git log

git log --oneline

git log --oneline --graph

git log --oneline --graph --all

git log --oneline --graph --all --decorate

git log --oneline --graph --all --decorate

# Show the latest commit with its patch
git show
 
# Show a specific commit
git show abc1234
 
# Show without the diff (metadata only)
git show --no-patch abc1234
git show -s abc1234
 
# Show with stat summary instead of full diff
git show --stat abc1234

git log --format=short -3
git log --format=full -3
git log --format=fuller -3

git log --pretty=format:"%h %s (%an, %ar)"

git log --pretty=format:"%C(yellow)%h%C(reset) %C(blue)%an%C(reset) %s %C(green)(%ar)%C(reset)%C(red)%d%C(reset)"

git log --pretty=format:"- %s (%an)" v1.0..v2.0

git log --pretty=format:"%h | %ai | %-20an | %s"

git log --pretty=format:'{"hash":"%H","author":"%an","date":"%ai","message":"%s"},'

# Commits by a specific author (substring match, case-insensitive)
git log --author="Alice"
 
# Combine with oneline for scanning
git log --oneline --author="alice@example.com"
 
# Multiple authors (OR logic)
git log --oneline --author="Alice\|Bob"

# Relative dates
git log --since="2 weeks ago"
git log --since="3 days"
git log --until="1 month ago"
 
# Absolute dates
git log --since="2024-01-01"
git log --until="2024-06-30"
 
# Combined range
git log --since="2024-01-01" --until="2024-03-31"
 
# Natural language
git log --since="last Monday"
git log --since="yesterday"

# Alice's commits from the last month
git log --oneline --author="Alice" --since="1 month ago"
 
# Bob's commits between two dates
git log --oneline --author="Bob" --since="2024-01-01" --until="2024-03-31"

# Find commits mentioning "login"
git log --oneline --grep="login"
 
# Case-insensitive search
git log --oneline --grep="login" -i
 
# Regex patterns
git log --oneline --grep="fix\|bug\|patch"
 
# All branches
git log --oneline --grep="login" --all
 
# Invert match (commits NOT mentioning "WIP")
git log --oneline --grep="WIP" --invert-grep

# Commits mentioning "login" OR "auth"
git log --grep="login" --grep="auth"
 
# Commits mentioning "login" AND "auth" (both in the message)
git log --grep="login" --grep="auth" --all-match

# Find commits where "validateEmail" was added or removed
git log -S "validateEmail" --oneline
 
# With the actual diff
git log -S "validateEmail" -p
 
# Restrict to specific file types
git log -S "validateEmail" --oneline -- "*.js"

# Find commits where lines matching a regex were changed
git log -G "function\s+validate" --oneline
 
# Find TODO additions/removals
git log -G "TODO|FIXME" --oneline -p

# Commits that modified a specific file
git log --oneline -- src/auth.js
 
# Commits that touched anything in a directory
git log --oneline -- src/components/
 
# Multiple paths
git log --oneline -- src/auth.js src/config.js
 
# Glob patterns
git log --oneline -- "*.test.js"
 
# Follow renames (for a single file)
git log --oneline --follow -- src/auth.js

git log --oneline --follow -- src/utils/helpers.js
# Shows commits even from when it was called src/helpers.js

