Searching history with git log -S - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the -S option do in git log?

The -S option searches for commits that add or remove a specific string in the code. It helps find changes related to that exact text.

intermediate

How is git log -S different from git log -G?

-S searches for changes in the number of occurrences of a string, while -G searches for commits that match a regular expression pattern in the diff.

beginner

Write a command to find commits that added or removed the word 'bugfix' in the project history.

git log -S'bugfix'

intermediate

Can git log -S search for changes in binary files?

No, git log -S works only with text changes. It cannot search inside binary files.

beginner

Why might git log -S be useful when debugging?

It helps find exactly when a specific piece of code was added or removed, making it easier to track down when a bug was introduced or fixed.

What does git log -S'functionName' do?

A Shows commits that contain 'functionName' anywhere

B Shows commits that deleted 'functionName' only

C Shows commits that changed the file named 'functionName'

D Shows commits that added or removed 'functionName'

-S finds commits where the number of occurrences of the string changes, so it shows commits that added or removed 'functionName'.

Which option would you use to search commits by a regular expression pattern?

A -p

B -S

C -G

D -a

-G searches commits by matching a regex pattern in the diff.

If you want to find when a variable name was changed, which command helps best?

A git log -S'variableName'

B git log --oneline

C git status

D git diff

git log -S finds commits that added or removed the variable name.

Does git log -S show commits that only mention the string in commit messages?

A Yes, it searches commit messages

B No, it searches code changes only

C Yes, but only for merge commits

D No, it searches file names only

-S searches for changes in the code, not commit messages.

What is a practical use of git log -S?

A To find when a specific code line was added or removed

B To list all branches

C To merge two branches

D To clone a repository

git log -S helps find commits that changed a specific string in the code.

Explain how git log -S helps you find when a specific piece of code was added or removed.

Think about how you find when a word first appeared or disappeared in your project.

Describe the difference between git log -S and git log -G.

One looks for exact string changes, the other for pattern matches.

Practice

1. What does the git log -S command do?

easy

A. Finds commits that added or removed a specific string in the code.

B. Shows the current status of files in the working directory.

C. Displays the list of branches in the repository.

D. Creates a new branch with the given name.

Solution

1. Step 1: Understand the purpose of git log -S

   This command searches commit history for changes that added or removed a specific string.

2. Step 2: Compare with other git commands

   Other options like git status show file status, git branch lists branches, and git branch <name> creates branches, which are different tasks.

3. Final Answer:

   Finds commits that added or removed a specific string in the code. -> Option A

4. Quick Check:

   Search commits by string change = B [OK]

Hint: Remember: -S searches for string changes in commits [OK]

Common Mistakes:

• Confusing -S with showing file status
• Thinking it lists branches
• Assuming it creates branches

2. Which of the following is the correct syntax to find commits that added or removed the word fix using git log -S?

easy

A. git log -S fix

B. git log -s fix

C. git log --search=fix

D. git log -search fix

Solution

1. Step 1: Identify correct option flag

   The correct flag to search for string changes is uppercase -S, so git log -S fix is correct.

2. Step 2: Check other options for syntax errors

   -s is not valid for this purpose, and --search or -search are not valid git log options.

3. Final Answer:

   git log -S fix -> Option A

4. Quick Check:

   Uppercase -S for string search = A [OK]

Hint: Use uppercase -S to search string changes in git log [OK]

Common Mistakes:

• Using lowercase -s instead of -S
• Trying non-existent --search option
• Adding extra dashes incorrectly

3. Given the following git log command:
git log -S 'bugfix' --oneline
What will this command output?

medium

A. An error because the string 'bugfix' is not quoted correctly.

B. A list of all commits with the word 'bugfix' anywhere in the commit message.

C. A list of commits that modified files named 'bugfix'.

D. A list of commits that added or removed the string 'bugfix', shown in one line each.

Solution

1. Step 1: Understand -S 'bugfix' usage

   This searches commits that added or removed the exact string 'bugfix' in the code or content.

2. Step 2: Understand --oneline option

   This shows each commit in a short single line format for easy reading.

3. Final Answer:

   A list of commits that added or removed the string 'bugfix', shown in one line each. -> Option D

4. Quick Check:

   -S finds string changes, --oneline shortens output = D [OK]

Hint: Combine -S with --oneline for short commit list by string [OK]

Common Mistakes:

• Thinking it searches commit messages instead of code changes
• Assuming it filters by file names
• Believing quotes cause errors here

4. You run git log -S 'update' but get no results, even though you know the word 'update' was added in some commits. What could be the problem?

medium

A. You need to use git log -G 'update' to search commit messages.

B. You forgot to put quotes around the search string.

C. The string 'update' was only changed in commit messages, not in code.

D. The repository has no commits at all.

Solution

1. Step 1: Understand what -S searches

   -S searches for string changes in the code or content, not in commit messages.

2. Step 2: Consider commit message search

   If 'update' was only added or changed in commit messages, -S won't find it; use git log --grep 'update' to search commit messages. -G searches code diffs by regex.

3. Final Answer:

   The string 'update' was only changed in commit messages, not in code. -> Option C

4. Quick Check:

   -S searches code changes, not commit messages = A [OK]

Hint: Use -G to search commit messages, -S for code changes [OK]

Common Mistakes:

• Assuming -S searches commit messages
• Thinking quotes cause no results
• Believing repository is empty without checking

5. You want to find all commits that added or removed the string TODO but only in the src/ folder. Which command will do this correctly?

hard

A. git log -S 'TODO' --path src/

B. git log -S 'TODO' -- src/

C. git log -S 'TODO' src/

D. git log --S 'TODO' -- src/

Solution

1. Step 1: Use -S 'TODO' to search string changes

   This finds commits adding or removing 'TODO'.

2. Step 2: Use -- src/ to limit search to the src folder

   The double dash -- separates options from path arguments, so -- src/ limits the search to that folder.

3. Step 3: Check other options for syntax correctness

   src/ alone without -- is invalid here; --path is not a git log option; --S is invalid (uppercase S must be after git log).

4. Final Answer:

   git log -S 'TODO' -- src/ -> Option B

5. Quick Check:

   Use -- before path to limit git log search = C [OK]

Hint: Use -- before folder path to limit git log search [OK]

Common Mistakes:

• Omitting -- before path
• Using invalid --path option
• Writing --S instead of -S