World 2: Undo Magic

Reflog, your safety net

You will learn: how to find and bring back "lost" commits.

The problem

Oops. You typed git reset --hard HEAD~1. Your day 3 entry vanished. Panic?

Watch

~/diary $ git reflogbcf4670 (HEAD -> main) HEAD@{0}: reset: moving to HEAD~1031ae57 HEAD@{1}: commit: Add day 3 entrybcf4670 (HEAD -> main) HEAD@{2}: commit: Add day 2 entry270a76e HEAD@{3}: commit: Add stylea8feb63 HEAD@{4}: commit: Add day 1 page6d3a9b1 HEAD@{5}: commit (initial): Add README

No panic. Git keeps a diary of every place HEAD has been. This is the . Your lost commit is still listed.

Try it

Find your lost commit in the reflog.

Tap the line with Add day 3 entry.

~/diary $ git reflog

0 of 1 found

Watch

~/diary $ git reflog -n 2bcf4670 (HEAD -> main) HEAD@{0}: reset: moving to HEAD~1031ae57 HEAD@{1}: commit: Add day 3 entry

HEAD@{1} means “where HEAD was one move ago”. You can use that name in commands.

Try it

Bring the day 3 commit back.

Hint

Type git reset --hard HEAD@{1}, then press Enter.

Predict

What can the reflog bring back?

You did it!

You can now bring back “lost” commits with the reflog.

Go deeper (optional)

The reflog lives only on your computer. It is never pushed. Old lines expire, after 90 days by default. Lines for lost commits go after 30. You can also reset to a hash from the reflog list.

~/diary $ git reset --hard HEAD@{1}HEAD is now at 031ae57 Add day 3 entry~/diary $ git log --oneline031ae57 (HEAD -> main) Add day 3 entrybcf4670 Add day 2 entry270a76e Add stylea8feb63 Add day 1 page6d3a9b1 Add README