1.    sudo !!
repeat run above command by root account

2.python -m SimpleHTTPServer
Set up a simple web server by use python,you can interview through http://$HOSTNAME:8000

3. :w !sudo tee %
No need previlege to save file into vim

4. cd -
change the directory to last time view,

note: cd

when you direct into cd ,you will return the user home directory

5. ^foo^bar
replace the previous in the command among "foo" to bar and run

6. cp filename{,.bak}

backup or copy file rapid

7. mtr google.com

this command assemble traceroute and ping

8. !whatever:p

  1. mtr google.com 
  2. zhicai@zhicai:~$ !mtr:p 
  3. mtr google.com 

Search the history command,but not execute
note: ctrl + r  is search and execute

9. $ssh-copy-id user@host
copy ssh keys to user@host,so you can login without password

10. ffmpeg -f x11grab -s wxga -r 25 -i :0.0 -sameq /tmp/out.mpg
recording the desktop to video,
above all,install ffmeg:sudo apt-get install ffmpeg