Git Log — Powerful Commit History Filtering

git log                            # Full history
git log --oneline                  # One line per commit
git log --oneline -5               # Last 5 commits
git log --oneline --graph          # Show branch structure
git log --oneline --all            # All branches
git log --oneline --since="2 weeks ago"
git log --oneline --until="2024-01-01"

git log --author="Alice"
git log --author="Alice\|Bob"      # Multiple authors
git log --committer="Charlie"      # By committer

# List all contributors
git shortlog -sn
# Alice  42 commits
# Bob    37 commits
# Charlie 12 commits

git log --after="2024-01-01"
git log --before="2024-06-01"
git log --after="2 weeks ago"
git log --since="2024-01-01" --until="2024-03-01"
git log --after="yesterday"

git log --oneline -- login.py          # Commits touching this file
git log --oneline -- src/              # Commits in this directory
git log --oneline -- "*.js"            # Commits touching JS files
git log --oneline -- src/ -- "*.css"   # Multiple paths

# Follow a file through renames
git log --follow -- login.py

git log --grep="fix"                    # Commits with "fix" in message
git log --grep="fix\|bug"              # Multiple patterns
git log --grep="security" -i           # Case-insensitive
git log --grep="vulnerability" --oneline --all

git log -p                           # Show full diff for each commit
git log -p -- login.py               # Diff for a specific file
git log --stat                       # Show changed files and stats
git log --shortstat                  # Summary of changes
git log --name-only                  # Only list changed files
git log --name-status               # + changed files with status

# Custom format string
git log --pretty=format:"%h - %an, %ar : %s"

# Common placeholders:
# %h  = abbreviated commit hash
# %H  = full commit hash
# %an = author name
# %ae = author email
# %ad = author date
# %ar = relative date
# %s  = subject
# %d  = ref names (branches, tags)
# %b  = body

# Show branch topology
git log --oneline --graph --all --decorate

# Show first-parent ancestry (skip merge commits)
git log --first-parent --oneline

# Show only merge commits
git log --merges
git log --no-merges       # Exclude merge commits

# Search all refs (including ones no longer reachable)
git log --oneline --all --grep="WIP"

# Search reflog
git reflog
git log --oneline -g      # Walk reflog entries

# Who changed the most lines this month?
git log --after="1 month ago" --format='%an' | sort | uniq -c | sort -rn

# Total commits per author
git shortlog -sn

# Files changed most often
git log --pretty=format: --name-only | sort | uniq -c | sort -rn | head -20

# Commit activity per day of week
git log --date=format:"%a" --format="%ad" | sort | uniq -c | sort -rn