<note>
  * [[https://backlogtool.com/git-guide/tw/|連猴子都能懂的Git入門指南]]
  * [[https://gitbook.tw/|為你自己學 Git]]
  * [[https://ihower.tw/git/|Git 版本控制系統]]
  * [[http://sethrobertson.github.io/GitFixUm/fixup.html|On undoing, fixing, or removing commits in git]]
</note>
先設定環境帳號。請見
  * [[http://plog.longwin.com.tw/my_note-unix/2009/05/15/git-initial-env-setup-2009|Git 基礎設定 (帳號的環境參數設定)]]。
  * [[http://blog.gogojimmy.net/2012/01/17/how-to-use-git-1-git-basic/|Git 教學(1) : Git 的基本使用]]
<code bash>
# 設定都存放在 ~/.gitconfig
$ git config --global user.name "陳韋任 (Wei-Ren Chen)"
$ git config --global user.email chenwj.cs97g@g2.nctu.edu.tw
</code>

origin(remote) 是遠端伺服器上的倉儲; master(branch) 是本地端正在修改的分支，master 是預設的分支名稱。關於 Git 基礎知識請見 [[http://static.slidesharecdn.com/swf/ssplayer2.swf?doc=giteveryone-101022053442-phpapp02|寫給大家的 Git 教學]]。

  * [[https://gitbook.tw/chapters/using-git/working-staging-and-repository.html|工作區、暫存區與儲存庫]]
{{https://gitbook.tw/images/using-git/working-staging-and-repository/all-states.png?500}}

  * [[https://gitbook.tw/chapters/gitflow/why-need-git-flow.html|Git Flow 是什麼？為什麼需要這種東西？]]
    * [[https://about.gitlab.com/2016/10/25/gitlab-workflow-an-overview/|GitLab Workflow: An Overview]]
    * [[https://www.atlassian.com/git/tutorials/comparing-workflows/gitflow-workflow|Gitflow Workflow]]
    * [[http://www.devops-blog.net/git/git-flow-how-its-used-and-why-you-should|Git-Flow | How it’s used and why you should]]
====== 初始設定 ======
  * [[http://sweetme.at/2013/09/13/git-logs-with-color/|Git Logs With Color and Graphs]]
  * [[http://codeinthehole.com/writing/a-useful-template-for-commit-messages/|A useful template for commit messages]]
  * [[https://chris.beams.io/posts/git-commit/|How to Write a Git Commit Message]]
<code bash>
$ git config --global alias.lg "log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit --date=relative"
</code>
====== 創建分支 ======
  * 預設分支為 master，建立額外分支 dev，並在分支 dev 上開發，避免在 master 上進行試驗性改動。分支 master 主要用來和上游同步。
    * [[https://git-scm.com/book/en/v2/Git-Branching-Basic-Branching-and-Merging/|3.2 Git Branching - Basic Branching and Merging]]
    * [[https://www.digitalocean.com/community/tutorials/how-to-use-git-branches|How To Use Git Branches]]
    * [[http://stackoverflow.com/questions/5531362/why-git-keeps-showing-my-changes-when-i-switch-branches-modified-added-deleted|Why git keeps showing my changes when I switch branches (modified,added, deleted files) no matter if I run git add or not?]]
    * [[http://stackoverflow.com/questions/16329776/how-to-keep-a-git-branch-in-sync-with-master|How to keep a git branch in sync with master]]

<code bash>
$ git branch -b dev
</code>

====== 切換分支 ======
  * 避免切換分支時，將分支 dev 未 commit 的修改帶到分支 master。
    * [[https://git-scm.com/book/en/v1/Git-Tools-Stashing|6.3 Git Tools - Stashing]]
<code bash>
$ git stash
$ git checkout master
$ git checkout dev
$ git stash pop
</code>
====== 刪除分支 ======
  * 分支 dev 合入 master，刪除分支 dev。
<code bash>
$ git branch -D dev
</code>
====== 加入提交 ======
<code bash>
$ git add -u :/
</code>

