContext 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

BackupSeek = ctypes.windll.kernel32.BackupSeek
BackupSeek.restype = wintypes.BOOL
BackupSeek.argtypes = [
    wintypes.HANDLE,  # hFile : HANDLE
    wintypes.DWORD,  # dwLowBytesToSeek : DWORD
    wintypes.DWORD,  # dwHighBytesToSeek : DWORD
    ctypes.POINTER(wintypes.DWORD),  # lpdwLowByteSeeked : DWORD* out
    ctypes.POINTER(wintypes.DWORD),  # lpdwHighByteSeeked : DWORD* out
    ctypes.c_void_p,  # lpContext : void** in/out
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
BackupSeek = Fiddle::Function.new(
  lib['BackupSeek'],
  [
    Fiddle::TYPE_VOIDP,  # hFile : HANDLE
    -Fiddle::TYPE_INT,  # dwLowBytesToSeek : DWORD
    -Fiddle::TYPE_INT,  # dwHighBytesToSeek : DWORD
    Fiddle::TYPE_VOIDP,  # lpdwLowByteSeeked : DWORD* out
    Fiddle::TYPE_VOIDP,  # lpdwHighByteSeeked : DWORD* out
    Fiddle::TYPE_VOIDP,  # lpContext : void** in/out
  ],
  Fiddle::TYPE_INT)

#[link(name = "kernel32")]
extern "system" {
    fn BackupSeek(
        hFile: *mut core::ffi::c_void,  // HANDLE
        dwLowBytesToSeek: u32,  // DWORD
        dwHighBytesToSeek: u32,  // DWORD
        lpdwLowByteSeeked: *mut u32,  // DWORD* out
        lpdwHighByteSeeked: *mut u32,  // DWORD* out
        lpContext: *mut *mut ()  // void** in/out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("KERNEL32.dll", SetLastError = true)]
public static extern bool BackupSeek(IntPtr hFile, uint dwLowBytesToSeek, uint dwHighBytesToSeek, out uint lpdwLowByteSeeked, out uint lpdwHighByteSeeked, IntPtr lpContext);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_BackupSeek' -Namespace Win32 -PassThru
# $api::BackupSeek(hFile, dwLowBytesToSeek, dwHighBytesToSeek, lpdwLowByteSeeked, lpdwHighByteSeeked, lpContext)

#uselib "KERNEL32.dll"
#func global BackupSeek "BackupSeek" sptr, sptr, sptr, sptr, sptr, sptr
; BackupSeek hFile, dwLowBytesToSeek, dwHighBytesToSeek, varptr(lpdwLowByteSeeked), varptr(lpdwHighByteSeeked), lpContext   ; 戻り値は stat
; hFile : HANDLE -> "sptr"
; dwLowBytesToSeek : DWORD -> "sptr"
; dwHighBytesToSeek : DWORD -> "sptr"
; lpdwLowByteSeeked : DWORD* out -> "sptr"
; lpdwHighByteSeeked : DWORD* out -> "sptr"
; lpContext : void** in/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。

出力引数:

#uselib "KERNEL32.dll"
#cfunc global BackupSeek "BackupSeek" sptr, int, int, var, var, sptr
; res = BackupSeek(hFile, dwLowBytesToSeek, dwHighBytesToSeek, lpdwLowByteSeeked, lpdwHighByteSeeked, lpContext)
; hFile : HANDLE -> "sptr"
; dwLowBytesToSeek : DWORD -> "int"
; dwHighBytesToSeek : DWORD -> "int"
; lpdwLowByteSeeked : DWORD* out -> "var"
; lpdwHighByteSeeked : DWORD* out -> "var"
; lpContext : void** in/out -> "sptr"
; ※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。#uselib "KERNEL32.dll"
#cfunc global BackupSeek "BackupSeek" sptr, int, int, sptr, sptr, sptr
; res = BackupSeek(hFile, dwLowBytesToSeek, dwHighBytesToSeek, varptr(lpdwLowByteSeeked), varptr(lpdwHighByteSeeked), lpContext)
; hFile : HANDLE -> "sptr"
; dwLowBytesToSeek : DWORD -> "int"
; dwHighBytesToSeek : DWORD -> "int"
; lpdwLowByteSeeked : DWORD* out -> "sptr"
; lpdwHighByteSeeked : DWORD* out -> "sptr"
; lpContext : void** in/out -> "sptr"
; ※出力/バッファ引数はポインタ方式(token=sptr / 呼び出しは varptr(変数))。

