Reflog for finding lost commits in Git - Commands & Configuration

Introduction

Sometimes you lose track of commits after changes like resets or branch switches. Git reflog helps you find those lost commits by showing a history of where your branches and HEAD have pointed.

When you accidentally reset your branch and want to recover previous commits.

When you switched branches and lost track of recent commits.

When you deleted a branch but want to find commits that were on it.

When you want to see a timeline of all recent changes to HEAD.

When you want to undo a recent commit or reset by finding its reference.

Commands

This command shows a list of recent positions of HEAD, including commits, resets, and checkouts. It helps you find lost commits by showing their references.

Terminal

git reflog

Expected Output

a1b2c3d (HEAD -> main) HEAD@{0}: commit: Fix typo in README

f4e5d6c HEAD@{1}: reset: moving to f4e5d6c

123abcd HEAD@{2}: commit: Add user login feature

789ef01 HEAD@{3}: checkout: moving from feature to main

This command switches your working directory to the commit found in reflog, allowing you to inspect or recover lost work.

Terminal

git checkout a1b2c3d

Expected Output

Note: switching to 'a1b2c3d'.



You are in 'detached HEAD' state. You can look around, make experimental changes and commit them, and you can discard any commits you make in this state without impacting any branches.



HEAD is now at a1b2c3d Fix typo in README

This creates a new branch at the current commit so you can keep the recovered commit safe and continue working from it.

Terminal

git branch recovered-branch

Expected Output

No output (command runs silently)

Switch to the new branch to continue work from the recovered commit.

Terminal

git checkout recovered-branch

Expected Output

Switched to branch 'recovered-branch'

Key Concept

If you lose commits, git reflog shows where HEAD and branches pointed recently so you can find and recover them.

Common Mistakes

Trying to find lost commits using only 'git log' without reflog.

'git log' shows commits reachable from current branches, but lost commits after resets or checkouts may not appear.

Use 'git reflog' to see all recent HEAD positions including lost commits.

Not creating a branch after checking out a lost commit.

If you stay in detached HEAD state and make changes, you risk losing them if you switch branches.

Create a new branch at the recovered commit to save your work.

Summary

Use 'git reflog' to see recent HEAD movements and find lost commits.

Checkout the commit hash from reflog to inspect lost commits.

Create a new branch at the recovered commit to save and continue work.

Practice

1. What is the primary purpose of git reflog?

easy

A. To list all remote branches

B. To permanently delete commits from the repository

C. To record where HEAD and branches have pointed recently

D. To merge two branches automatically

Solution

1. Step 1: Understand what reflog tracks

   Reflog records the history of where HEAD and branch references have pointed, including commits that might be lost after resets or rebases.

2. Step 2: Compare options with reflog purpose

   Only To record where HEAD and branches have pointed recently correctly describes reflog's role. Options B, C, and D describe unrelated git functions.

3. Final Answer:

   To record where HEAD and branches have pointed recently -> Option C

4. Quick Check:

   Reflog tracks HEAD history = A [OK]

Hint: Reflog shows recent HEAD moves, like a safety net [OK]

Common Mistakes:

• Confusing reflog with git log
• Thinking reflog deletes commits
• Assuming reflog lists remote branches

2. Which command correctly shows the reflog entries?

easy

A. git reflog

B. git reflog list

C. git reflog -a

D. git reflog --show

Solution

1. Step 1: Recall the basic reflog command

   The simplest and correct command to show reflog entries is git reflog.

2. Step 2: Evaluate other options

   git reflog --show is invalid; git reflog list and git reflog -a are invalid commands.

3. Final Answer:

   git reflog -> Option A

4. Quick Check:

   Basic reflog command = git reflog [OK]

Hint: Use just 'git reflog' to see recent HEAD moves [OK]

Common Mistakes:

• Adding unnecessary subcommands like 'list'
• Using invalid flags like '-a'
• Confusing reflog with git log

3. After running git reset --hard HEAD~1, you realize you lost a commit. Which command helps you find the lost commit's hash?

medium

A. git reflog

B. git status

C. git branch

D. git log --oneline

Solution

1. Step 1: Understand what happens after reset

   git reset --hard HEAD~1 moves HEAD back one commit, making the latest commit unreachable but still in reflog.

2. Step 2: Identify command to find lost commit

   git reflog shows recent HEAD positions including the lost commit's hash. Other commands won't show unreachable commits.

3. Final Answer:

   git reflog -> Option A

4. Quick Check:

   Reflog shows lost commits after reset = C [OK]

Hint: Use reflog to find commits lost by reset [OK]

Common Mistakes:

• Using git status which shows working tree only
• Using git branch which lists branches, not commits
• Using git log which hides unreachable commits

4. You ran git reset --hard HEAD~2 but want to restore the latest commit. Which command correctly resets to the lost commit using reflog?

medium

A. git reset --hard HEAD@{2}

B. git reset --hard origin/main

C. git reset --hard HEAD~1

D. git reset --hard HEAD@{1}

Solution

1. Step 1: Understand reflog indexing

   After resetting HEAD back two commits, reflog entries show HEAD@{0} as current, HEAD@{1} as previous position (the lost commit), and HEAD@{2} as older.

2. Step 2: Choose correct reflog entry to restore

   To restore the latest lost commit, reset to HEAD@{1} which points to it. HEAD@{2} is older, HEAD~1 is relative to current HEAD, and origin/main may differ.

3. Final Answer:

   git reset --hard HEAD@{1} -> Option D

4. Quick Check:

   Use HEAD@{1} to restore last HEAD position [OK]

Hint: Reset to HEAD@{1} to undo last reset [OK]

Common Mistakes:

• Using HEAD@{2} which is older than needed
• Using HEAD~1 which is relative to current HEAD
• Resetting to origin/main which may differ

5. You accidentally deleted a branch with important commits. How can you recover the lost commits using reflog?

hard

A. Run git branch -d to restore the branch

B. Find the commit hash in git reflog and create a new branch at that hash

C. Use git reset --hard origin/branch-name to recover commits

D. Re-clone the repository to get the branch back

Solution

1. Step 1: Locate lost commits in reflog

   Deleted branch commits remain in reflog as recent HEAD positions or branch references before deletion.

2. Step 2: Create a new branch at the lost commit hash

   After finding the commit hash in reflog, use git branch new-branch-name <commit-hash> to restore the branch with lost commits.

3. Final Answer:

   Find the commit hash in git reflog and create a new branch at that hash -> Option B

4. Quick Check:

   Reflog + new branch recovers deleted commits [OK]

Hint: Use reflog hash to recreate deleted branch [OK]

Common Mistakes:

• Trying to delete branch again to restore it
• Resetting to origin which may not have deleted commits
• Re-cloning loses local lost commits