本文中的最初作為例子的開原始碼庫smartdevicelink是一個車聯網真實的開原始碼庫，並且已經在量產車中有使用，歡迎有能力且有興趣的開發者參與，也可以聯絡我。不過發現之前發表文章後有哥們在上面誤操作，導致別的開發人員的正常pull request出現問題! 基於擔心可能別人也這樣操作，所以改為GitHub自身提供的一個例子。

引言：

隨著越來越多的網際網路企業宣佈自己在GitHub上開源專案，越來越多的開發人員可以參與進來開發，貢獻自己的一份力量。但是這樣由於大家互不謀面可能溝通交流，寫程式碼的方式，思維都會不一樣，所以需要一系列約束來遵守，最主要的就是貢獻程式碼時會有很多人同時開發的情況，這樣需要經常同步上游倉庫到自己本地倉庫和自己的遠端伺服器中。

準備：

1. 建立自己的GitHub賬號

https:github.com

2. Fork一個你準備參與開發的程式碼庫

GitHub上專門有一個供大家練習的Repository

這樣在自己的GitHub倉庫中就會有該程式碼庫：

3. Clone 到你本地

$git clone https://github.com/<user>/Spoon_Knife.git


4.新增遠端倉庫

$cd Spoon_Knife
$git remote -v
#git remote 可以檢視我們配置了那些遠端倉庫伺服器,並列出簡寫
#-v 可以幫助檢視遠端倉庫伺服器相對應的URL
 

origin https://github.com/<user>/Spoon_Knife.git(fetch)
origin https://github.com/<user>/Spoon_Knife.git(push)
$git remote add upstream https://octocate/Spoon_Knife
#git remote add <shortname> <url> 
#可以新增一個新的遠端Git倉庫，同時制定自定義的簡寫名稱
$git remote -v
origin https://github.com/<user>/Spoon_Knife.git
 
(fetch)
origin https://github.com/<user>/Spoon_Knife.git(push)
upstream    https://github.com/smartdevicelink/Spoon_Knife.git(fetch)
upstream    https://github.com/smartdevicelink/Spoon_Knife.git(push)

參與開發

一般的開原始碼庫，都有master分支和develop分支，master分支比較穩定，用來發布。develop分支一般用來開發。
強烈建議參與開發前每個開發者都仔細看一下程式碼庫中的CONTRIBUTING.md檔案，這樣會省很多沒必要的溝通，也會對該開源專案的要求做一個簡單的瞭解。
如果想新增一個新的需求，則可以基於原來程式碼的develop分支新建一個feature分支
如果發現了某個問題，並想解決這個問題，則應先提出issue,然後基於develop分支新建一個hotfix分支

$git checkout develop
$git checkout -b newFeature develop
$git checkout -b hotfix_bug# develop

然後在新建的分支上修改程式碼

同步：

由於開源的專案，會有很多人同時參與開發，所以需要經常同步其他人的開發。從遠端上游（upstream）倉庫同步程式碼到本地和自己fork來的GitHub倉庫中。需要三步：

1. Fetch 上游倉庫的新的提交

$git fetch upstream

會看到比較詳細的輸出資訊，從遠端倉庫拉取其新的分支和各自的提交，儲存到本地倉庫。
可以通過以下命令檢視本地的所有分支：

$git branch -va
* develop                                                  71493a0 Merge pull request #409 from LuxoftSDL/fix/Use_AppName_if_VR_or_TTS_synonyms_Empty_in_QueryApps
  master                                                   e76f8e7 Merge pull request #404 from smartdevicelink/hotfix/fix_pt_sendMessagetoSDK
  release/4.0.0                                            4d6cf97 Merge pull request #220 from LuxoftSDL/hotfix/SystemRequest_crash_sdl4.0
  remotes/origin/HEAD                                      -> origin/master
  remotes/origin/UPS-release                               4d00dc0 Merge branch 'hotfix/error-in-PI' into UPS-release
  remotes/origin/develop                                   71493a0 Merge pull request #409 from LuxoftSDL/fix/Use_AppName_if_VR_or_TTS_synonyms_Empty_in_QueryApps
  remotes/origin/feature/experimental/remote_control       61393c8 HMI Get URls Update
  remotes/origin/hotfix/change-device-info-to-string       d7f3cc3 Changed device_info id to string and mac_address
  remotes/origin/hotfix/cla                                a80368a Added instructions to sign CLA
  remotes/origin/hotfix/get_urls                           6e304f2 Get Urls Fix
  remotes/origin/hotfix/hybrid_service_to_mobile           9429759 Send hybrid service 0x0F if outgoing message has binary data
  remotes/origin/hotfix/local_pt_update                    44da661 Policy Table Update HMI Button
  remotes/origin/master                                    e76f8e7 Merge pull request #404 from smartdevicelink/hotfix/fix_pt_sendMessagetoSDK
  remotes/origin/release/4.0.0                             4d6cf97 Merge pull request #220 from LuxoftSDL/hotfix/SystemRequest_crash_sdl4.0
  remotes/upstream/UPS-release                             4d00dc0 Merge branch 'hotfix/error-in-PI' into UPS-release
  remotes/upstream/develop                                 71493a0 Merge pull request #409 from LuxoftSDL/fix/Use_AppName_if_VR_or_TTS_synonyms_Empty_in_QueryApps
  remotes/upstream/feature/experimental/remote_control     61393c8 HMI Get URls Update
  remotes/upstream/hotfix/bt_device_scanner_leak           36ba4ad Fixes #314     

