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ActivePython 2.4 Documentation

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win32file.ReadFile

(int, string) = ReadFile(hFile, buffer/bufSize , ol )

Reads a string from a file

Parameters

hFile : PyHANDLE/int

Handle to the file

buffer/bufSize : PyOVERLAPPEDReadBuffer/int

Size of the buffer to create for the read. If a multi-threaded overlapped operation is performed, a buffer object can be passed. If a buffer object is passed, the result is the buffer itself.

ol=None : PyOVERLAPPED

An overlapped structure

Comments

in a multi-threaded overlapped environment, it is likely to be necessary to pre-allocate the read buffer using the win32file::AllocateReadBuffer method, otherwise the I/O operation may complete before you can assign to the resulting buffer.

Return Value

The result is a tuple of (hr, string/PyOVERLAPPEDReadBuffer), where hr may be 0, ERROR_MORE_DATA or ERROR_IO_PENDING. If the overlapped param is not None, then the result is a PyOVERLAPPEDReadBuffer. Once the overlapped IO operation has completed, you can convert this to a string (str(object))to obtain the data. While the operation is in progress, you can use the slice operations (object[:end]) to obtain the data read so far. You must use the OVERLAPPED API functions to determine how much of the data is valid.