====== 重定基準 ======
  * 建議先將分支 dev 基於分支 master 做 rebase，再做後續的合併提交。分支 master 負責跟上游同步。 
    * [[https://git-scm.com/book/en/v2/Git-Branching-Rebasing|3.6 Git Branching - Rebasing]]
    * [[https://blog.yorkxin.org/2011/07/29/git-rebase|Git-rebase 小筆記]]

<code bash>
$ git checkout master
$ git pull
$ git checkout dev
$ git rebase master
</code>

====== 合併提交 ======
  * 在分支 dev 上開發，最後將數個 commit 合併成一個 commit 給 reviewer/committer 審閱。
    * [[http://gitready.com/advanced/2009/02/10/squashing-commits-with-rebase.html|squashing commits with rebase]]
    * [[https://ariejan.net/2011/07/05/git-squash-your-latests-commits-into-one/|Git: Squash your latests commits into one]]
<code bash>
$ git rebase -i HEAD~4 # 合併最近 4 個 commit
</code>

====== 分割提交 ======
  * 避免單一 commit 過大，將其分割成數個 commit，各自相對獨立且可測試。
    * [[https://emmanuelbernard.com/blog/2014/04/14/split-a-commit-in-two-with-git/|Split a commit in two with Git]]
    * [[http://stackoverflow.com/questions/4307095/how-can-i-split-up-a-git-commit-buried-in-history|How can I split up a Git commit buried in history?]]

====== 修改提交訊息或內容 ======
  * [[http://stackoverflow.com/questions/179123/how-to-modify-existing-unpushed-commits|How to modify existing, unpushed commits?]]
  * [[https://git-scm.com/book/en/v2/Git-Tools-Rewriting-History|7.6 Git Tools - Rewriting History]]
  * [[https://ihower.tw/blog/archives/2622|Git 版本控制系統(3) 還沒 push 前可以做的事]]

<code bash>
$ git commit --amend # 修改最近一個 commit 的訊息
</code>
====== 刪除提交 ======
  * git revert 和 git reset 作用方式不同。git reset 只用在私人分支，git revert 只用在公共分支。
    * [[https://www.atlassian.com/git/tutorials/resetting-checking-out-and-reverting|Reset, Checkout, and Revert]]
    * [[https://www.atlassian.com/git/tutorials/undoing-changes|Undoing Changes]]
    * [[http://stackoverflow.com/questions/4850717/how-to-cancel-a-local-git-commit|How to cancel a local git commit]]
    * [[http://stackoverflow.com/questions/927358/how-to-undo-last-commits-in-git|How to undo last commit(s) in Git?]]
    * [[http://stackoverflow.com/questions/1338728/delete-commits-from-a-branch-in-git|Delete commits from a branch in Git]]

<code bash>
$ git reset HEAD~1 # 刪除最近一個 commit，其內容會保留在當前的工作目錄。
# 修改被刪除的最近一個 commit 內容。
$ git commit -c ORIG_HEAD # 重新 commit 被刪除的最近一個 commit，沿用原本的 commit message。
$ git reset --hard HEAD~1 # 刪除最近一個 commit，不保留其內容。
</code>
====== 子模組 ======
  * [[https://git-scm.com/book/zh-tw/v1/Git-%E5%B7%A5%E5%85%B7-%E5%AD%90%E6%A8%A1%E7%B5%84-Submodules|6 Git 工具 - 子模組 (Submodules)]]
    * `git submodule update --init` 下載之後，進入 submodule 會發現它們不在各自的 master branch。這是因為基本上 parent repo 只用 commit 號來認這些 submodule。
    * [[http://josephj.com/entry.php?id=357|Git Submodule 的常見錯誤]]

  * [[https://yodalee.blogspot.com/2018/01/git-submodule.html|使用 git submodule 管理 project 所需的其他模組]]
  * [[https://blog.wu-boy.com/2011/09/introduction-to-git-submodule/|Git Submodule 介紹與使用]]


====== 發送補丁 ======
  * [[http://alblue.bandlem.com/2011/12/git-tip-of-week-patches-by-email.html|Git Tip of the Week: Patches by Email]]
  * [[https://git-scm.com/blog/2010/03/10/bundles.html|Git's Little Bundle of Joy]]
  * [[http://stackoverflow.com/questions/3635952/how-to-use-git-bundle-for-keeping-development-in-sync|How to use git-bundle for keeping development in sync?]]