# History of lines 10-20 in auth.js
git log -L 10,20:src/auth.js
 
# History of a function (Git auto-detects function boundaries)
git log -L :validateEmail:src/auth.js
 
# From a line to end of function
git log -L 15,+10:src/auth.js

git log --oneline main..feature

git log --oneline main...feature

git log --oneline --left-right main...feature

git log --oneline --first-parent

# Show only merge commits
git log --oneline --merges
 
# Show only non-merge commits (skip merge commits)
git log --oneline --no-merges

# Commits directly on the path between v1.0 and v2.0
git log --oneline --ancestry-path v1.0..v2.0

# Show only the last N commits
git log -5
git log -n 5
 
# Skip the first N commits
git log --skip=10 -5
 
# Stop after N commits total
git log --max-count=20

# Search current working tree
git grep "validateEmail"
 
# Search with line numbers
git grep -n "validateEmail"
 
# Case-insensitive
git grep -i "validateemail"
 
# Count matches per file
git grep -c "validateEmail"

# Search in the v1.0 tag
git grep "validateEmail" v1.0
 
# Search in a specific commit
git grep "validateEmail" abc1234
 
# Compare: current vs. old
git grep -c "TODO" HEAD
git grep -c "TODO" v1.0

# Show enclosing function/scope
git grep -p "validateEmail"
 
# Group results with headings (file name as header)
git grep --heading --break "validateEmail"
 
# Search with regex
git grep -e "validate.*Email" --and -e "return"
 
# Boolean combinations
git grep -e "error" --and -e "handler" -- "*.js"
 
# Invert match (lines NOT containing)
git grep -v "console.log" -- "*.js"

# Find the commit that first introduced "validateEmail" in any file
git log --oneline --all -S "validateEmail"
 
# Then see how it was used in that commit
git grep "validateEmail" abc1234

# Compact graph log (the everyday workhorse)
git config --global alias.lg "log --oneline --graph --decorate"
 
# Full graph with all branches
git config --global alias.lga "log --oneline --graph --decorate --all"
 
# Log with author and relative date
git config --global alias.ll "log --pretty=format:'%C(yellow)%h%C(reset) %s %C(cyan)(%ar)%C(reset) %C(blue)<%an>%C(reset)%C(red)%d%C(reset)'"
 
# Log with full date
git config --global alias.lf "log --pretty=format:'%C(yellow)%h%C(reset) %C(green)%ai%C(reset) %s %C(blue)<%an>%C(reset)%C(red)%d%C(reset)'"
 
# What did I do today?
git config --global alias.today "log --oneline --since='midnight' --author='$(git config user.name)'"
 
# What changed between this branch and main?
git config --global alias.ahead "log --oneline main..HEAD"
git config --global alias.behind "log --oneline HEAD..main"

[alias]
    lg = log --oneline --graph --decorate
    lga = log --oneline --graph --decorate --all
    ll = log --pretty=format:'%C(yellow)%h%C(reset) %s %C(cyan)(%ar)%C(reset) %C(blue)<%an>%C(reset)%C(red)%d%C(reset)'
    # Count commits by author
    who = shortlog -sn --no-merges
    # Show files changed in last commit
    last = diff-tree --no-commit-id --name-only -r HEAD

mkdir log-lab && cd log-lab
git init
 
# Simulate a multi-author project by configuring author per commit
# (using --author flag)
 
# Initial commit
cat > app.js << 'EOF'
function main() {
  console.log("App starting");
  initialize();
}
 
function initialize() {
  console.log("Initializing...");
}
 
module.exports = { main, initialize };
EOF
git add app.js
git commit --author="Alice Smith <alice@example.com>" -m "feat: initial application setup"
 
# Tag v1.0
git tag -a v1.0 -m "Version 1.0"
 
# Add config
cat > config.js << 'EOF'
const config = {
  port: 3000,
  host: "localhost",
  debug: false,
  logLevel: "info"
};
module.exports = config;
EOF
git add config.js
git commit --author="Bob Jones <bob@example.com>" -m "feat: add configuration module"
 
# Add utils
cat > utils.js << 'EOF'
function validateEmail(email) {
  return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email);
}
 
function formatDate(date) {
  return date.toISOString().split('T')[0];
}
 
module.exports = { validateEmail, formatDate };
EOF
git add utils.js
git commit --author="Alice Smith <alice@example.com>" -m "feat: add utility functions
 
Includes email validation and date formatting helpers.
These will be used across multiple modules."
 
# Create a feature branch
git checkout -b feature/auth
 
cat > auth.js << 'EOF'
const { validateEmail } = require('./utils');
 
function login(email, password) {
  if (!validateEmail(email)) {
    throw new Error("Invalid email");
  }
  // TODO: implement actual auth
  return { token: "abc123", user: email };
}
 
function logout(token) {
  // TODO: invalidate token
  return true;
}
 
module.exports = { login, logout };
EOF
git add auth.js
git commit --author="Carol Lee <carol@example.com>" -m "feat: add authentication module
 
Implements login and logout functions.
Uses email validation from utils."
 
echo '// Session management coming soon' >> auth.js
git add auth.js
git commit --author="Carol Lee <carol@example.com>" -m "chore: add session management placeholder"
 
# Switch back to main and make a parallel change
git checkout main
 
cat > logger.js << 'EOF'
const config = require('./config');
 
function log(level, message) {
  const levels = ['debug', 'info', 'warn', 'error'];
  if (levels.indexOf(level) >= levels.indexOf(config.logLevel)) {
    console.log(`[${level.toUpperCase()}] ${new Date().toISOString()}: ${message}`);
  }
}
 
module.exports = { log };
EOF
git add logger.js
git commit --author="Bob Jones <bob@example.com>" -m "feat: add logging module
 
Respects logLevel from config.
Supports debug, info, warn, error levels."
 
