How to extract a git subdirectory and make a submodule out of it?

Question

I started a project some months ago and stored everything within a main directory. In my main directory \"Project\" there are several subdirectories containing different thi

Answer 1

Checkout git filter-branch.

The Examples section of the man page shows how to extract a sub-directory into it's own project while keeping all of it's history and discarding history of other files/directories (just what you're looking for).

To rewrite the repository to look as if foodir/ had been its project root, and discard all other history:

   git filter-branch --subdirectory-filter foodir -- --all

Thus you can, e.g., turn a library subdirectory into a repository of its own.
Note the -- that separates filter-branch options from revision options, and the --all to rewrite all branches and tags.