I am curious about why the file size stop at 96 or another size while the application is continuously writing data into it and the file size suddenly changes when the app ends. How to explain this phenomenon?
It’s called “buffered I/O.” To use a metaphor: Typically, you don’t run to the store for every single item you may need during the week. (That would be unbuffered store access.) Instead, you build a shopping list and go to the store once. OK?