switch to root : sudo su、su root、sudo -s
switch to users : su god(user name)
set root password : sudo passwd root
check out kernel version : uname -r
generate 'config.gz' file(the compressed package of '.config') : modprobe configs
check the current path: pwd
enter current user root directory: cd ~
check thread: top
check process: ps
kill process: kill <process number>
check network information: ifconfig
request URL: curl
output the last part of files: tail -f
print the value of environment: echo $PATH
list all installed software: dpkg -l
config network: ifconfig
display or manipulate a disk partition table: fdisk
check mount status: df
exit current shell: exit
open terminal: ctrl+alt+t
close terminal: ctrl+d
exit current thread: ctrl+c
copy: ctrl+insert
paste: shift+insert