clone 代碼到本地：
?git clone git鏈接
# Clever @ clever in~/Downloads/common on git:master o [11:33:05]
$ git status
On branch master
Your branch isup-to-date with 'origin/master'.
nothing to commit,working tree clean
# Clever @ clever in~/Downloads/common on git:master o [11:33:16]
$ git checkout dev
Branch dev set up totrack remote branch dev from origin.
Switched to a newbranch 'dev'
取回遠(yuǎn)程主機(jī)某個(gè)分支的更新奋刽，再與本地的指定分支合并
index暫存區(qū)
