How to write a file when it is opened or used by another application?

Question

How to write a file when it is opened or used by another application?

If possible, how can this be done? If this is not possible, why is this so?

Answer 1

It all depends on the hosting platform. But keep in mind that changing the data that someone else uses, without it being designed to expect this, will produce an unpredictable result.

Think about how an “application” solves a problem whose data is given to you on a piece of paper.

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