A Guide to Git Submodules: Managing Dependent Code in Projects

Git submodules are tools for reusing independent code (such as common libraries) in large projects, solving problems like duplicate copying and version synchronization. Core advantages include: space savings through code reuse, independent maintenance for easy modification and submission, and version specification by the main project to ensure consistency. Essentially, submodules are independent Git repositories, with the main project recording configurations and version references via .gitmodules and .git/config. Core usage steps: Add submodules to the main project using `git submodule add`; clone projects with submodules using `--recursive`, otherwise use `init+update`; commit main project references after modifying submodules; update with `git submodule update`; clean configurations when deleting submodules. Common issues: Empty repositories after cloning (supplement with `--recursive` or `update`), unupdated main project after submodule modifications (supplement with commits), version conflicts (agree on branches). Summary: Suitable for independently reusable dependencies, following the process: add → clone/update → modify and commit → update main project references, improving maintenance efficiency.