Interactive rebase (git rebase -i) - Commands & Configuration

Introduction

Sometimes you want to clean up your commit history before sharing your work. Interactive rebase lets you change, combine, or reorder commits easily.

When you want to combine several small commits into one clear commit before pushing.

When you need to fix a typo or mistake in an earlier commit message.

When you want to reorder commits to make the history easier to understand.

When you want to remove unnecessary commits from your branch.

When you want to split a big commit into smaller logical commits.

Commands

Shows the last 5 commits in short form so you can decide which commits to edit or reorder.

Terminal

git log --oneline -5

Expected Output

a1b2c3d Fix typo in README

b2c3d4e Add user login feature

c3d4e5f Update styles for homepage

d4e5f6a Improve error handling

e5f6a7b Initial commit

→

--oneline - Shows each commit in one line for easy reading

→

-5 - Limits output to last 5 commits

Starts an interactive rebase for the last 3 commits so you can edit, reorder, or squash them.

Terminal

git rebase -i HEAD~3

Expected Output

pick c3d4e5f Update styles for homepage

pick d4e5f6a Improve error handling

pick e5f6a7b Add user login feature



# Rebase a1b2c3d..e5f6a7b onto a1b2c3d (3 commands)

#

# Commands:

# p, pick = use commit

# r, reword = use commit, but edit the commit message

# e, edit = use commit, but stop for amending

# s, squash = use commit, but meld into previous commit

# f, fixup = like "squash", but discard this commit's log message

# x, exec = run command (the rest of the line) using shell

# d, drop = remove commit

#

# These lines can be re-ordered; they are executed from top to bottom.

→

-i - Starts interactive mode

→

HEAD~3 - Specifies the last 3 commits to rebase

Shows the last 3 commits after rebase to verify changes.

Terminal

git log --oneline -3

Expected Output

f7g8h9i Update styles and improve error handling

j8k9l0m Add user login feature

m1n2o3p Initial commit

→

--oneline - Shows commits in one line

→

-3 - Limits output to last 3 commits

Key Concept

If you remember nothing else from interactive rebase, remember: it lets you rewrite your recent commit history safely to make it cleaner and clearer before sharing.

Common Mistakes

Trying to rebase commits that have already been pushed to a shared repository.

This can cause conflicts and confusion for others who have the old history.

Only use interactive rebase on local commits that have not been pushed yet.

Not saving and closing the editor properly during the interactive rebase.

The rebase will not start or will be aborted if the editor is not closed correctly.

Make sure to save changes and exit the editor (e.g., :wq in vim) to continue.

Using the wrong number after HEAD~ to select commits.

You might rebase too many or too few commits, causing unexpected changes.

Count commits carefully and use HEAD~N where N is the exact number of commits you want to edit.

Summary

Use 'git rebase -i HEAD~N' to start editing the last N commits interactively.

In the editor, you can reorder, squash, edit, or drop commits to clean history.

Always verify your commit history after rebase with 'git log --oneline'.

Practice

1. What is the main purpose of using git rebase -i (interactive rebase)?

easy

A. To reorder, edit, or combine recent commits before sharing

B. To create a new branch from the current commit

C. To permanently delete the entire commit history

D. To push commits directly to the remote repository

Solution

1. Step 1: Understand the purpose of interactive rebase

   Interactive rebase allows you to change the order, combine, edit, or remove recent commits.

2. Step 2: Compare with other git commands

   Creating branches, deleting history, or pushing commits are different git operations.

3. Final Answer:

   To reorder, edit, or combine recent commits before sharing -> Option A

4. Quick Check:

   Interactive rebase = reorder/edit commits [OK]

Hint: Interactive rebase = rewrite recent commits easily [OK]

Common Mistakes:

• Confusing rebase with branch creation
• Thinking it deletes all history
• Assuming it pushes commits automatically

2. Which of the following is the correct command to start an interactive rebase for the last 3 commits?

easy

A. git rebase -i HEAD^^3

B. git rebase -i HEAD~3

C. git rebase -i HEAD~

D. git rebase -i HEAD^3

Solution

1. Step 1: Recall the syntax for interactive rebase

   The correct syntax uses HEAD~N to specify the last N commits, so HEAD~3 means last 3 commits.

2. Step 2: Check the options

   HEAD^3 and HEAD^^3 are invalid for this purpose; HEAD~ alone is incomplete.

