This is my first question here so I hope it is not off topic. Although I am using the Linux inotify library to listen for changes to files, and I compare use of that against the Subversion program, I am specifically looking for the algorithm used.
To a human it is very easy to tell if a file has been created or modified. Clicking the New button constitutes the former, and clicking the Save button constitutes the latter. To Linux, both those actions have serious overlap. In text editors, for example, generally a swap file is created and then copied/moved. This makes it difficult to distinguish via inotify between a minor edit to a file and a deliberate overwrite of a file. What I am trying to understand is how a program such as Subversion recognizes the difference between a user having modified a file with a text editor, and a user having actually deleted the file and opened a new file with the same name.
Edit:
It has been pointed out that subversion does not do what I want it to do, so it was a blunder on my part to use it as an example. Instead allow me to rephrase the question: "Is there any known program or programming approach to match high level actions such as creating new files and saving them to low level actions such as modifying, moving, copying, etc. such that I can log all the files in the system and changes to them"?
Best Answer
If you want to learn how subversion does to understand the working directory, you can look at the source pretty easily. As a longtime SVN user, I can pretty confidently say that SVN does not make any distinction at all to what happens to a file before the commit -- it just checks against what you are committing against the repository. Nothing more, nothing less.