如果存在，先將已有的ssh備份，或者將新建的ssh生成到另外的目錄下
   如果不存在，通過預設的引數直接生成ssh
   生成過程如下：
   $ssh-keygen -t rsa -C [email protected]（註冊github時的email）（注意空格）
    Generating public/private rsa key pair.
    Enter file in which to save the key (/Users/twer/.ssh/id_rsa): 
    Created directory '/Users/twer/.ssh'.
    Enter passphrase (empty for no passphrase): 
    Enter same passphrase again: 
    Your identification has been saved in /Users/twer/.ssh/id_rsa.
    Your public key has been saved in /Users/twer/.ssh/id_rsa.pub.
    The key fingerprint is:
    18:16:11:c9:01:6c:48:09:7f:27:c6:43:0d:7f:3f:84 
 
[email protected]
    The key's randomart image is:
    +--[ RSA 2048]----+
    |.o.++===         |
    |.ooo.+. .       |
    |  ..* = E .      |
    |   o = + o       |
    |      . S o      |
    |           .     |
    |                 |
    |                 |
    |                 |
   +-----------------+
 

3、 在github中新增ssh：

   登陸github，選擇Settings-->SSH Keys 新增ssh
   Title：[email protected]
   Key：開啟你生成的id_rsa.pub檔案，將其中內容拷貝至此（路徑在第2步）

4、測試SSH：

   $ssh [email protected]
   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)? **yes**
   Warning: Permanently added 'github.com,207.97.227.239' (RSA) to the list of known hosts.
   PTY allocation request failed on channel 0
   Hi xianfuying! You've successfully authenticated, but GitHub does not provide shell access.
            Connection to github.com closed.
   設定本地git個人資訊：
   $git config --global user.name "github使用者名稱"
   $git config --global user.email "註冊郵箱"
 

5、將原生代碼push到github

   先在github中建立Repository：
   https://github.com/ --> New Repository 輸入Repository資訊 projectName
   在本地建立程式碼庫：              
   $mkdir test   //建立一個資料夾作為local repositor
   $cd test     
   $vi test.txt  //建立一個檔案(程式碼？)
   $git add test.txt //將檔案新增至local repository
   $git init    //初始化local repository
   $git commit -m "first" //commit檔案 不能為空否則會出錯（“commit -a” 又沒有新增說明會出錯）
   git remote add origin https://github.com/使用者名稱/projectName.git 
   //定義遠端伺服器別名(origin可隨便取)但不能重複 若為重複錯誤 可rm別名重新定義：git remote rm origin
   $git push -u origin master//將本地資料push到github上

6、從github中pull程式碼：

  使用命令：
  $git pull https://github.com/使用者名稱/專案名  //將github上的程式碼pull到local repository中