Git walkthrough@modsaid

Outline

● Source Control● Git Basics● Configuration● Viewing history● Undoing● Aliases● Tagging● Branching● Remotes● Bare repos● Hosting: Github, bitbucket, ...● Git 2.0+

Version Control System

Centralized Version Control System

Distributed Version Control System

Git Basics

● Local Repo ( .git )● Working directory

Git Basics - The 3 States

Git Basics

● git init● git status● git add ● git commit● git reset● git clone

● git mv● git rm● git blame● git push● git pull

Git Basics - committing# Initializing a new repo

$ git init .

# Staging

$ git add .

$ git add -A

# committing

$ git commit -m “initial commit”

Git Basics - committing$ git status

# diff (working vs staged)

$ git diff

# diff (staged vs committed)

$ git diff -s

# Stage and commit in one shot

$ git commit -a -m “direct staging and commit”

Git Configuration

● System ● User ● repo

/etc/gitconfig

~/.gitconfig or ~/.config/git/config .git/config

Git Configuration

git config --system

git config --global

git config --local

Git Configuration$ git config --global user.name "John Doe"

$ git config --global user.email johndoe@example.com

$ git config --global core.editor emacs

$ git config --list

$ git config user.name

Viewing History$ git log$ git log -p -2$ git log --stat$ git log --grep adding$ git log --since=2.weeks$ git log --Sfunction_name$ git log --pretty=oneline$ git log --pretty=format:"%h - %an, %ar : %s"

Viewing History$ git log --pretty=format:"%ad %an : %s " --date=short

$ git log --pretty=oneline --since=”2012-12-20” --until=”2013-01-01” -5

$ git log --pretty=oneline | wc -l #no of commits

$ git log --pretty=format:%cd --date=short | uniq | wc -l #no of working days

Viewing History$ git shortlog

$ git shortlog -s | wc -l #no of devs

$ git shortlog -se # list of devs

#no of coding days

$ git log --pretty=format:”%ad” --date=short | uniq | wc -l

Viewing History - mapping names$ git shortlog -se | grep -i john

6 John Doe <john.doe@espace.com.eg> 10 John-Doe <john.doe@espace.com.eg> 4 John.Doe <john.doe@espace.com.eg>

$ vim .mailmapname1 name2 name3 mail@example.comname4 mail@example.com

$ git shortlog -se > .mailmap

Undoinggit commit --amend

# Changing commit message$ git commit --amend -m “better commit message”

# Adding forgotten file$ git commit -m 'initial commit'$ git add forgotten_file$ git commit --amend

Undoing#Unstaging$ git add .$ git status$ git reset HEAD benchmarks.rb

#dropping local commits <DANGER>git reset --hard HEAD~3

Git Aliases$ git config --global alias.co checkout

$ git config --global alias.ci commit

$ git config --global alias.st status

$ git config alias.showdevs 'shortlog -s'

$ git config --global alias.unstage 'reset HEAD --'

Tagging

● Lightweight: pointer to specific commit$ git tag before-optimization

● Annotated: full objects, checksummed, contains tagger info, suitable for releases$ git tag -a v1.4 -m 'my version 1.4'

Tagging#Tagging later$ git tag -a v1.2 9fceb02

$ git show v1.2

$ git push origin v1.5

$ git push origin --tags

Branching$ git branch #List current branches

$ git branch newone # create a new branch newone$ git checkout newone # switch to newone branch

# create branch and switch in one step$ git checkout -b newtwo

Branching# Committing on master

Branching$ git branch testing

Branching

Branching$ git checkout testing

Branching$ git commit -a -m “some change”

Branching$ git checkout master

Branching$ git commit -a -m “master commit”

Branching - Merging$ git merge testing

# in case of conflicts (failed auto merge)$ git mergetool

Branching - Merging

fast-forward

git merge feature

no fast-forward

git merge --no-ff feature

Remotes# Listing remotes

$ git remote

$ git remote -v

# Adding a remote

$ git remote add [shortname] [url]

$ git remote show origin

Remotes# Fetching updates$ git fetch [remote-name]

$ git remote rename pb paul

$ git remote rm paul

Bare Repos

● git repo with no working directory● The git server side$ git init --bare .

# Cloning (backup)

$ git clone --bare git@github.com:modsaid/git-demo2.git

# Restoring

$ git push --mirror git@bitbucket.org:modsaid/git-demo2.git

Hosting: github, bitbucket

● Github: the most popular, free public repos ● Bitbucket: free private with limited

collaborators● A lot others

Github

● Exploring repos● Pull Requests● Contribution to repos:

○ Fork○ Fix/Add○ Send pull request

https://help.github.com/articles/fork-a-repo/

Latest git

The latest git release today is 2.3.3

Installing the latest git (2.3)

$ sudo add-apt-repository ppa:git-core/ppa

$ sudo apt-get update

$ sudo apt-get install git

What’s new in Git 2.0

“From the point of view of end-users who are totally new to Git, this release will give them the defaults that are vastly improved compared to the older versions, but at the same time, for existing users, this release is designed to be as low-impact as possible as long as they have been following recent releases along.”

● Better Defaults

what’s new? git push

pre git 2.0

● Default: matching

starting git 2.0

● Default: simple

git config push.default

● ( nothing | current | upstream | simple | matching )

what’s new? git add -upre git 2.0

● stage files in working directory

starting git 2.0

● stage files in the Repo Directory

what’s new? git diff -q

pre git 2.0

● valid option

starting git 2.0

● Removed

Do not display deleted files during git diff

what’s new?● https://raw.githubusercontent.com/git/git/master/Documentation/RelNotes/2.0.0.txt● https://raw.githubusercontent.com/git/git/master/Documentation/RelNotes/2.1.0.txt● https://raw.githubusercontent.com/git/git/master/Documentation/RelNotes/2.2.0.txt● https://raw.githubusercontent.com/git/git/master/Documentation/RelNotes/2.3.0.txt

Resources

● Pro Git, Second EditionBy: Scott Chacon; Ben StraubPublisher: ApressPub. Date: November 19, 2014

● git help COMMAND (man pages)● Git Recipes by BasayelSaid

Thank You