2. Merge從上游倉庫拉取的變更

比如我們要合併master分支

$git checkout master
Switched to branch 'master'
Your branch is up-to-date with 'origin/master'.
$git merge upstream/master
Updating e76f8e7..6808a52
Fast-forward
 .travis.yml                                                                          |  15 ++
 README.md                                                                            |   4 +-
 src/components/application_manager/CMakeLists.txt                                    |   2 +
 .../application_manager/include/application_manager/application_manager_impl.h       |   5 +
 .../include/application_manager/commands/hmi/dial_number_request.h                   |  75 +++++++
 .../include/application_manager/commands/hmi/dial_number_response.h                  |  76 +++++++
 .../include/application_manager/commands/mobile/dial_number_request.h                |  27 ++-
 .../include/application_manager/commands/mobile/dial_number_response.h               |  72 ++++++
 src/components/application_manager/include/application_manager/smart_object_keys.h   |   1 +
 src/components/application_manager/src/application_manager_impl.cc                   |  10 +-
 .../application_manager/src/commands/hmi/button_get_capabilities_response.cc         |   8 +
 src/components/application_manager/src/commands/hmi/dial_number_request.cc           |  57 +++++
 src/components/application_manager/src/commands/hmi/dial_number_response.cc          |  57 +++++
 src/components/application_manager/src/commands/mobile/dial_number_request.cc        |  96 +++++++-
 src/components/application_manager/src/commands/mobile/dial_number_response.cc       |  53 +++++
 .../application_manager/src/commands/mobile/register_app_interface_request.cc        |  21 +-
 src/components/application_manager/src/commands/mobile/slider_request.cc             |   3 +-
 src/components/application_manager/src/commands/mobile/system_request.cc             | 489 +++++++++++++++++++++++++++++++++++------
 src/components/application_manager/src/hmi_command_factory.cc                        |  10 +
 src/components/application_manager/src/message_helper.cc                             |   1 -
 src/components/application_manager/src/mobile_command_factory.cc                     |  11 +
 .../connection_handler/include/connection_handler/connection_handler_impl.h          |   5 +-
 src/components/connection_handler/src/connection_handler_impl.cc                     |  21 +-
 src/components/interfaces/HMI_API.xml                                                |  14 ++
 src/components/interfaces/MOBILE_API.xml                                             | 144 ++++++------
 src/components/policy/src/policy/src/cache_manager.cc                                |  10 +
 26 files changed, 1108 insertions(+), 179 deletions(-)
 create mode 100644 .travis.yml
 create mode 100644 src/components/application_manager/include/application_manager/commands/hmi/dial_number_request.h
 create mode 100644 src/components/application_manager/include/application_manager/commands/hmi/dial_number_response.h
 create mode 100644 src/components/application_manager/include/application_manager/commands/mobile/dial_number_response.h
 create mode 100644 src/components/application_manager/src/commands/hmi/dial_number_request.cc
 create mode 100644 src/components/application_manager/src/commands/hmi/dial_number_response.cc
 create mode 100644 src/components/application_manager/src/commands/mobile/dial_number_response.c

如果本地沒有獨特的提交，git會自動fast-forward.

3. Push 本地更新到自己的遠端伺服器上

$git push origin master
Username for 'https://github.com': 
Password for 'https://[email protected]': 
Total 0 (delta 0), reused 0 (delta 0)
To https://github.com/user/Spoon_Knife.git
   98b34b9..6808a52  master -> master