Master Git: Essential Commands, Workflows, and Best Practices

Git Flow Diagram

Workspace

: 工作区 Index / Stage: 暂存区 Repository: 仓库区（或本地仓库） Remote: 远程仓库

Configuring Git

# Configure global user
$ git config --global user.name "用户名"
$ git config --global user.email "git账号"
# Alias shortcuts
$ git config --global alias.co checkout
$ git config --global alias.ss status
$ git config --global alias.cm commit
$ git config --global alias.br branch
$ git config --global alias.rg reflog
$ git config --global alias.lg "log --color --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit"
# Remove a global alias
$ git config --global --unset alias.xxx
$ git config --global --unset user.xxx

Viewing Git Information

# List system config
$ git config --list
# Show user config
$ cat ~/.gitconfig
# Show repository config
$ cat .git/config
# List files in the index
$ git ls-files
# Show reflog
$ git reflog
# Show help for all commands
$ git --help -a
# Show HEAD reference
$ cat .git/HEAD
# Show commit log (examples)
$ git log --oneline --grep="关键字" --graph --all --author "username" --reverse -n --stat --abbrev-commit --pretty=format:"xxx"

git reflog

Shows a list of HEAD changes over time. It records commits when you switch branches, commit, or reset, but not when you checkout a file or stash changes, because those actions do not create new commits.

Git periodically cleans up unused reflog entries, so old entries may disappear.

git log graph

In Git, a branch is a pointer. Creating a new branch creates a new pointer based on the current one. Switching branches moves HEAD to point to a different branch or commit.

Symbols:

*	表示一个 commit
|	表示分支前进
/	表示分叉
\	表示合入
|/	表示新分支

Common Git Commands

# Show status of workspace and index
$ git status
# Add all changes to index
$ git add .
# Commit with message
$ git commit -m "本次提交说明"
# Shortcut: add and commit (tracked files only)
$ git commit -am "本次提交说明"
# Push local branch to remote
$ git push -u origin branchName
# Pull remote branch
$ git pull origin branchName
# Merge a branch
$ git merge branchName
# List local branches
$ git branch
# List all branches (local + remote)
$ git branch -a
# Switch branch
$ git checkout branchName
# Stash changes
$ git stash
# Apply stash
$ git stash pop

Detailed Command Explanations

add

Add files to the index (staging area). git add .: stages all changes in the current directory. git add -u: stages modifications and deletions of tracked files. git add -A: stages all changes, including new, modified, and deleted files.

status

# Show status of workspace and index
$ git status

commit

# Commit staged changes with a message
$ git commit -m "本次提交的说明"
# Add and commit in one step (tracked files only)
$ git commit -am "本次提交的说明"
# Amend the previous commit
$ git commit --amend
# Amend with a new message without opening editor
$ git commit --amend --no-edit

Never amend a commit that has already been pushed to a public repository.

push & pull

# Push local branch to remote
$ git push origin branchName
# Push all branches
$ git push --all origin
# Pull and merge remote branch
$ git pull origin branchName
# Fetch without merging
$ git fetch origin branchName
# Force push (use with caution)
$ git push --force origin

branch

# List branches
$ git branch -a
# Create a new branch
$ git branch newBranch
# Switch to a branch
$ git checkout newBranch
# Create and switch in one step
$ git checkout -b newBranch
# Delete a branch
$ git branch -d oldBranch
# Force delete a branch
$ git branch -D oldBranch
# Rename current branch
$ git branch -m newName

merge

# Fast-forward merge (default)
$ git merge
# No fast-forward (creates a merge commit)
$ git merge --no-ff
# Squash merge (does not create a merge commit)
$ git merge --squash

rebase

Rebase rewrites commit history by moving a series of commits onto a new base. It is useful for linearizing history but should not be used on public branches.

stash

# Save uncommitted changes
$ git stash
# Save with a message
$ git stash save "message"
# Include untracked files
$ git stash -u
# List stashes
$ git stash list
# Apply a stash without dropping it
$ git stash apply stash@{0}
# Apply and drop
$ git stash pop stash@{0}
# Drop a stash
$ git stash drop stash@{0}
# Clear all stashes
$ git stash clear

diff

# Compare workspace with index
$ git diff
# Compare index with last commit
$ git diff --cached
# Compare two branches
$ git diff branchA..branchB
# Compare two commits
$ git diff commit1..commit2

remote

# List remotes
$ git remote
# Show remote URLs
$ git remote -v
# Add a remote
$ git remote add origin <url>
# Change remote URL
$ git remote set-url origin <newurl>
# Remove a remote
$ git remote rm origin

tag

# Create a lightweight tag
$ git tag v1.0
# Create an annotated tag
$ git tag -a v0.1 -m "version 0.1 released"
# List tags
$ git tag
# Show tag details
$ git show v1.0
# Push a tag
$ git push origin v1.0
# Push all tags
$ git push origin --tags
# Delete a local tag
$ git tag -d v0.1
# Delete a remote tag
$ git push origin :refs/tags/v0.1

Deleting Files

# Delete from index and workspace
$ git rm filename
# Delete only from index (keep in workspace)
$ git rm --cached filename

Reset, Revert, and Cherry-pick

# Reset (soft, mixed, hard)
$ git reset --soft HEAD~1   # keep changes in index
$ git reset --mixed HEAD~1  # keep changes in workspace
$ git reset --hard HEAD~1   # discard all changes
# Revert a commit (creates a new commit that undoes changes)
$ git revert <commit_id>
# Cherry-pick a commit onto current branch
$ git cherry-pick <commit_id>

Creating a Git Project

# Initialize a new repository and add remote
$ git init
$ git remote add origin <repo_url>
# Or clone an existing remote repository
$ git clone <repo_url>
$ git clone <repo_url> <project-name>

Branch Management Guidelines

Typical workflow uses multiple long‑living branches:

develop : development branch where daily changes are merged.

test : testing branch after feature integration.

release : pre‑release branch for final verification.

master : production branch; code is deployed from here.

bug : short‑lived branch created from release or master to fix urgent issues.

Git Hooks

Hooks are scripts stored in .git/hooks that run at various points in the Git workflow. They can be client‑side (e.g., pre‑commit) or server‑side.

pre‑commit

Runs before a commit is created. It can run linters, tests, or other checks. If the script exits with a non‑zero status, the commit is aborted.

# Install pre‑commit via npm
npm install pre-commit --save-dev
# Configure in package.json
"pre-commit": ["eslint"]
# Skip pre‑commit checks
$ git commit --no-verify

Common Issues and Solutions

“fatal: refusing to merge unrelated histories” – use --allow-unrelated-histories with git pull or git merge.

Merge conflicts – resolve files, then git add and git commit or abort with git merge --abort.

Authentication failures – verify remote URL protocol (SSH vs HTTPS) and update credentials or SSH keys.

Locked repository – delete .git/index.lock if a previous Git process crashed.

Push rejected because of non‑fast‑forward – pull and merge first, or force push if appropriate.