This document provides an introduction and overview of using Git for version control. It discusses the basics of version control systems including local version control, centralized version control, and distributed version control. It then walks through setting up Git locally and configuring it, generating SSH keys, creating repositories on GitHub, forking repositories, and basic Git commands and workflows for branching, merging, and working with remotes.

1. Git Introduction
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2. 為什麼要做版本控制？？
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3. LocalVersion Control Systems
• 在自己電腦裡，建立⼀一
個版本資料庫
• 最簡單的作法
Problem:如何協作？？
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4. CentralizedVersion Control Systems
• Server上，會儲存所有的
版本及記錄
• Checkout & Commit
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5. DistributedVersion Control Systems
• 大家都有完整的資料庫
• 大家都能獨立工作
• Server壞了只要拿到⼀一份
完整的資料庫便可復原
• Git, Mecurial(hg),
bazaar(bzr)
Problem:相較於Centralized
混亂。
提供好的Branch機制解決
此問題。
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6. https://help.github.com/articles/set-up-git
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7. Set up Git
https://help.github.com/articles/set-up-git
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8. $ git config --global user.name "Your Name Here"
# Sets the default name for git to use when you commit
$ git config --global user.email "your_email@youremail.com"
# Sets the default email for git to use when you commit
$ git credential-osxkeychain
# Test for the cred helper
Usage: git credential-osxkeychain <get|store|erase>
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9. $ git credential-osxkeychain
# Test for the cred helper
git: 'credential-osxkeychain' is not a git command. See 'git
--help'.
$ curl -s -O http://github-media-downloads.s3.amazonaws.com/
osx/git-credential-osxkeychain
# Download the helper
$ chmod u+x git-credential-osxkeychain
# Fix the permissions on the file so it can be run
$ sudo mv git-credential-osxkeychain /usr/local/git/bin
# Move the file so git can access it
# Password: [enter your password]
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10. $ git config --global credential.helper osxkeychain
# Set git to use the osxkeychain credential helper
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11. Get a Github account
https://github.com/
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12. https://help.github.com/articles/generating-ssh-keys
Generate SSH Keys
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13. $ cd ~/.ssh
$ ls
config id_rsa id_rsa.pub known_hosts
$ mkdir key_backup
$ cp id_rsa* key_backup
$ rm id_rsa*
$ ssh-keygen -t rsa -C "your_email@youremail.com"
# Creates a new ssh key using the provided email
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/you/.ssh/id_rsa):
[Press enter]
Enter passphrase (empty for no passphrase): [Type a
passphrase]
Enter same passphrase again: [Type passphrase again]
Your identification has been saved in /Users/you/.ssh/id_rsa.
Your public key has been saved in /Users/you/.ssh/id_rsa.pub.
The key fingerprint is:
01:0f:f4:3b:ca:85:d6:17:a1:7d:f0:68:9d:f0:a2:db
your_email@youremail.com
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14. $ pbcopy < ~/.ssh/id_rsa.pub
# Copies the contents of the id_rsa.pub file to your clipboard
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15. $ ssh -T git@github.com
# Attempts to ssh to github
The authenticity of host 'github.com (207.97.227.239)' can't
be established.
RSA key fingerprint is 16:27:ac:a5:76:28:2d:36:63:1b:
56:4d:eb:df:a6:48.
Are you sure you want to continue connecting (yes/no)?
Hi username! You've successfully authenticated, but GitHub
does not provide shell access.
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16. Create a Repo
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17. 17

