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Partha Dasgupta


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Active Files

 Files have traditionally been passive, persistent, uninterpreted sequence of bytes.

Active Files are a simple, elegant, programmable method for associating activity with data. An Active File is a regular file that is accessed though a sentinel process. The sentinel process is automatically started when the file is opened, and lives until the file is closed. In addition to filtering all accesses to and from the file, the sentinel process is also capable of producing side effects for each access. However, more importantly, the integration of active files into client applications is transparent: an active file is almost indistinguishable from a regular file and is accessed using a conventional file interface. The applications of active files are wide and far-reaching, unifying several of the above approaches.

More Information: A paper on this topic is here (PDF