Searching history with git log -S - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What does the command git log -S'fixBug' do?

Consider the command git log -S'fixBug'. What is the output or effect of running this command in a git repository?

Git

git log -S'fixBug'

A Displays commits that modified files named 'fixBug'.

B Shows commits that added or removed the string 'fixBug' anywhere in the code.

C Lists commits that contain the word 'fixBug' in their commit message only.

D Searches for commits that changed the author name to 'fixBug'.

💡 Hint

Think about what the -S option searches for in the commit history.

The -S option in git log searches for commits where the specified string was added or removed in the code changes, not just in messages or filenames.

✅ Best Practice

intermediate

Which command helps find commits that introduced or removed a function named calculateSum?

You want to find commits where the function calculateSum was added or removed in your code. Which git command is best suited for this?

A git log -S'calculateSum'

B git log --grep='calculateSum'

C git log --author='calculateSum'

D git log --name-only | grep 'calculateSum'

💡 Hint

Remember, -S searches code changes, while --grep searches commit messages.

git log -S'calculateSum' searches commits that added or removed the string 'calculateSum' in the code, which is what you want.

❓ Troubleshoot

advanced

Why does git log -S'init' show no commits even though the string exists in the code?

You run git log -S'init' but it returns no commits, even though the string 'init' is present in your current code files. What is the most likely reason?

A The string 'init' was never added or removed in any commit; it was always present.

B The repository is corrupted and cannot search history.

C The command requires <code>--all</code> to search all branches.

D The string 'init' is too short and ignored by git log.

💡 Hint

Think about what -S actually searches for in commits.

-S finds commits where the string was added or removed. If 'init' was never changed but always present, no commits will match.

🧠 Conceptual

advanced

What is the difference between git log -S and git log -G?

Both git log -S and git log -G search commit history. What is the key difference between them?

A <code>-S</code> searches author names; <code>-G</code> searches file names.

B <code>-S</code> searches commit messages; <code>-G</code> searches code changes.

C <code>-S</code> searches only the latest commit; <code>-G</code> searches all commits.

D <code>-S</code> searches for changes in the number of occurrences of a string; <code>-G</code> searches for commits matching a regex pattern.

💡 Hint

Consider how -S and -G treat the search string.

-S looks for commits where the count of a string changes (added or removed). -G looks for commits where the diff matches a regex pattern.

🔀 Workflow

expert

How to find the first commit that introduced the string TODO using git log -S?

You want to find the very first commit in your repository history that introduced the string TODO. Which sequence of commands or options will help you achieve this?

A git log -S'TODO' --reverse

B git log -S'TODO' --reverse --ancestry-path --all

C git log -S'TODO' --all --reverse --max-count=1

D git log -S'TODO' --max-count=1

💡 Hint

Think about how to reverse the order and limit results to find the first commit.

Using --all searches all refs, --reverse shows commits from oldest to newest, and --max-count=1 limits output to the first match, which is the first commit that introduced 'TODO'.