Progress:
TIER 2

Intermediate

Ancillary, foreign-SCM bridges, and pure helpers. Where porcelain stops being the whole story.

Welcome to Tier 2 — intermediate. The "I've been using Git for a year and I want to actually understand it" tier.

This tier is wider than it is deep. It covers the ancillary commands — the manipulators (config, reflog, repack, remote, replace), the interrogators (blame, fsck, count-objects, merge-tree), the foreign-SCM bridges (svn, p4, cvs — yes, still relevant in 2026 if you're rescuing legacy code), and the pure helpers (check-attr, check-ignore, credential, hook).

A lot of these commands you'll use rarely. That's fine. The point of knowing them isn't to use them daily — it's so you recognize the right tool when the situation calls for it. When your repo's blowing up to 12 GB, you should know that count-objects -v and repack -ad exist before you start googling. When git filter-branch lights up in a Stack Overflow answer, you should know it's been deprecated for years and git filter-repo is the right answer.

Some modules in this tier are deliberately short. git mailinfo doesn't need a page-long explanation; it parses an email and you'll never call it directly. The 12-section template still applies, but a section may collapse to one sentence. That's by design. The full layout means you always know where to look.

📚 Modules in this tier (58)

M00○
Tier 2 intro — start here
Mindset, prerequisites, what you'll know by the end.
M01○
git config
Layered config: system, global, local, worktree. Learn the layers.
M02○
git fast-export
Half of repo-to-repo migration. Pairs with fast-import.
M03○
git fast-import
How most VCS-import tools (svn, hg, bzr) get into Git.
M04○
git filter-branch
Don't. Use git filter-repo. Listed for completeness.
M05○
git mergetool
Hands conflicts to vimdiff/meld/kdiff3/etc.
M06○
git pack-refs
Turns hundreds of loose ref files into one. fsck-friendly.
M07○
git prune
Usually invoked indirectly by gc.
M08○
git reflog
Your safety net. Almost everything you 'lost' is in here.
M09○
git refs
Switching from files to reftable, etc. Plumbing-adjacent.
M10○
git remote
Add, rename, prune, set URLs.
M11○
git repack
Loose objects in, packfiles out.
M12○
git replace
Local-only object aliasing. Niche, occasionally lifesaving.
M13○
git annotate
POSIX-style output. Still works.
M14○
git blame
Who broke this and when. Be kind in the comments.
M15○
git bugreport
Dumps environment, version, config — for filing bugs upstream.
M16○
git count-objects
Loose objects, packs, sizes. Quick health check.
M17○
git diagnose
Newer than bugreport. More artifacts.
M18○
git difftool
Hands diffs to meld/vimdiff/etc.
M19○
git fsck
Find dangling and broken objects.
M20○
git help
git help <cmd>, or git <cmd> --help. Read the manuals.
M21○
git instaweb
Browse your repo locally on 127.0.0.1.
M22○
git merge-tree
What would happen if I merged X into Y? Without touching either.
M23○
git rerere
Re-Recorded Resolution. Conflict autopilot — once you opt in.
M24○
git show-branch
An ancient ASCII multi-branch viewer. Sometimes still the right tool.
M25○
git verify-commit
Validates signed commits.
M26○
git verify-tag
Validates signed tags. Releases love these.
M27○
git version
Sometimes the answer is 'upgrade'.
M28○
git whatchanged
Like git log --raw with a different default. Mostly historical.
M29○
gitweb
Web frontend that ships with Git. Old. Still works.
M30○
git archimport
If you still have any of these, this is how you escape.
M31○
git cvsexportcommit
One-way bridge for the holdouts.
M32○
git cvsimport
Migration tool for the historical.
M33○
git cvsserver
Pretend to be CVS so old clients can pull.
M34○
git imap-send
Stage email-patches in your drafts folder.
M35○
git p4
A real-world coexistence tool when you can't migrate yet.
M36○
git quiltimport
Old kernel/userspace workflow ingestion.
M37○
git request-pull
The pre-Github-PR way to ask for a merge.
M38○
git send-email
format-patch + sendmail in one. Still the kernel's workflow.
M39○
git svn
Workable if your team is mostly on Git but origin is svn.
M40○
git check-attr
Why is this file being treated like text? This tells you.
M41○
git check-ignore
Tells you which .gitignore rule matched.
M42○
git check-mailmap
Apply .mailmap to a name to see the canonical form.
M43○
git check-ref-format
Is 'feature/$thing' a legal branch name? Ask this.
M44○
git column
Internal formatter. Used by ls-files and friends.
M45○
git credential
Used internally to fetch and store creds.
M46○
git credential-cache
Caches creds for a few minutes.
M47○
git credential-store
Writes creds in cleartext. Convenient. Insecure. Know the trade.
M48○
git fmt-merge-msg
Used by git merge to compose its commit message.
M49○
git hook
Small porcelain over the .git/hooks dir.
M50○
git interpret-trailers
The Co-authored-by:/Signed-off-by: handler.
M51○
git mailinfo
Used by git am internally.
M52○
git mailsplit
Pre-step for git am on a big mailbox.
M53○
git merge-one-file
What .gitattributes merge=union etc. dispatches to.
M54○
git patch-id
Same change, different commit IDs — patch-id matches them up.
M55○
git sh-i18n
Internationalization plumbing for shell-based commands.
M56○
git sh-setup
Sourced by Git's shell-script subcommands.
M57○
git stripspace
Used by hooks and editors to tidy commit messages.