Git - The .git directory

From EdWiki

GitLab - The .git directory

  • Goals
    Learn about the structure of the .git directory
  • The .git Directory

Time to do some exploring. First, from the root of your project directory…

ls -C .git

This is the magic directory where all the git “stuff” is stored. Let’s peek in the objects directory.

  • The Object Store
ls -C .git/objects

You should see a bunch of directories with 2 letter names. The directory names are the first two letters of the sha1 hash of the object stored in git.

  • Deeper into the Object Store
ls -C .git/objects/<dir>

Look in one of the two-letter directories. You should see some files with 38-character names. These are the files that contain the objects stored in git. These files are compressed and encoded, so looking at their contents directly won’t be very helpful, but we will take a closer look in a bit.

  • Config File
cat .git/config

This is a project-specific configuration file. Config entries in here will override the config entries in the .gitconfig file in your home directory, at least for this project.

  • Branches and Tags
ls .git/refs
ls .git/refs/heads
ls .git/refs/tags
cat .git/refs/tags/v1

You should recognize the files in the tags subdirectory. Each file corresponds to a tag you created with the git tag command earlier. Its content is just the hash of the commit tied to the tag.

The heads directory is similar, but is used for branches rather than tags. We only have one branch at the moment, so all you will see is master in this directory.

  • The HEAD File
cat .git/HEAD

The HEAD file contains a reference to the current branch. It should be a reference to master at this point.