Reads data from a file
#include <WinAPIFiles.au3>
_WinAPI_ReadFile ( $hFile, $pBuffer, $iToRead, ByRef $iRead [, $tOverlapped = 0] )
| $hFile | Handle to the file to be read |
| $pBuffer | Pointer to the buffer that receives the data read from a file |
| $iToRead | Maximum number of bytes to read |
| $iRead | Number of bytes read |
| $tOverlapped | [optional] A $tagOVERLAPPED structure or a pointer to it |
| Success: | True |
| Failure: | False, call _WinAPI_GetLastError() to get extended error information |
$tagOVERLAPPED, _WinAPI_CloseHandle, _WinAPI_CreateFile, _WinAPI_FlushFileBuffers, _WinAPI_GetFileSizeEx, _WinAPI_SetEndOfFile, _WinAPI_SetFilePointer, _WinAPI_WriteFile
Search ReadFile in MSDN Library.
#include <WinAPIFiles.au3>
#include <WinAPIHObj.au3>
Local $sTempFile, $hFile, $sText, $nBytes, $tBuffer, $iSize
; 1) create file and write data to it
$sTempFile = @TempDir & '\test.txt'
$sText = 'abcdefghijklmnopqrstuvwxyz'
$tBuffer = DllStructCreate("byte[" & StringLen($sText) & "]")
DllStructSetData($tBuffer, 1, $sText)
$hFile = _WinAPI_CreateFile($sTempFile, 1)
_WinAPI_WriteFile($hFile, $tBuffer, StringLen($sText), $nBytes)
$iSize = _WinAPI_GetFileSizeEx($hFile)
_WinAPI_CloseHandle($hFile)
ConsoleWrite('1):' & $iSize & ' ' & FileRead($sTempFile) & @CRLF)
; 2) read 6 bytes from position 3
$tBuffer = DllStructCreate("byte[6]")
$hFile = _WinAPI_CreateFile($sTempFile, 2, 2)
$iSize = _WinAPI_GetFileSizeEx($hFile)
_WinAPI_SetFilePointer($hFile, 3)
_WinAPI_ReadFile($hFile, $tBuffer, 6, $nBytes)
_WinAPI_CloseHandle($hFile)
$sText = BinaryToString(DllStructGetData($tBuffer, 1))
ConsoleWrite('2):' & $iSize & ' ' & $sText & @CRLF)
; 3) write previously read 6 bytes from position 3 to the same position but in UpperCase
DllStructSetData($tBuffer, 1, StringUpper($sText))
$hFile = _WinAPI_CreateFile($sTempFile, 2, 4)
$iSize = _WinAPI_GetFileSizeEx($hFile)
_WinAPI_SetFilePointer($hFile, 3)
_WinAPI_WriteFile($hFile, $tBuffer, 6, $nBytes)
_WinAPI_CloseHandle($hFile)
$tBuffer = 0
ConsoleWrite('3):' & $iSize & ' ' & FileRead($sTempFile) & @CRLF)
; 4) truncate file size to 12 bytes
$hFile = _WinAPI_CreateFile($sTempFile, 2, 4)
_WinAPI_SetFilePointer($hFile, 12)
_WinAPI_SetEndOfFile($hFile)
$iSize = _WinAPI_GetFileSizeEx($hFile)
_WinAPI_CloseHandle($hFile)
ConsoleWrite('4):' & $iSize & ' ' & FileRead($sTempFile) & @CRLF)
FileDelete($sTempFile)