出力引数:

; BOOL BackupSeek(HANDLE hFile, DWORD dwLowBytesToSeek, DWORD dwHighBytesToSeek, DWORD* lpdwLowByteSeeked, DWORD* lpdwHighByteSeeked, void** lpContext)
#uselib "KERNEL32.dll"
#cfunc global BackupSeek "BackupSeek" intptr, int, int, var, var, intptr
; res = BackupSeek(hFile, dwLowBytesToSeek, dwHighBytesToSeek, lpdwLowByteSeeked, lpdwHighByteSeeked, lpContext)
; hFile : HANDLE -> "intptr"
; dwLowBytesToSeek : DWORD -> "int"
; dwHighBytesToSeek : DWORD -> "int"
; lpdwLowByteSeeked : DWORD* out -> "var"
; lpdwHighByteSeeked : DWORD* out -> "var"
; lpContext : void** in/out -> "intptr"
; ※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 BackupSeek(HANDLE hFile, DWORD dwLowBytesToSeek, DWORD dwHighBytesToSeek, DWORD* lpdwLowByteSeeked, DWORD* lpdwHighByteSeeked, void** lpContext)
#uselib "KERNEL32.dll"
#cfunc global BackupSeek "BackupSeek" intptr, int, int, intptr, intptr, intptr
; res = BackupSeek(hFile, dwLowBytesToSeek, dwHighBytesToSeek, varptr(lpdwLowByteSeeked), varptr(lpdwHighByteSeeked), lpContext)
; hFile : HANDLE -> "intptr"
; dwLowBytesToSeek : DWORD -> "int"
; dwHighBytesToSeek : DWORD -> "int"
; lpdwLowByteSeeked : DWORD* out -> "intptr"
; lpdwHighByteSeeked : DWORD* out -> "intptr"
; lpContext : void** in/out -> "intptr"
; ※出力/バッファ引数はポインタ方式(token=intptr / 呼び出しは varptr(変数))。

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

var (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	procBackupSeek = kernel32.NewProc("BackupSeek")
)

// hFile (HANDLE), dwLowBytesToSeek (DWORD), dwHighBytesToSeek (DWORD), lpdwLowByteSeeked (DWORD* out), lpdwHighByteSeeked (DWORD* out), lpContext (void** in/out)
r1, _, err := procBackupSeek.Call(
	uintptr(hFile),
	uintptr(dwLowBytesToSeek),
	uintptr(dwHighBytesToSeek),
	uintptr(lpdwLowByteSeeked),
	uintptr(lpdwHighByteSeeked),
	uintptr(lpContext),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function BackupSeek(
  hFile: THandle;   // HANDLE
  dwLowBytesToSeek: DWORD;   // DWORD
  dwHighBytesToSeek: DWORD;   // DWORD
  lpdwLowByteSeeked: Pointer;   // DWORD* out
  lpdwHighByteSeeked: Pointer;   // DWORD* out
  lpContext: Pointer   // void** in/out
): BOOL; stdcall;
  external 'KERNEL32.dll' name 'BackupSeek';

result := DllCall("KERNEL32\BackupSeek"
    , "Ptr", hFile   ; HANDLE
    , "UInt", dwLowBytesToSeek   ; DWORD
    , "UInt", dwHighBytesToSeek   ; DWORD
    , "Ptr", lpdwLowByteSeeked   ; DWORD* out
    , "Ptr", lpdwHighByteSeeked   ; DWORD* out
    , "Ptr", lpContext   ; void** in/out
    , "Int")   ; return: BOOL

●BackupSeek(hFile, dwLowBytesToSeek, dwHighBytesToSeek, lpdwLowByteSeeked, lpdwHighByteSeeked, lpContext) = DLL("KERNEL32.dll", "bool BackupSeek(void*, dword, dword, void*, void*, void*)")
# 呼び出し: BackupSeek(hFile, dwLowBytesToSeek, dwHighBytesToSeek, lpdwLowByteSeeked, lpdwHighByteSeeked, lpContext)
# hFile : HANDLE -> "void*"
# dwLowBytesToSeek : DWORD -> "dword"
# dwHighBytesToSeek : DWORD -> "dword"
# lpdwLowByteSeeked : DWORD* out -> "void*"
# lpdwHighByteSeeked : DWORD* out -> "void*"
# lpContext : void** in/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)。