<code bash>
$ git bundle create commits.bundle commit_id..master # commit_id 之後包含你想要打包的 commit。
# 透過 email 或是 usb 傳送給對方。
$ git remote add commits /path/to/commits.bundle # 添加來自 commmits.bundle 的 remote。
$ git pull commits dev # 如果對方是在分支 dev 打包 bundle，則指從分支 dev pull。  
</code>


====== Bisect ======
<code bash>
$ git clone git://git.qemu.org/qemu.git
# 开始 git bisect。
$ git bisect start
# 标记当前版本为错误。
$ git bisect bad
# 標記一個只知好的版本，git 會自動選出一個中間版本，重新開始測試。
$ git bisect good v1.0.1
# 測試通過，標記為 good，選下一個中間版本。如果失敗，標記成 bad，選下一個中間版本。
$ git bisect good
# 顯示引入錯誤的 commit 其內容。
$ git show 7b93fadf3a38d1ed65ea5536a52efc2772c6e3b8

  ... 定位到引入錯誤的 commit，修正 ...

# 返回到当前的 HEAD。
$ git bisect reset
</code>
  * [[http://crazycode.iteye.com/blog/311564|使用git bisect快速定位引入错误的版本]]
  * [[http://lists.gnu.org/archive/html/qemu-devel/2012-02/msg02856.html|[Qemu-devel] [PATCH] Fix dependency issue introduced by commit 7b93fadf3a38d1ed65ea5536a52efc2772c6e3b8]]
  * [[http://lists.gnu.org/archive/html/qemu-devel/2012-02/msg02917.html|[Qemu-devel] [PATCH v2] Fix dependency issue introduced by commit 7b93fadf3a38d1ed65ea5536a52efc2772c6e3b8]]
====== Submit Patch ======
<code bash>
# git clone git://repo.or.cz/qemu.git
$ git clone git://git.qemu.org/qemu.git
$ cd qemu
# 建立新的 branch，之後會自動生成 a 和 b 的 diff。
$ git checkout -b b

... 修改檔案 ...

# 生成單一 patch
$ git commit -a -m "exec.c: Remove useless comment" # 此訊息會是之後信件的 subject
# 生成多個 patch。google git split patch
$ git commit exec.c -m "exec.c: Make variable logfilename accessible from linux-user/main.c"
$ git commit linux-user/main.c -m "linux-user/main.c: Add option to user-mode emulation so that user can specify log file name"
$ git fetch origin
$ git rebase origin
# 產生單一 patch
$ git format-patch -s origin --stdout > ../b.patch
$ mutt -H b.patch
# 產生多個 patch。--cover-letter 會產生 patchset 的第一封信，應該用來描述 patchset 的大致用途。
$ git format-patch -s origin --cover-letter  -o tmp; cd tmp
# 書寫 patch set 的開頭第一封信，並依序填寫 patch set 的內文解釋 patch。
# --compose 內文為空，沒有任何跟 patchset 有關的東西，和 cover letter 不一樣。
# 可以直接用 vim 修改 patch，且之前修改的內容都會留下。
#
# 建議先改完，在 git send-email --annotate --suppress-from --to user@example.com * 一次送出。
#
$ git send-email --annotate --suppress-from --to user@example.com 0000-cover-letter.patch
Subject: [Qemu-trivial][PATCH 0/2] Add option to user-mode emulation so that user can specify log file name 

  QEMU user-mode's default log file name is "/tmp/qemu.log". In order to change
the log file name, user need to modify the source code then recompile QEMU. This
patchset allow user use "-D filename" option to specify the log file name.

