$ uname –a # Display linux system information
$ uname –r # Display kernel release information (refer uname command in detail)
$ hostname # Show system host name
$ hostname -i # Display the IP address of the host (all options hostname)
$ uptime # Show how long system running + load (learn uptime command)
$ last reboot # Show system reboot history (more examples last command)
$ cat /etc/redhat_release # Show which version of redhat installed
$ date # Show the current date and time (options of date command)