# Merge feature branch
git merge --no-ff feature/auth -m "Merge branch 'feature/auth' into main"
 
# More commits after merge
cat > config.js << 'EOF'
const config = {
  port: 3000,
  host: "localhost",
  debug: true,
  logLevel: "debug",
  sessionTimeout: 3600
};
module.exports = config;
EOF
git add config.js
git commit --author="Bob Jones <bob@example.com>" -m "fix: enable debug mode and add session timeout
 
BREAKING: debug is now true by default.
Added sessionTimeout config option."
 
# Tag v2.0
git tag -a v2.0 -m "Version 2.0 - Authentication release"
 
# A few more commits
echo "// Performance optimization" >> app.js
git add app.js
git commit --author="Alice Smith <alice@example.com>" -m "perf: optimize main startup sequence"
 
echo "// Error boundary" >> app.js
git add app.js
git commit --author="Alice Smith <alice@example.com>" -m "fix: add error boundary to main
 
Prevents unhandled exceptions from crashing the app.
Related to issue #42."
 
echo "// Metrics" >> logger.js
git add logger.js
git commit --author="Dave Wilson <dave@example.com>" -m "feat: add metrics collection to logger"
 
echo "# Project README" > README.md
git add README.md
git commit --author="Carol Lee <carol@example.com>" -m "docs: add project README"
 
echo ""
echo "Repository ready! Commits:"
git log --oneline --all

# 1. Default full format
git log -3
 
# 2. Compact oneline
git log --oneline
 
# 3. Graph with all branches
git log --oneline --graph --all --decorate
 
# 4. Full format (author + committer)
git log --format=full -1
 
# 5. Custom format — hash, subject, author, relative date
git log --pretty=format:"%C(yellow)%h%C(reset) %s %C(blue)<%an>%C(reset) %C(green)(%ar)%C(reset)"

# All commits by Alice
git log --oneline --author="Alice"
 
# All commits by Bob
git log --oneline --author="Bob"
 
# Commits by Alice OR Carol
git log --oneline --author="Alice\|Carol"
 
# Count commits per author
git shortlog -sn
 
# Commits in the last 30 minutes (should show your recent work)
git log --oneline --since="30 minutes ago"

# Find commits mentioning "auth" in the message
git log --oneline --grep="auth"
 
# Find commits mentioning "feat:" (conventional commit prefix)
git log --oneline --grep="feat:"
 
# Find commits mentioning "fix:"
git log --oneline --grep="fix:"
 
# Pickaxe: when was "validateEmail" introduced?
git log --oneline -S "validateEmail"
 
# Pickaxe: when was "debug: true" introduced?
git log --oneline -S "debug: true"
 
# Regex search: find commits that touched any TODO
git log --oneline -G "TODO"
 
# Invert grep: commits NOT mentioning "feat" or "fix" or "chore"
git log --oneline --grep="feat:\|fix:\|chore:" --invert-grep

# Commits that touched config.js
git log --oneline -- config.js
 
# Commits that touched anything in the project root
git log --oneline -- "*.js"
 
# History of the config object (line range)
git log -L 1,7:config.js
 
# What changed in auth.js across all commits?
git log -p -- auth.js

# What's on feature/auth that isn't on main?
git log --oneline main..feature/auth
# (Should be empty — it was merged)
 
# What was on feature/auth before it was merged?
# Use the merge commit's parents:
git log --oneline HEAD~4^2 --not HEAD~4^1
# Or more simply, look at the merge commit:
git log --oneline --first-parent
 
# What's between v1.0 and v2.0?
git log --oneline v1.0..v2.0
 
# What's happened since v2.0?
git log --oneline v2.0..HEAD
 
# Symmetric difference between v1.0 and HEAD
git log --oneline --left-right v1.0...HEAD

# Full history (with merge details)
git log --oneline --graph
 
# First-parent only (main line)
git log --oneline --first-parent
 
# Only merge commits
git log --oneline --merges
 
# Only non-merge commits
git log --oneline --no-merges

# Search for "validateEmail" in current code
git grep "validateEmail"
 
# With line numbers
git grep -n "validateEmail"
 
# Count occurrences per file
git grep -c "TODO"
 
# Search with function scope
git grep -p "validateEmail"
 
# Search at the v1.0 tag
git grep "validateEmail" v1.0
# (Should find nothing — utils.js didn't exist at v1.0)
 
# Search at v2.0
git grep "validateEmail" v2.0
# (Should find it in utils.js and auth.js)