How to send a message to another user

To send a message to another user logged in the system,type


$ write username
(your message) ctrl+d 

How to stop receving messages from other user's

To stop receving messages from other user's

   
    $ mesg n


To allow messages from other user,type


    $ mesg y

How to display and use the last command you entered in your system

To display and use the last command you entered


    $ !!

How to know the details of CPU information

To know the information about the CPU,type


$ cat /proc/cpuinfo

Example is shown below:

How to show the details of hardware system components

To show the details of hardware system components,type


$ dmidecode -q


* Dmidecode means DMI table decoder. It contains a description of
system's hardware components and other useful information such
as serial number and BIOS version. To get the details of the
system components,you have to be a superuser. so type "sudo"
in-front of the command. Example is shown below

How to display PCI devices in your system

To get the details of PCI device, type


$ lspci -tv


example is shown below,

How to show USB devices in your system

To show USB devices,type


$ lsusb -tv


* lsusb is a utility to show the usb devices details ,example is
show below