command -ubuntu

WC

-c, --bytes print the byte counts

-m, --chars print the character counts
-l, --lines print the newline counts
--files0-from=F read input from the files specified by
NUL-terminated names in file F;
If F is - then read names from standard input
-L, --max-line-length print the length of the longest line
-w, --words print the word counts
--help display this help and exit
--version output version information and exit

who | wc -l

#超级管理员

$普通管理员

tar cvpzf backup.tgz  /  权限备份

tar xvpzf 解压

Network configure     /etc/network/interfaces

auto eth0

iface eth0 inet static

address 10.0.0.100

netmask 255.255.255.0

gateway 10.0.0.1