???????????
??????-->????
????i: ??????????????????棬??????????
????a: ??????????????????棬??????????
????o: ????????????е??·????????У?????????????
????I??????????????е????????????????
????A??????????????е???β????????????
????O??????????????е???????????У???????????
????????-->????ESC
??????-->??У? ??
???????-->????  ESC?? ESC
????#vi +3 /etc/......?????????
?????????????????
????:q  ???
????:wq ???沢???
????:q! ?????沢???
????:w ????
????:w! ??б???
????:wq --> :x
???????????????
????ZZ: ???沢???
???????????? h:??  l???? j:??  k????
????#h: ???#?????
????w: ?????????????????
????e: ??????????????????β
????b: ?????????????????????
?????????????
????0: ????
????^: ????????????????
????$: ??β
????#dd: ????????????????????????#??
????u?????????ε??????
????????u??????????????n?α?????
????#u: ????????#?α?????
????????????γ?????????Ctrl+r
???????????/etc/yum.repos.d/server.repo????е?ftp://instructor.example.com/pub?滻?http://172.16.0.1/yum
????%s/ftp://instructor.example.com/pub/http://172.16.0.1/yum/g
????%s@ftp://instructor.example.com/pub@http://172.16.0.1/yum@g
?????????????к?      :set nu    /   :set nonu