How to contribute code using git¶

Page last updated on: 2020-07-07

Part 1. One-time set up¶

Identity:¶

$ git config --global user.name "<Your Name>"  
$ git config --global user.email <your email>

Save credential for 6 hours:¶

$ git config --global credential.helper 'cache --timeout=21600'

Save credential permanently:¶

$ git config --global credential.helper store

Alias of showing git history:¶

Add this to ~/.gitconfig

[alias]
lg = log --graph --abbrev-commit --decorate --format=format:'%C(bold blue)%h%C(reset) - %C(bold green)(%ar)%C(reset) %C(white)%s%C(reset) %C(dim white)- %an%C(reset)%C(bold yellow)%d%C(reset)' --all

Part 2. Start a new repository¶

git picture

Clone a remote repo:¶

Clone a remote repo to local computer:

$ git clone <url>

Convert a local directory:¶

Convert an existing local directory to local git repository:

$ git init

Part 3. Single line development:¶

Add all files to track:¶

$ git add .

Check status:¶

$ git status

Commit:¶

$ git commit -a -m "<commit message>"

Add a file to track:¶

$ git add <file name>

Show history:¶

$ git lg

It requires you set up the “lg” alias in ~/.gitconfig

Part 4. Go to past commits¶

Create a new branch and revert to a past commit:

$ git checkout -b <new branch> <commit hash>

<new branch> is a branch name you make.

<commit hash> is the string as reported by git log

If you want to make this branch as the new master branch, do a swap as following:

make sure your are in the new branch
```
$ git checkout <new branch>
```
force master to merge with current branch and use current branch as favored:
```
$ git merge -s ours master
```

go to the master branch and reconcile again:

$ git checkout master
$ git merge <new branch>

after merge, delete the branch.
```
$ git branch -d <new branch>
```

Part 5. Multi-line development¶

Show branches:¶

$ git branch

¶

Show remote branches:

$ git branch -r

Switch between branches:¶

$ git checkout <branch name>

Create and switch branch:¶

$ git checkout -b <branch name>

Merge branches:¶

$ git merge <another branch>

This will merge a branch to current branch:

Merge with current favored:¶

$ git merge -s ours <another branch>

Delete branches¶

$ git branch -d <branch name>

Force delete:¶

$ git branch -D <branch name>

Part 6. Sync remote and local¶

Check remote:¶

$ git remote -v

“origin” is the default name of your first remote.

Add more remotes:¶

$ git remote add <remote> <url>

Pull from remote repo:¶

$ git pull

Or

$ git pull <remote> <branch>

Push to remote:¶

$ git push

Push new local branch to remote:¶

$ git push -u <remote> <branch>

Delete remote branch:¶

$ git push <remote> --delete <branch>

Delete remote tracking branch:¶

$ git remote prune <remote>

Part 7. Merge branches¶

Common scenario of merge:¶

Start a new feature:
```
$ git checkout -b new-feature
```
Edit some files, then commit the change:
```
$ git commit -a -m "Start a feature"  
```

Edit some files, then commit more changes:

$ git commit -a -m "Finish a feature"

Merge in the new-feature branch:

$ git checkout master 
$ git merge new-feature 
$ git branch -d new-feature

Conflict in merge:¶

When conflicts occur, the conflicting files will have visual marks like:

<<<<<<< master
conflicting text in receiving branch
=======
conflicting text in merging branch
>>>>>>> branch

You need to edit text and remove <<<<<<, ======, >>>>>> lines.

Then run a commit:

$ git commit -a -m "<commit message>"

Last update: 2020-07-07