# date

# ls /usr/share/zoninfo/Asia

# mv /etc/localtime /etc/localtime_org

# ln -s /usr/share/zoneinfo/Asia/Seoul /etc/localtime

# date

# timedatectl

# cal

# cal 2023

# cal 2025

# cal

# clear

# history

# clear

# logname

# users

# who

# whoami

# logname

# users

# who

# uname

# uname -a

# uname -m

# uname -n

# uname -r

# uname -s

# uname -v

# hostname

# arch

# env

# echo Have a good time

# echo -e Have a god time. "\n" Nice good day.

# which echo

# which cp

# which mv

# ls /usr/bin

# history

# !25

# history -d 25

# history -c

# history

# !3

# history -d 5

# history -c

# su - root

# su - cskisa

# pwd

# ls -F

# ls -F /usr