Git Tips and Tricks

Let's become a Git master

1. Git Basics

(1) Start project management with Git : git init

• Create a TIL folder to record what you learn going forward. Create this folder at the top level

• After moving to the TIL folder in git bash, start git management with the following command

git init

(2) Staging for Commit : git add

• Select files to take a snapshot of the current code state (== Add files to Staging Area)

git add [filename] # . uploads all changes to staging area

(3) Save snapshot for version management : git commit

• commit the snapshot of the current state to proceed with version management.

git commit -m "commit message"

(4) Add remote repository information : git remote

• Create a Github remote repository and connect it with the TIL folder

• Enter only when a new remote repository is added.

git remote add origin [github remote repository address]

(5) Pull code to local repository git pull

• Pull code from Github remote repository and apply commits for each branch.

git pull

git pull [remote repository name] (specify a remote to pull from)

(5) Push code to remote repository git push

• Finally push to Github remote repository.

git push

git push origin master

Tip

: If the current branch is the branch of the repo you want to push to, you only need to enter $ git push command!

(6) Other commands

• Check current git status git status

git status

• Check version management history

git log

• git configuration (user.name & user.email) : Set once at the beginning

git config --global user.name "Chloe Kim"
git config --global user.email "[e-mail]"

• Undo git add before commit

git reset

2. README.md

A markdown document that records information about remote repository. Generally describes how to use the project.

(1) Create README.md file

• Create README.md file in the TIL folder (top level). The name must be set to README.md.

touch README.md

(2) Add simple content about (your own) principles

• Write the README.md file based on what you learned and practiced in the markdown writing pdf.

• Write freely in format but follow markdown syntax (semantic).

(3) Save and version management : add, commit, push

• When writing is complete, leave commit history and push to remote repository with the following commands.

git add README.md
git commit -m "add README.md"
git push origin master

3. Shared Repository

Fast forward merge practice

# Check branch
$ git branch

# Create new branch
$ git branch [branch name]

# Move to another branch
$ git switch [branch name to move to]

# Move to another branch ver2)
$ git checkout [branch name to move to]


# Delete branch
$ git branch -d [branch name to delete]

# FF(=Fast Forward) merge
# : Move to the main branch and proceed (ex. move to master and create chloe)
$ git merge [branch name to merge]

# Create new branch and move
$ git switch -c [new branch to create]

# Create new branch and move ver2)
$ git checkout -b ashley  # -b means branch


# View git log as graph
$ git log --oneline --graph

4. Go back to specific point

Go back based on specific commit

git checkout f008d8f

Create test branch and move

$ git checkout -b test
$ git log --oneline
f008d8f (HEAD -> test) 05 | Article Index
c2be3bc 04 | Article Model
0d28d53 03 | startapp articles
5afc6a9 02 | settings
a046911 01 | startproject

Check reference log

git reflog

Check where head is

$ git log --oneline
fc58709 (HEAD -> master, origin/master, origin/HEAD) Add README.md
fd2e992 06 | Article C with ModelForm
f008d8f (test) 05 | Article Index
c2be3bc 04 | Article Model
0d28d53 03 | startapp articles
5afc6a9 02 | settings
a046911 01 | startproject

Go back to test branch

$ git checkout test
Switched to branch 'test'

5. Revert commits uploaded to remote repository

Method 1) Revert commit locally then force Push

Revert commit with $ git reset

git reset --hard HEAD       (going back to HEAD)

git reset --hard HEAD^      (going back to the commit before HEAD)

git reset --hard HEAD~2     (going back two commits before HEAD)
git reset --hard HEAD^^    (another syntax for going back two commits)

Force Push with -f or --force command

git push -f origin master

git push --force origin master

Method 2) Use git revert

• Method 1 has the problem of forcibly manipulating remote repository commit history

• but, using git revert treats the work of reverting commits as one commit and adds it to commit history

Create another commit that removes changes from specific commit

git revert --no-commit [hash of commit to revert]     

git revert --no-commmit [range of commits to revert]

git revert --no-commit Head~3

+

• Content in master branch is automatically deployed

  • master is in deployable state

Clone only specific branch

git clone -b {branch_name} --single-branch {repository URL}

Get specific branch from remote repository

First check what branches exist in remote repository

git branch -r

Check remote repository + local branches

git branch -a

Get branch from remote repository with same name

git checkout -t [origin/remote repository branch name to get]

Get branch from remote repository with name change

git checkout -b [branch name to create][remote repository branch name to get]

Modify unpushed Commit message

git commit --amend

git fetch

Can check how far remote branch has gone

• git pull == git fetch && merge

git rebase

Reposition

• Adding -i at the end allows interactive execution

6. Using Submodule

What is Submodule?

• Having another sub repo inside Git main repo

  • main repo does not manage sub repo!

• Using Submodule allows sharing commonly used logic between projects!

Add Submodule

git submoduel add [repo address]

• After this, you can commit without separate git add

Update Submodule

Update main repo

git pull

• Running the following command at main repo root updates main repo

Update sub repo

git submodule update --remote --merge

• Running the above command at main repo root updates sub repo according to the relationship between updated main repo and sub repo