log, diff, status

git log --oneline --graph --all

--oneline collapses each commit to one line. --graph draws the branch/merge topology. --all shows commits from every branch. This is the single most useful log command for understanding project history.

# Last 5 commits
git log -5

# Commits by a specific author
git log --author="Alice"

# Commits that touch a specific file
git log -- src/auth.ts

# Commits mentioning a keyword
git log --grep="fix"

# Commits after a date
git log --after="2026-01-01"

# Range between two commits
git log abc1234..def5678

These filters combine with each other. git log --author='Alice' --after='2026-01-01' -- src/auth.ts shows Alice's commits to src/auth.ts since January 1st.

git log --pretty=format:"%C(yellow)%h%C(reset) %C(blue)%ar%C(reset) %C(green)%an%C(reset) %s" -10

Color codes use %C(color) syntax. This format shows: short hash in yellow, relative time in blue, author in green, then the subject. Customize to match your team's preferences.

git log --pretty=format:"%h|%s|%an|%ad" --date=short -10

Pipe-delimited output is easy to parse with awk, cut, or any scripting language. Useful for generating changelogs or filtering commits programmatically.

# Working tree vs staging area (unstaged changes)
git diff

# Staging area vs last commit (staged changes)
git diff --staged

# Working tree vs last commit (everything)
git diff HEAD

This maps directly to the three states: working tree → staging area → repository. Use git diff for changes you have not staged yet. Use git diff --staged to review what you are about to commit.

# Show 3 lines of context (default is 3)
git diff -U5

# Show only filenames that changed
git diff --name-only

# Show only stats (files changed, insertions, deletions)
git diff --stat

# Word-level diff instead of line-level
git diff --word-diff

--word-diff highlights individual word changes within a line, which is useful for spotting small changes in long lines. --stat gives a quick overview of which files changed and by how much.

# Compare two branches
git diff main..feature-login

# Compare the last 3 commits on current branch
git diff HEAD~3..HEAD

# Compare a branch to its merge base with main
git diff main...feature-login

# Compare tags
git diff v1.0.0..v2.0.0

The two-dot .. compares two endpoints directly. The three-dot ... compares from the merge base (common ancestor) to the target — this shows only the changes on the feature branch, excluding commits already on main.

git status -s
#  M README.md      — modified, not staged
# A  app.js         — staged (new file)
# M  config.json    — staged modification
# D  old-file.txt   — staged deletion
# ?? temp.log       — untracked file
#!! .DS_Store       — ignored file

Column meanings: M = modified, A = added, D = deleted, R = renamed, C = copied, ?? = untracked, !! = ignored. Two columns show the staging vs working tree distinction at a glance.