五、Github的使用（1）

29、公私鑰的創建于配置github
為了在本地更好的操作遠程倉庫，可以在本地與遠程倉庫之間配置公私鑰連接，首先可以查看本地是否有公私鑰，如果沒有可以使用以下命令生成。

$ ls ~/.ssh/       #查看是否存在公私鑰
id_rsa  id_rsa.pub  known_hosts

ssh-keygen -t rsa -b 4096 -C "your_email@example.com"   #如果不存在可使用該命令生成

生成公私鑰后，將公鑰配置到github上。點擊頭像，進入Your Profile->SSH and GPG Keys即可進入配置公鑰界面

30.在GitHub上創建個人倉庫
點擊Create a repository鏈接

創建選項界面

創建成功后界面

31.把本地倉庫同步到GitHub
首先將github的倉庫地址配置到本地，可以在箭頭指示的地方獲取倉庫的地址

$ git remote -v
zhineng file:///d/git_learning/.git (fetch)
zhineng file:///d/git_learning/.git (push)

$ git remote add github git@github.com:embedlinux/git_learning.git

$ git remote -v
github  git@github.com:embedlinux/git_learning.git (fetch)
github  git@github.com:embedlinux/git_learning.git (push)
zhineng file:///d/git_learning/.git (fetch)
zhineng file:///d/git_learning/.git (push)

將本地文件推送到github上，此時可以知道Jone和temp分支push成功，而master失敗

$ git push github --all
Counting objects: 16, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (9/9), done.
Writing objects: 100% (16/16), 1.29 KiB | 77.00 KiB/s, done.
Total 16 (delta 2), reused 0 (delta 0)
To github.com:embedlinux/git_learning.git
 * [new branch]      Jone -> Jone
 * [new branch]      temp -> temp
 ! [rejected]        master -> master (fetch first)
error: failed to push some refs to 'git@github.com:embedlinux/git_learning.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

此時由于github上和本地的master分支發生沖突，因此需要merge

$ git fetch github master     #獲取遠程master分支
remote: Enumerating objects: 3, done.
remote: Counting objects: 100% (3/3), done.
remote: Compressing objects: 100% (2/2), done.
remote: Total 3 (delta 0), reused 0 (delta 0), pack-reused 0
Unpacking objects: 100% (3/3), done.
From github.com:embedlinux/git_learning
 * branch            master     -> FETCH_HEAD
 * [new branch]      master     -> github/master

$ git checkout master    #本地切換到master分支
Switched to branch 'master'

$ git branch -av
  Jone                  f0b5fe2 Add a file
* master                e0326fb Merge three commits
  temp                  b0fc955 Merge three commits
  remotes/github/Jone   f0b5fe2 Add a file
  remotes/github/master 831e37e Initial commit
  remotes/github/temp   b0fc955 Merge three commits
  remotes/zhineng/Jone  f0b5fe2 Add a file

$ git merge github/master     
fatal: refusing to merge unrelated histories

$ git merge --allow-unrelated-histories github/master    #合并遠程分支
Merge made by the 'recursive' strategy.
 LICENSE | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 LICENSE

$ git push github master     #再次push到github上，成功
Counting objects: 2, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (2/2), 373 bytes | 186.00 KiB/s, done.
Total 2 (delta 0), reused 0 (delta 0)
To github.com:embedlinux/git_learning.git
   831e37e..707f0f8  master -> master

32.不同人修改了不同文件如何處理
當不同的人工作在同一個branch，但是修改的是不同文件時，此時可以使用merge命令對文件進行更新。例如，當前在遠程修改了Jone分支的read1.txt文件。

在本地修改"second.txt"文件

$ git checkout Jone
Switched to branch 'Jone'
Your branch is up to date with 'zhineng/Jone'.

$ echo "Update the file " >> second.txt

$ git add .

$ git commit -m"Update second file"
[Jone 568a695] Update second file
 1 file changed, 1 insertion(+)

$ git push github Jone                             #此時由于本地文件與遠程不是同一個commit,出現問題
To github.com:embedlinux/git_learning.git
 ! [rejected]        Jone -> Jone (fetch first)
error: failed to push some refs to 'git@github.com:embedlinux/git_learning.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

$ git fetch github

$ git branch -av
* Jone                  568a695 [behind 2] Update second file
  master                707f0f8 Merge remote-tracking branch 'github/master'
  temp                  b0fc955 Merge three commits
  remotes/github/Jone   139cca2 Update read1.txt
  remotes/github/master 707f0f8 Merge remote-tracking branch 'github/master'
  remotes/github/temp   b0fc955 Merge three commits
  remotes/zhineng/Jone  0b88b5a Merge remote-tracking branch 'github/Jone' into Jone

$ git merge  remotes/github/Jone
error: Your local changes to the following files would be overwritten by merge:
        read1.txt
Please commit your changes or stash them before you merge.
Aborting

$ git merge  remotes/github/Jone
Merge made by the 'recursive' strategy.

$ git push github
Counting objects: 6, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (5/5), done.
Writing objects: 100% (6/6), 624 bytes | 156.00 KiB/s, done.
Total 6 (delta 3), reused 0 (delta 0)
To github.com:embedlinux/git_learning.git
   139cca2..00233dd  Jone -> Jone

33.不同人修改了同文件的同區域如何處理
當在開發中，不同工作人員對同一個文件的相同區域做了修改時，此時git進行merge就會發生錯誤，需要手工進行merge，確定需要保留的內容。首先遠程修改first1.md文件。

$ echo "Update the file on local" >> first.md     #本地也修改該文件

$ git  commit -am"Update first.md"
[Jone b6870f1] Update first.md
 1 file changed, 1 insertion(+)

$ git fetch github                      #獲取遠程倉庫
remote: Enumerating objects: 5, done.
remote: Counting objects: 100% (5/5), done.
remote: Compressing objects: 100% (3/3), done.
remote: Total 3 (delta 1), reused 0 (delta 0), pack-reused 0
Unpacking objects: 100% (3/3), done.
From github.com:embedlinux/git_learning
   00233dd..c87da97  Jone       -> github/Jone

$ git branch -av
* Jone                  b6870f1 [ahead 3, behind 1] Update first.md
  master                707f0f8 Merge remote-tracking branch 'github/master'
  temp                  b0fc955 Merge three commits
  remotes/github/Jone   c87da97 Update first.md
  remotes/github/master 707f0f8 Merge remote-tracking branch 'github/master'
  remotes/github/temp   b0fc955 Merge three commits
  remotes/zhineng/Jone  0b88b5a Merge remote-tracking branch 'github/Jone' into Jone

$ git merge c87da97     #由于遠程和本地修改相同文件，此時無法merge
Auto-merging first.md
CONFLICT (content): Merge conflict in first.md
Automatic merge failed; fix conflicts and then commit the result.

$ vim first.md    #手工修改沖突文件

修改前

修改后，同時保留遠程和本地的修改

$ git commit -am"Merge conflict file"     #再次提交
[Jone c2568ff] Merge conflict file

$ git push github --all             #push成功
Counting objects: 6, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (5/5), done.
Writing objects: 100% (6/6), 601 bytes | 150.00 KiB/s, done.
Total 6 (delta 2), reused 0 (delta 0)
To github.com:embedlinux/git_learning.git
   c87da97..c2568ff  Jone -> Jone