GetFileSize

The GetFileSize function retrieves the size, in bytes, of the specified file.

DWORD GetFileSize(
  HANDLE hFile,  // handle of file to get size of
  LPDWORD lpFileSizeHigh 
                 // pointer to high-order word for file size
);
 

Parameters

hFile

Specifies an open handle of the file whose size is being returned. The handle must have been created with either GENERIC_READ or GENERIC_WRITE access to the file.

lpFileSizeHigh

Pointer to the variable where the high-order word of the file size is returned. This parameter can be NULL if the application does not require the high-order word.

Return Values

If the function succeeds, the return value is the low-order doubleword of the file size, and, if lpFileSizeHigh is non-NULL, the function puts the high-order doubleword of the file size into the variable pointed to by that parameter.

If the function fails and lpFileSizeHigh is NULL, the return value is 0xFFFFFFFF. To get extended error information, call GetLastError.

If the function fails and lpFileSizeHigh is non-NULL, the return value is 0xFFFFFFFF and GetLastError will return a value other than NO_ERROR.

Remarks

You cannot use the GetFileSize function with a handle of a nonseeking device such as a pipe or a communications device. To determine the file type for hFile, use the GetFileType function.

The GetFileSize function obtains the uncompressed size of a file. Use the GetCompressedFileSize function to obtain the compressed size of a file.

Note that if the return value is 0xFFFFFFFF and lpFileSizeHigh is non-NULL, an application must call GetLastError to determine whether the function has succeeded or failed. The following sample code illustrates this point:

// 
// Case One: calling the function with 
//           lpFileSizeHigh == NULL 
 
// Try to obtain hFile's size 
dwSize = GetFileSize (hFile, NULL) ; 
 
// If we failed ... 
if (dwSize == 0xFFFFFFFF) { 
 
    // Obtain the error code. 
    dwError = GetLastError() ; 
 
    // Deal with that failure. 
    . 
    . 
    . 
 
    } // End of error handler 
 
 
// 
// Case Two: calling the function with 
//           lpFileSizeHigh != NULL 
 
// Try to obtain hFile's huge size. 
dwSizeLow = GetFileSize (hFile, & dwSizeHigh) ; 
 
// If we failed ... 
if (dwSizeLow == 0xFFFFFFFF 
    && 
    (dwError = GetLastError()) != NO_ERROR ){ 
 
    // Deal with that failure. 
    . 
    . 
    . 
 
    } // End of error handler. 
 

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winbase.h.
  Import Library: Use kernel32.lib.

See Also

File I/O Overview, File Functions, GetCompressedFileSize, GetFileType