Chen Wen-Ren (2):
  exec.c: Make variable logfilename accessible from linux-user/main.c
  linux-user/main.c: Add option to user-mode emulation so that user can
    specify log file name

 exec.c            |    2 +-
 linux-user/main.c |    8 ++++++++
 2 files changed, 9 insertions(+), 1 deletions(-)

--
1.7.3.5
</code>

<code bash>
# 會送到 gmail 草稿夾
$ git format-patch --attach --stdout origin | git imap-send
</code>

  * [[http://ariejan.net/2009/10/26/how-to-create-and-apply-a-patch-with-git/|How to create and apply a patch with Git]]
  * [[http://blog.longwin.com.tw/2009/05/git-send-patch-commit-use-email-2009/|Git 透過 Email 傳送 Patch / Commit]]
  * [[http://morefedora.blogspot.com/2009/02/configuring-git-send-email-to-use-gmail.html|Configuring git send-email to use Gmail SMTP]]
  * [[http://weylan.blog.edu.cn/2010/546263.html|git-sendmail 好方便]]
  * [[http://felipec.wordpress.com/2009/10/25/git-send-email-tricks/|git send-email tricks]]
  * [[http://people.debian.org.tw/~chihchun/2010/12/01/sending-patch-with-git-imap-send/|用 git-imap-send 送 patch]]
    * [[http://search.cpan.org/~pmakholm/Encode-IMAPUTF7-1.05/lib/Encode/IMAPUTF7.pm|Encode::IMAPUTF7 ]] 
  * [[http://webcache.googleusercontent.com/search?q=cache:uFhyPoLv9lkJ:blog.rmi.twbbs.org/2010/02/gmail-git-email-git-send-email-smtp.html+&cd=2&hl=zh-TW&ct=clnk|使用 gmail 做為 git-email (git-send-email) 的 smtp server]]
  * [[http://elinux.org/Git_usage#send-email|Git usage]]
  * [[http://oss.oracle.com/osswiki/GitRepositories|Git Repositories on oss.oracle.com]]
  * [[http://linux.die.net/man/1/git-format-patch|git-format-patch]]
  * [[http://wiki.qemu.org/Contribute/SubmitAPatch|SubmitAPatch]]

  * [[https://lists.gnu.org/archive/html/qemu-devel/2011-09/msg02786.html|[Qemu-devel] [PATCH] exec.c: Remove useless comment]]
  * [[https://lists.gnu.org/archive/html/qemu-trivial/2011-10/msg00059.html|[Qemu-trivial] [PATCH] exec.c: Remove useless comment
]]
    * [[http://lists.nongnu.org/archive/html/qemu-devel/2011-10/msg03163.html|Re
: [Qemu-devel] [Qemu-trivial] [PATCH] exec.c: Remove useless comment]]
    * [[http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg01025.html|Re: [Qemu-devel] [PATCH 0/6] Remove libqemu related stuff from QEMU source tree]]
    * [[http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg01549.html|[Qemu-devel] [PATCH 0/6 v2] Remove libqemu related stuff from QEMU source tree]]
    * [[http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg02038.html|[Qemu-devel] [PATCH v3 0/6] Remove libqemu related stuff from QEMU source tree]]
    * [[http://lists.nongnu.org/archive/html/qemu-trivial/2011-11/msg00036.html|[Qemu-trivial] [PATCH] linux-user/main.c: Add option to user-mode emulation so that user can specify log file name]]
    *  qemu-trivial@nongnu.org
  * [[http://lists.gnu.org/archive/html/qemu-devel/2012-05/msg01958.html|[Qemu-devel] Posting a patch?]]

