Virtual copies of files in SVN?

I'm guesin开发者_Go百科g if its possible to have virtual copies of my code with SVN. For example: imagine that I have two programs in my repository. Program A use a subset of files used by B.

My question is if I could update a copy of a file in the context of program A, then commit in SVN and next time I update my code, I have the same copy in program A and B without the need to copy by hand this file.

It is posible? some help would be welcome

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You should look into externals - there's also a post here on how to get started.

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If you could use a special directory construction you could just check out your B to your A,
then add it to ignore in A. Then you can update in B directory.