hook into a file, read new content in real time

Question

How would I hook into a file that's currently in use by another program, which constantly writes out to it? Let's say, there's a text file with 10 lines. When I start my app it has to detect and read any content from there on everytime the writing program saves its content. Can this be done without a constant check on the filesize/date?

score 3 · Answer 1 · edited May 23 '17 at 11:55

3

You could monitor the folder for changes using the ReadDirectoryChangesW API.

Keep track of the last position you read to, and when you receive a change notification for that file, read from there to the end of the file (as it currently stands).

An example of how to use the ReadDirectoryChangesW API is here:

Why does ReadDirectoryChangesW omit events?

edited May 23 '17 at 11:55

Community

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answered Jun 22 '11 at 04:26

Nat

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score 2 · Answer 2 · edited May 23 '17 at 10:33

2

Kinda similar to this: Monitor files similar to System Internal's/Microsoft's FileMon/Process Monitor

edited May 23 '17 at 10:33

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answered Jun 21 '11 at 15:50

Chris Thornton

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hook into a file, read new content in real time

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