  * [[http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg01989.html|[Qemu-devel] [PATCH v5 1.0] configure: build position independent executables across for x86 hosts]]
  * [[http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg00117.html|[Qemu-devel] [PATCH v4 0/4] -net bridge: rootless bridge support for qemu]]
    * 學怎麼寫 v? 的不同。
    * 單一 patch 在 "---" 後加上 v? 的說明。<code>
Signed-off-by: Avi Kivity <address@hidden>
---

v5: fix typos; only default enable for x86; mutually exclusive with -static

v4: say it's v4 and for 1.0

v3: detect toolchain support for PIE at configure time

v2: improve description to include relro
</code>
    * 多個 patch，在 cover letter 上加上 v? 的說明。<code>
v4:
 - Update has_vnet_hdr() to return bool
 - Update helper's main() to prevent errno clobbering
 - Let Kernel cleanup helper's file descriptors

Corey Bryant (4):
  Add basic version of bridge helper
  Add access control support to qemu bridge helper
  Add cap reduction support to enable use as SUID
  Add support for net bridge
</code>
====== Apply Patch ======
<code bash>
# 查看 patch 但不 apply
$ git apply --stat b.patch
 exec.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
# apply patch
$ git apply --check b.patch
# 保留 patch 的資訊
$ git am --signoff b.patch
$ git log
</code>
<code bash>
# 使用 mutt 把包含 patch 的 mail 存到 mbox，下 s。例如存到 qemu-patch。
$ git am --utf8 --signoff ../qemu-patch
cat: /z/tmp/chenwj/qemu/.git/rebase-apply/last: No such file or directory
previous rebase directory /z/tmp/chenwj/qemu/.git/rebase-apply still exists but mbox given.
$ git am --abort
$ git am --utf8 --signoff ../qemu-patch
</code>

  * [[http://osdir.com/ml/git/2009-09/msg01492.html|'git am' doubt]]
  * [[http://linux.yyz.us/git-howto.html|Kernel Hackers' Guide to git]]


====== 常用 Git 服務 ======
  * [[https://www.gerritcodereview.com/|Gerrit]]
    * rebase 保留舊有的 Changed-Id，就會維持在同一個 code review。
  * [[https://www.phacility.com/|Phabricator]]
===== GitHub =====
<note>建議邊閱讀邊實際操作。</note>
  * [[https://guides.github.com/activities/hello-world/|Hello World 10 minute read]]
    * [[https://help.github.com/articles/which-remote-url-should-i-use/|Which remote URL should I use?]]
      * 官方建議使用 HTTPS clone repository。如果不想重複輸入帳號密碼，請見 [[https://help.github.com/articles/caching-your-github-password-in-git|Caching your GitHub password in Git]]。<code bash>
$ git config --global credential.helper osxkeychain
</code>

  * [[http://hisham.hm/2016/01/01/how-to-make-a-pull-request-on-github-a-quick-tutorial/|How to make a pull request on GitHub - a quick tutorial]]
    * 利用 pull request 貢獻代碼到別人的 repository。
    * [[https://www.peterdavehello.org/2014/02/update_forked_repository/|更新從 GitHub 上 fork 出來的 repository (或是同步兩個不同 server 端的 repository)]]
      * 發起 pull request 要先 fork 別人的 repository。
    * [[https://gist.github.com/longtimeago/f7055aa4c3bba8a62197|How to squash commits in a GitHub pull request]]
      * 如果已經發送 pull request 的 commit 需要修改，一般會透過 squash 將更新的 commit 和原來已發送 pull request 的 commit 合併。流程如下:<code bash>
# 和上游同步
$ git fetch upstream
# 切換到自己的分支
$ git checkout b
$ git rebase -i upstream/master
# 修改後，透過 git rebase -i HEAD~2 squash commit
# 覆寫自己 GitHub 上的分支 b。之前已發送的 pull request 會自動更新。  
$ git push origin b -f
</code>

  * [[https://www.smashingmagazine.com/2014/08/build-blog-jekyll-github-pages/|Build A Blog With Jekyll And GitHub Pages]]
    * 透過網頁介面 commit ''_config.yml'' 觸發 GitHub 產生頁面。 
    * [[https://help.github.com/articles/what-is-github-pages/|What is GitHub Pages?]]

