print work directory: $ pwd
disk free: $ df
change owner: $ chown
change group: $ chgrp
change mode: $ chmod
$ timedatectl
local$ tar zcvf name.tar.gz directory 压缩
local$ scp localfile user@ip:~/
To copy file from remote server: scp username@remote:/file/to/send /where/to/put
$tar zxvf name.tar.gz 解压缩
To print run-level: $systemctl get-default
To print system version: $cat /etc/redhat-release