Back up of modified files

Hi all,
There are certain files (like doc, txt etc.) in a directory. I want to make an application which creates a back up of the files as soon as it has been closed after modification.
How can i approach that? Kindly Guide.

Call CopyFile to copy the original file in a new one before saving the modifications.

This function will help to be notified of modification: FindFirstChangeNotification()

Quote:

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Originally Posted by philkr

This function will help to be notified of modification: FindFirstChangeNotification()

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Code:

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dwChangeHandles[0] = FindFirstChangeNotification  (
"C:\\Test",                  // directory to watch
TRUE,                        // watch subtree

FILE_NOTIFY_CHANGE_ATTRIBUTES); // watch file attribute changes

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This notifies if any attributes are changed.I just want to know the files which aremodified & create their back up as soon as they are modified.
Please Help

ReadDirectoryChangesW() can notify you of all sorts of directory changes - for example, changed attributes, files added, files deleted, files modified, files renamed etc. However, it only works with Windows XP and 2000 as far as I'm aware.

what exactly u want ? can u explain?

Quote:

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Originally Posted by Gunaamirthavelu

what exactly u want ? can u explain?

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I want to be notified as soon as any file in a given directory is modified & then create its back up instantaneously.

Quote:

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Originally Posted by erankushmehta

FILE_NOTIFY_CHANGE_ATTRIBUTES); // watch file attribute changes [/CODE]

This notifies if any attributes are changed.I just want to know the files which aremodified & create their back up as soon as they are modified.
Please Help

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FILE_NOTIFY_CHANGE_ATTRIBUTES is not the only flag you can pass to the function. FILE_NOTIFY_CHANGE_LAST_WRITE is what you need.

If your target platforms match its requirements you should check the ReadDirectoryChangesW function as well. This is a function to be used in conjunction with FindFirstChangeNotification. With it you can pinpoint the changes occuring in a directory.

You can find a sample of its usage here: MSDN - fwatch

Another example is CodeProject - Directory Change Watcher

Quote:

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Originally Posted by PadexArt

FILE_NOTIFY_CHANGE_ATTRIBUTES is not the only flag you can pass to the function. FILE_NOTIFY_CHANGE_LAST_WRITE is what you need.

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Thanks, i get the notification.Now how to get the filename which was modified so that its back up may be created..

Quote:

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Originally Posted by erankushmehta

Thanks, i get the notification.Now how to get the filename which was modified so that its back up may be created..

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This information has been provided already. Read the posts to their full extent and follow the links.

ReadDirectoryChanges & FILE_NOTIFY_INFORMATION will do. But i am not able to comprehend the complex parameters & getting the relevant info from the file notify structure.

Follow PadexArt's link to the directory change watcher. Everything is wrapped up with ready-made handlers for OnFileAdded(0, OnFileRemoved(), OnFileModified(), and OnFileNameChanged(). They don't come much easier than that.

Code:

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if(!ReadDirectoryChangesW( pdi->m_hDir,
                                            pdi->m_Buffer,//<--FILE_NOTIFY_INFORMATION records are put into this buffer
                            READ_DIR_CHANGE_BUFFER_SIZE,
                            pdi->m_bWatchSubDir,
                            pdi->m_dwChangeFilter,
                            &pdi->m_dwBufLength,//this var not set when using asynchronous mechanisms...
                            &pdi->m_Overlapped,
                            NULL))

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i am getting following error:

Quote:

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error C2065: 'ReadDirectoryChangesW' : undeclared identifier

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I am using Windows 2000 Professional.

Try putting the following line in one of your header files (preferably stdafx.h )

Code:

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#define _WIN32_WINNT 0x400

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Quote:

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Originally Posted by John E

Try putting the following line in one of your header files (preferably stdafx.h )

Code:

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#define _WIN32_WINNT 0x400

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tried..but to no avail...

Plz help.