$ uname –a ⇒ Display linux system information
$ uname –r ⇒ Display kernel release information
$ cat /etc/redhat_release ⇒ Show which version of redhat installed
$ uptime ⇒ Show how long system running + load
$ hostname ⇒ Show system host name
$ hostname -A ⇒ Show system long name (FQDN)
$ hostname -i ⇒ Display the IP address of the host
$ hostname -I ⇒ Display ALL IP addresses of the host
$ last reboot ⇒ Show system reboot history
$ date ⇒ Show the current date and time
$ cal ⇒ Show this month calendar
$ w ⇒ Display who is online
$ whoami ⇒ Who you are logged in as