Viewing commit history with git log - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the command git log do?

It shows the list of commits made in the current branch, displaying details like commit ID, author, date, and message.

beginner

How can you view a simplified one-line summary of each commit using git log?

Use git log --oneline to see each commit as a single line with a short commit ID and the commit message.

intermediate

What option would you add to git log to see the changes made in each commit?

Add -p to git log to show the patch (diff) introduced by each commit.

beginner

How do you limit the number of commits shown by git log?

Use git log -n <number> to show only the last <number> commits. For example, git log -n 3 shows the last 3 commits.

intermediate

What does the --graph option do when used with git log?

It shows a text-based graph of the branch structure and commit history, helping visualize merges and branches.

Which command shows a simple one-line summary of each commit?

A git log -p

B git log --oneline

C git status

D git diff

git log --oneline shows each commit in a short, one-line format.

How do you see the detailed changes introduced by each commit?

A git log -p

B git log --oneline

C git show

D git diff HEAD

git log -p shows the patch (diff) for each commit in the log.

What does git log -n 5 do?

A Shows commits with 5 files changed

B Shows commits from 5 days ago

C Shows commits with 5 authors

D Shows the last 5 commits

The -n option limits the number of commits shown to the specified number.

Which option adds a visual graph of branches to the commit history?

A --stat

B --oneline

C --graph

D -p

--graph draws a text-based graph showing branch and merge history.

What information is NOT shown by default in git log?

A Files changed in the commit

B Author name

C Date of commit

D Commit message

By default, git log does not show files changed; use -p or --stat for that.

Explain how to use git log to view a simple list of recent commits with short IDs and messages.

Think about a command that makes the log easier to read quickly.

Describe how to see the actual changes made in each commit using git commands.

Look for an option that shows differences inside the log.

Practice

1. What does the git log command do in a Git repository?

easy

A. Deletes the last commit from the repository

B. Shows the history of commits made in the repository

C. Creates a new branch in the repository

D. Displays the current status of files in the repository

Solution

1. Step 1: Understand the purpose of git log

   The git log command is used to view the commit history in a Git repository.

2. Step 2: Compare with other Git commands

   Other commands like git status show file status, and git branch manages branches, but git log specifically shows commits.

3. Final Answer:

   Shows the history of commits made in the repository -> Option B

4. Quick Check:

   git log = commit history [OK]

Hint: Remember: log means history or record [OK]

Common Mistakes:

• Confusing git log with git status
• Thinking git log deletes commits
• Mixing git log with branch creation

2. Which of the following is the correct command to show a simplified one-line summary of each commit in Git?

easy

A. git log --oneline

B. git log --summary

C. git log --details

D. git log --short

Solution

1. Step 1: Identify the option for one-line commit summary

   The --oneline option condenses each commit to a single line showing the commit hash and message.

2. Step 2: Verify other options

   Options like --summary, --details, and --short are not valid git log options for this purpose.

3. Final Answer:

   git log --oneline -> Option A

4. Quick Check:

   --oneline = short commit list [OK]

Hint: Use --oneline for brief commit history [OK]

Common Mistakes:

• Using non-existent options like --summary
• Confusing --oneline with --short
• Forgetting the double dash before options

3. Given the command git log -2 --oneline, what will be the output?

medium

A. Shows the last two commits in a detailed multi-line format

B. Shows all commits except the last two

C. Shows the last two commits each summarized in one line

D. Shows the first two commits in the repository

Solution

1. Step 1: Understand the -2 option

   The -2 option limits the output to the last two commits only.

2. Step 2: Understand the --oneline option

   The --oneline option shows each commit in a single line summary.

3. Final Answer:

   Shows the last two commits each summarized in one line -> Option C

4. Quick Check:

   -2 + --oneline = last two commits short [OK]

Hint: Combine -n with --oneline for short recent commits [OK]

Common Mistakes:

• Thinking -2 shows first two commits
• Expecting detailed multi-line output with --oneline
• Confusing exclusion of commits with limiting output

4. You ran git log --oneline -p but got an error. What is the likely cause?

medium

A. The options --oneline and -p cannot be used together

B. You need to specify a branch name with the command

C. You must run git fetch before using git log

D. The repository has no commits yet

Solution

1. Step 1: Understand the options --oneline and -p

   --oneline shows a brief summary, while -p shows patch (diff) details.

2. Step 2: Check compatibility of options

   These two options conflict because one shows a short summary and the other shows detailed changes, so Git throws an error.

3. Final Answer:

   The options --oneline and -p cannot be used together -> Option A

4. Quick Check:

   --oneline + -p conflict = error [OK]

Hint: Avoid combining --oneline with -p; they conflict [OK]

Common Mistakes:

• Assuming branch name is required for git log
• Thinking git fetch fixes git log errors
• Ignoring that empty repo causes no output, not error

5. You want to see the commit history with each commit showing the author, date, and a one-line message, all in a compact format. Which command should you use?

hard

A. git log --graph --decorate

B. git log --oneline --author-date-order

C. git log -p --stat

D. git log --pretty=format:"%h - %an, %ar : %s"

Solution

1. Step 1: Understand the requirement for custom format

   You want author, date, and message in one line, so a custom format with --pretty=format: is needed.

2. Step 2: Analyze the format string

   %h is short commit hash, %an is author name, %ar is relative date, and %s is commit message. This matches the requirement.

3. Step 3: Check other options

   --oneline --author-date-order does not show author or date explicitly. -p --stat shows diffs and stats, not compact. --graph --decorate shows branch graph and refs, not author/date/message in one line.

4. Final Answer:

   git log --pretty=format:"%h - %an, %ar : %s" -> Option D

5. Quick Check:

   Custom format = author, date, message [OK]

Hint: Use --pretty=format for custom commit info display [OK]

Common Mistakes:

• Using --oneline without author or date info
• Expecting -p to show summary info
• Confusing --graph with formatting output