  * [[https://medium.com/@cwRichardKim/put-your-resume-pdf-on-a-website-that-updates-automatically-242ef7d023ec#.oyl0ieyod|Put your resume.pdf on a website that updates automatically]]
    * 將履歷放上 GitHub，統一維護。
    * gh-page 設定好之後，只需更新 master 分支上的履歷。

  * [[https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/|Adding an existing project to GitHub using the command line]]
    * 在 GitHub 上新建一個不含任何檔案的 repository，會跳出操作提示頁面。
===== GitLab =====
  * [[https://about.gitlab.com/|GitLab]]
    * [[https://www.youtube.com/watch?v=enMumwvLAug|Introduction to GitLab Workflow]]
    * [[https://about.gitlab.com/2016/10/25/gitlab-workflow-an-overview/|GitLab Workflow: An Overview]]
    * [[https://docs.gitlab.com/ce/workflow/README.html|Workflow - GitLab Document]]
    * 提供 code review, issue tracker 和 wiki。

流程：
  - 開 issue
  - 開 branch
  - git clone branch; git push; git push -f (類似 gerrit changed-id 的效果)
  - 送 merge request
===== Phabricator =====
<note>Phabricator 基本上一個 revision 就是一個 commit。如果當前任務需要多個 commit 完成，創建 dependent revision。</note>

  * [[https://medium.com/fcamels-notes/%E4%BD%BF%E7%94%A8-phabricaor-%E7%9A%84%E5%B7%A5%E4%BD%9C%E6%B5%81%E7%A8%8B-5247b04dd871|使用 Phabricator 的工作流程]]
  * [[https://willdemaine.ghost.io/a-simpler-phabricator-stacked-diff-workflow/|A Simpler Phabricator Stacked Diff Workflow]]
  * [[https://smacleod.ca/posts/commit-series-with-phabricator/|Commit Series with Phabricator]]
  * [[https://medium.com/@kurtisnusbaum/stacked-diffs-keeping-phabricator-diffs-small-d9964f4dcfa6| Stacked Diffs: Keeping Phabricator Diffs Small]]

  * 一個 branch，一個 commit，一個 review 單。<code bash>
# 依賴關係: master -> ref_abc -> fix_abc
(master)  $ git checkout -b ref_abc
(ref_abc) $ git commit
(ref_abc) $ git checkout -b fix_abc
(fix_abc) $ git commit
(fix_abc) $ git checkout ref_abc
(ref_abc) $ arc diff master      # D1
(ref_abc) $ git checkout fix_abc
(fix_abc) $ arc diff ref_abc     # D2
</code>
  * 更新 review 單。<code bash>
(master)  $ git checkout ref_abc
(ref_abc) $ git pull --rebase origin master
(ref_abc) $ git submodule update
(ref_abc) $ git commit -a --amend
(ref_abc) $ arc diff master --update D1
(ref_abc) $ git checkout fix_abc
(fix_abc) $ git pull --rebase . ref_abc
(fix_abc) $ git commit -a --amend
(fix_abc) $ arc diff ref_abc --update D2
</code>
  * approve 之後，由前往後依序合入代碼。<code bash>
(master)  $ git checkout ref_abc
(ref_abc) $ arc land --onto master --revision D1 --merge
(ref_abc) $ git checkout fix_abc
(fix_abc) $ arc land --onto master --revision D2 --merge
</code>

====== 外部連結 ======
  * [[http://stackoverflow.com/questions/115983/how-do-i-add-an-empty-directory-to-a-git-repository|How do I add an empty directory to a git repository]]
  * [[http://www.youtube.com/watch?v=j45cs5_nY2k|Contributing with Git]]
  * [[http://blog.longwin.com.tw/2009/01/how-send-code-into-open-source-project-diff-patch-2009/|好文: 如何將程式送給 Open Source 的 Project 與 diff / patch 使用]]
  * [[http://ihower.tw/blog/archives/6696/|Git 教育訓練課程投影片]]