Git Pocket Guide

Chapter 8. Naming Commits

Git has a variety of ways to refer to (or name, or “spell”) Git objects, usually commits, either individually or as a set, by following the commit graph or matching some criteria. You can find further detail on the conventions described next in gitrevisions(7).

The command git rev-parse is useful for checking your understanding: it will take a name in the various syntaxes presented here and translate it to an object ID, so you can make sure it refers to the object you expected. For names that represent sets of commits, git rev-list will show the resulting set.

Naming Individual Commits

Commit ID

The full SHA-1 object ID

For example, 2ee20b94203f22cc432d02cd5adb5ba610e6088f.

An abbreviated object ID

A prefix of an object’s full ID unique to your repository. So 2ee20b94 could name the same object as before, if no other object in your database has an ID beginning with those digits (if there were a conflict, you could just use a few more digits).

git describe

The output of the git describe command, which names commits relative to a tag; for example, v1.7.12-146-g16d26b16 refers to commit 16d26b16, which is 146 commits away from the tag v1.7.12. As output, this might be used as part of a build identifier, where it suggests to the reader the proximity of the build to a tag with a presumably helpful name. As input to Git however, only the trailing hex digits after -g are meaningful, and are used as an abbreviated commit ID.

Ref Name

A simple ref points directly ...