UBUNTU TECH TIPS

To enable root user in UBUNTU
# sudo passwd

Sudo will prompt you for your password, and then ask you to supply a new password for root as shown below:
sudo password for username: user password
enter new UNIX password: password for root
retype new UNIX password: password for root

To disable root user
# sudo passwd -l root

To add or delete users
# adduser username
# deluser username

To add or delete group
# addgroup groupname
# delgroup groupname

To view directory space usage in human readable format
# du -sh /directory

To add or remove network interfaces
# vi /etc/network/interfaces

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
address 110.xxx.xx.xx
netmask 255.255.255.xxx
gateway 110.xxx.xx.xx

auto eth1
iface eth1 inet static
address 192.168.1.x
netmask 255.255.255.0
network 192.168.1.0

auto eth2
iface eth2 inet dhcp

## GUI PACKAGE MANAGEMENT TOOL
$ synaptic &

## TO REMOVE PACKAGES USING TERMINAL

For example remove package called mplayer, enter:
$ sudo apt-get remove mplayer



##To list all installed package
dpkg --list
dpkg --list | less
dpkg --list | grep -i 'squid3'


Remove package called squid3 along with all configuration files, enter:
$ sudo apt-get --purge remove squid3