3. Final Answer:

   git rebase -i HEAD~3 -> Option B

4. Quick Check:

   HEAD~3 selects last 3 commits [OK]

Hint: Use HEAD~N to select last N commits for rebase [OK]

Common Mistakes:

• Using HEAD^3 instead of HEAD~3
• Omitting the number after ~
• Using double carets ^^ incorrectly

3. Given the following interactive rebase todo list:

pick a1b2c3 Commit A
pick d4e5f6 Commit B
pick 789abc Commit C

If you change it to:

pick d4e5f6 Commit B
squash 789abc Commit C
pick a1b2c3 Commit A

What will happen after completing the rebase?

medium

A. Only Commit C will be applied, others dropped

B. Commits A and B will be combined, Commit C will be last

C. The rebase will fail due to invalid order

D. Commits B and C will be combined, and Commit A will be last

Solution

1. Step 1: Understand 'pick' and 'squash' in rebase

   'pick' applies a commit as is; 'squash' combines the commit with the previous one.

2. Step 2: Analyze the new order

   Commit B is picked first, Commit C is squashed into B, Commit A is picked last.

3. Final Answer:

   Commits B and C will be combined, and Commit A will be last -> Option D

4. Quick Check:

   squash merges commits; order changed [OK]

Hint: Squash merges commit into previous one in order [OK]

Common Mistakes:

• Thinking squash drops commits
• Assuming order stays same after rebase
• Confusing squash with fixup

4. You run git rebase -i HEAD~2 and change the second commit's action from pick to edit. After saving, what should you do next to modify that commit?

medium

A. Make changes, then run git commit --amend and git rebase --continue

B. Run git push immediately to update remote

C. Abort the rebase with git rebase --abort

D. Run git reset --hard HEAD~1 to undo the commit

Solution

1. Step 1: Understand 'edit' in interactive rebase

   When a commit is marked 'edit', rebase pauses to let you change it.

2. Step 2: Modify commit and continue rebase

   You make changes, amend the commit with git commit --amend, then continue with git rebase --continue.

3. Final Answer:

   Make changes, then run git commit --amend and git rebase --continue -> Option A

4. Quick Check:

   Edit = amend commit + continue rebase [OK]

Hint: Edit commit: amend changes, then continue rebase [OK]

Common Mistakes:

• Pushing before finishing rebase
• Aborting instead of continuing
• Resetting commits incorrectly

5. You want to clean up your last 4 commits by combining the second and third commits into one, and also reorder commits so the last commit becomes the first. Which interactive rebase todo list correctly achieves this?

pick 111aaa Commit 1
pick 222bbb Commit 2
pick 333ccc Commit 3
pick 444ddd Commit 4

hard

A. pick 444ddd Commit 4
squash 222bbb Commit 2
pick 333ccc Commit 3
pick 111aaa Commit 1

B. pick 444ddd Commit 4
pick 111aaa Commit 1
squash 222bbb Commit 2
pick 333ccc Commit 3

C. pick 444ddd Commit 4
pick 111aaa Commit 1
pick 222bbb Commit 2
squash 333ccc Commit 3

D. pick 111aaa Commit 1
pick 333ccc Commit 3
squash 222bbb Commit 2
pick 444ddd Commit 4

Solution

1. Step 1: Reorder commits to put last commit first

   Commit 4 (444ddd) should be first in the list to reorder it first.

2. Step 2: Combine second and third commits

   To combine commits 2 and 3, use 'pick' on commit 2 and 'squash' on commit 3 immediately after.

3. Step 3: Verify the todo list

   pick 444ddd Commit 4
   pick 111aaa Commit 1
   pick 222bbb Commit 2
   squash 333ccc Commit 3

   places commit 4 first, then commit 1, then picks commit 2 and squashes commit 3, matching requirements.

4. Final Answer:

   pick 444ddd Commit 4
   pick 111aaa Commit 1
   pick 222bbb Commit 2
   squash 333ccc Commit 3

   -> Option C

5. Quick Check:

   Reorder + squash =

   pick 444ddd Commit 4
   pick 111aaa Commit 1
   pick 222bbb Commit 2
   squash 333ccc Commit 3

   [OK]

Hint: Put last commit first, squash 3rd into 2nd commit [OK]

Common Mistakes:

• Squashing commits in wrong order
• Not moving last commit to first position
• Using squash on wrong commits