函数参考

_WinAPI_BackupRead

Backs up a file or directory, including the security information.

#Include <WinAPIEx.au3>
_WinAPI_BackupRead ( $hFile, $pBuffer, $iLength, ByRef $iBytes, ByRef $pContext [, $fSecurity] )

参数

$hFile Handle to the file or directory to be backed up. To obtain the handle, call the _WinAPI_CreateFileEx()
function. The SACLs are not read unless the file handle was created with the $ACCESS_SYSTEM_SECURITY
access right.
$pBuffer A pointer to a buffer that receives the data.
$iLength The size of the buffer, in bytes. The buffer size must be greater than the size of the
$tagWIN32_STREAM_ID structure (查看MSDN得到更多信息).
$iBytes The number of bytes read.
$pContext A pointer to an internal data structure used by this function to maintain context information during
a backup operation. You must set this variable to 0 before the first call to _WinAPI_BackupRead()
for the specified file or directory. The function allocates memory for the data structure, and then
sets the variable to point to that structure. You must not change this variable or the variable
that it points to between calls to _WinAPI_BackupRead().
$fSecurity [可选参数] Specifies whether the function will backup the access-control list (ACL) data, valid values:
TRUE - The ACL data will be backed up.
FALSE - The ACL data will be omitted. (Default)

返回值

成功: 返回 1.
失败: 返回 0 并设置 @error 标志为非 0 值.

注意/说明

The _WinAPI_BackupRead() is not intended for use in backing up files encrypted under the Encrypted File System (EFS).

If an error occurs during the data reading, the calling process can skip the bad data by calling the
_WinAPI_BackupSeek() function.

When you are done using _WinAPI_BackupRead(), you must call _WinAPI_BackupReadAbort() function with the appropriate
parameter to release the memory used by the internal data structure.

The file or directory should be restored using the _WinAPI_BackupWrite() function.

相关

详情参考

在MSDN中搜索


示例/演示


#Include <APIConstants.au3>
#Include <WinAPIEx.au3>

Opt('MustDeclareVars', 1)

Global Const $sFile = @ScriptFullPath

Global $aAdjust, $aPrivileges[2] = [$SE_BACKUP_NAME, $SE_RESTORE_NAME]
Global $Bytes = 4096 + FileGetSize($sFile)
Global $hFile, $pBuffer, $pContext

; Enable "SeBackupPrivilege" and "SeRestorePrivilege" privileges to perform backup and restore operation
$hToken = _WinAPI_OpenProcessToken(BitOR($TOKEN_ADJUST_PRIVILEGES, $TOKEN_QUERY))
_WinAPI_AdjustTokenPrivileges($hToken, $aPrivileges, $SE_PRIVILEGE_ENABLED, $aAdjust)
If @error Or @extended Then
    MsgBox(16, 'Error', 'You do not have the required privileges.')
    Exit
EndIf

; Create a memory buffer where to store the backup data
$pBuffer = _WinAPI_CreateBuffer($Bytes)

; Back up a file, including the security information
$pContext = 0
$hFile = _WinAPI_CreateFileEx($sFile, $OPEN_EXISTING, $GENERIC_READ)
_WinAPI_BackupRead($hFile, $pBuffer, $Bytes, $Bytes, $pContext, 1)
If @error Then
    MsgBox(16, 'Error', 'Unable to back up a file.')
    Exit
EndIf
_WinAPI_BackupReadAbort($pContext)
_WinAPI_CloseHandle($hFile)

; Restore a file (.bak) and the ACL data
$pContext = 0
$hFile = _WinAPI_CreateFileEx(_WinAPI_PathRenameExtension($sFile, '.bak'), $CREATE_ALWAYS, BitOR($GENERIC_WRITE, $WRITE_DAC, $WRITE_OWNER))
_WinAPI_BackupWrite($hFile, $pBuffer, $Bytes, $Bytes, $pContext, 1)
If @error Then
    MsgBox(16, 'Error', 'Unable to restore a file.')
    Exit
EndIf
_WinAPI_BackupWriteAbort($pContext)
_WinAPI_CloseHandle($hFile)

; Free the used memory
_WinAPI_FreeMemory($pBuffer)

; Restore "SeBackupPrivilege" and "SeRestorePrivilege" privileges by default
_WinAPI_AdjustTokenPrivileges($hToken, $aAdjust, 0, $aAdjust)
_WinAPI_CloseHandle($hToken)