linux command

linux command about file and directory
cat
chmod 755(rwxr-xr-x)  r-4 w-2 x-1
chown
clear
file
find
grep
ln
locate
ls
mkdir
pwd
rm
touch
vi
which

linux command about file system
df
mount
umount

linux command about system status
reboot
halt
dmesg
uptime

linux command about user administration
useradd
passwd
userdel
groupadd
groupdel
su
whoami

pipe symbol
more
less