Howto find out information about Unix System

Q. I’m trying to get basic information about UNIX system like logged in user, find out today’s date disk space and quota usage and so on. Can you list command name for me?

A. Try out following basic command to get information about UNIX or Linux systems

Task: Get the date and time

Display or set the system date and time, use:
$ date

Task: Find out more about my UNIX operating system

Print all system information, use:
$ uname -a

Task: Find out who logged in lately

Show listing of last 10 logged in users, use:
$ last -10

Task: Find name of my UNIX computer

Show or set the system’s host name, use:
$ hostname

See the disk space used

Report filesystem disk space usage, use:
$ df -k
On some system try
$ df -H

Find out user disk quota usage

Display disk quota usage / limits, use:
$ quota -v
$ quota user
$ quota group

Find out how much space all my files needs

Estimate file space usage, use:
$ du -k

Task: See who is logged on

Show who is logged on and what they are doing, use following command:
$ w
$ who
$ what