startx
ctrl+alt+f1~7
passwd
passwd root
passwd user1
ls
ls -l
ls --all
ls -a
ls -al
cp install.log /tmp
passwd -S user1
useradd user2
passwd --status user2
date --help
date -s 12:00
date +%T
date +%D%T
cal
cal 8 2013
cal 2013 > 2013calendar
cat 2006calendar
whatis
<command> --help
man and info
/usr/share/doc/
redhat documentation
whatis ls
whatis cal
date --help
man 1 passwd
man 5 passwd
man 8 lvm
man -k passwd
info ls
n/p/u
s[string]