问题
I know that when you add a submodule to a git repository it tracks a particular commit of that submodule referenced by its sha1.
I'm trying to find where this sha1 value is stored.
The .gitmodules and .git/config files only show the paths for the submodule, but not the sha1 of the commit.
The git-submodule(1) reference only speaks of a gitlink entry and the gitmodules(5) reference doesn't say anything about this either.
回答1:
It is stored in Git's object database directly. The tree object for the directory where the submodule lives will have an entry for the submodule's commit (this is the so-called "gitlink").
Try doing git ls-tree master <path-to-directory-containing-submodule> (or just git ls-tree master if the submodule lives in the top-level directory).
来源：https://stackoverflow.com/questions/5033441/where-does-git-store-the-sha1-of-the-commit-for-a-submodule