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Q88769: HOWTO: Test for End of File with CFile and CStdioFile

Article: Q88769
Product(s): Microsoft C Compiler
Version(s): winnt:1.0,2.0,2.1,2.2,4.0
Operating System(s): 
Keyword(s): kbFileIO kbMFC kbVC100 kbVC150 kbVC200 kbVC400 kbGrpDSMFCATL
Last Modified: 03-MAY-2001

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The information in this article applies to:

- The Microsoft Foundation Classes (MFC), used with:
   - Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5, 1.51, 1.52 
   - Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 2.1, 2.2, 4.0 
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SUMMARY
=======

The Microsoft Foundation Classes (MFC) provide a CFileException class. The
CFileException class includes public data members that contain operating- system
errors and C Run-time errors that may be generated by certain file operations.

MORE INFORMATION
================

The CFile and CStdioFile classes may throw a CFileException when certain error
conditions occur; however, these classes do not throw a CFileException when the
end of file is reached. If an application using the CFile or CStdioFile class
needs to check for the end-of-file condition when reading from a file, the
return values from the Read() and ReadString() member functions should be
checked.

CFile::Read returns the actual number of bytes read. If this number is less than
the bytes requested, then the end of file has been reached.

CStdioFile::ReadString returns a NULL pointer when the end of file has been
reached.

Additional query words: EOF TRY CATCH

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Keywords          : kbFileIO kbMFC kbVC100 kbVC150 kbVC200 kbVC400 kbGrpDSMFCATL 
Technology        : kbAudDeveloper kbMFC
Version           : winnt:1.0,2.0,2.1,2.2,4.0
Issue type        : kbhowto

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