18. 18

19. $ mkdir ~/Hello-World
# Creates a directory for your project called "Hello-World"
in your user directory
$ cd ~/Hello-World
# Changes the current working directory to your newly
created directory
$ git init
# Sets up the necessary Git files
Initialized empty Git repository in /Users/you/Hello-
World/.git/
$ touch README
# Creates a file called "README" in your Hello-World
directory
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20. $ git add README
# Stages your README file, adding it to the list of files to
be committed
$ git commit -m 'first commit'
# Commits your files, adding the message "first commit"
$ git remote add origin https://github.com/username/Hello-
World.git
# Creates a remote named "origin" pointing at your GitHub
repo
$ git push origin master
# Sends your commits in the "master" branch to GitHub
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21. Fork A Repo
$ git clone git@github.com:oboegrace/git-101.git
https://help.github.com/articles/fork-a-repo
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22. Git Basics
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23. Snapshots, Not Differences
SVN
Git
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24. Nearly Every Operation is Local
• 不只有⼀一份完整的資料
庫
• 閱讀版本歷史、提交
變更這些動作都可以
在本機進行
• 不需網路連線也可以工
作
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25. Git Has Integrity
• 使用 Checksum 來確保檔案的完整性
• 設計上只會增加資料，因此可以輕鬆復
原
• 在本機的檔案管理中，增添了Staging的
觀念
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26. TheThree States of Git
• Committed
• Data is safely stored in your local database.
• Modified
• You have changed the file but have not committed it to your
database yet.
• Staged
• You have marked a modified file in its current version to go
into your next commit snapshot.
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27. The basic workflow of Git
1. You modify files in your
working directory.
2. You stage the files,
adding snapshots of
them to your staging
area.
3. You do a commit, which
takes the files as they
are in the staging area
and stores that snapshot
permanently to your Git
directory.
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28. Using Git
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29. Installing Git
• Installing on Mac
• http://code.google.com/p/git-osx-installer
• Installing on Windows
• http://code.google.com/p/msysgit
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30. Initializing a Repository in an Existing Directory
• Repository就是⼀一份版本控制中心的版本
資料庫
• $ git init
• 資訊會放在.git資料夾裡
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31. Initial Commit
• Add files
• And commit it!
$ touch README
$ git add .
$ git commit -m 'Initial commit'
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32. Cloning an Existing Repository
$ git clone git://github.com/schacon/grit.git
Checking the Status ofYour Files
$ git status
# On branch master
nothing to commit (working directory clean)
Ignoring Files
$ cat .gitignore
*.[oa]
*~
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33. CommittingYour Changes
$ git commit
Removing Files
$ git rm grit.gemspec
rm 'grit.gemspec'
$ git status
# On branch master
#
# Changes to be committed:
# (use "git reset HEAD <file>..." to unstage)
#
# deleted: grit.gemspec
#
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34. ChangingYour Last Commit
$ git commit --amend
Unstaging a Staged File
$ git reset HEAD aFile
Unmodifying a Modified File
$ git checkout -- aFile
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35. Working with Remotes
• Branch 和 Remote 之間的互動
• 預設的 Branch 叫 Master
• 預設的 Remote 叫 Origin
• $ git pull origin :
$ git fetch origin
$ git merge origin/master
• $ git push origin master
push
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36. What a Branch Is
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37. Single commit repository data.
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38. Git object data for multiple commits.
Branch pointing into the commit data’s history.
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39. $ git branch testing
git branch <new_branch_name> 建立本地 local branch
git branch 列出目前有那些 branch 以及目前在那個 branch
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40. $ git checkout testing
This moves HEAD to point to the testing branch
此時如果commit...
git checkout <branch_name> 切換 branch
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41. 41

42. $ git checkout master
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43. $ git commit -a -m 'made other changes'
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44. http://learn.github.com/p/branching.html
Practice Branching and Merging
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45. 如何重新變回⼀一條?
• Merge
• 把岔開來的分支在往後合起來
• 通常的建議方式
• Rebase
• 把岔開來的分支裝回去主線
• 還沒Push出去的東西才可以Rebase!
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46. Basic Branching and Merging
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47. 有緊急的Bug，開了一個 hotfix branch 處理好了。
現在要怎麼處理 master?
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48. $ git checkout master
$ git merge hotfix
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49. 此時處理完iss53，那該如何Merge?
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50. $ git checkout master
$ git merge iss53
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51. Basic Merge Conflicts
• git status ⼀一下看是哪個檔案出問題
• 到出問題的檔案找問題，手動解決
• 再檢查 git status 後，用 git commit 手動
Merge (會自動生成 Merge 的 Commit Message)
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52. Rebase
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53. 除了Merge以外，我有沒有其他的辦法可以處理
掉 experiment branch?
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54. $ git checkout experiment
$ git rebase master
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55. $ git checkout master
$ git merge experiment
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56. $ git clone git@github.com:oboegrace/git-101.git
Let’s practice it!
1. Set up git https://help.github.com/articles/set-up-git
2. Generate SSH Keys https://help.github.com/articles/generating-ssh-keys
3. Create a repo https://help.github.com/articles/create-a-repo
4. Fork a repo https://help.github.com/articles/fork-a-repo
5. Be social https://help.github.com/articles/be-social
6. Normal Workflow http://learn.github.com/p/normal.html
7. Branching and merging http://learn.github.com/p/branching.html
8. Distributed Git http://learn.github.com/p/remotes.html
9. Git history http://learn.github.com/p/log.html
10.Git reference http://gitref.org/
Reference
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