NamHuy

add delete and switch user in ubuntu by command lines

First, I want to add a user. So how to do it?

+ To add user:

sudo adduser <username>

to add password for your user

sudo passwd <username>

+ How can i switch from one user to another one? In this example, i want to switch from one user to another one.

su <username>

and type in your password to login

after that, you will be at a ‘$’ prompt. type:

bash

to get to a normal prompt.

+ How can I delete a user?

sudo userdel <username>

Terminal or shell command to shutdown or reboot Ubuntu Linux

So how do you shutdown or reboot Ubuntu Linux from a terminal or a shell prompt? If GUI is working you can always click on a Quit button. If GUI is not working or if you are working remotely over ssh type the following command:

To shutdown / poweroff Ubuntu Linux

Type the command:

sudo halt

OR

sudo shutdown -h now

OR

sudo shutdown -r now

OR

 sudo init 6

To reboot Ubuntu Linux

Type the command:

sudo reboot

More information can be found about these two commands by typing following commands (man page):

man reboot
man shutdown

Ubuntu Linux enable telnet service

What is telnet?

Telnet is a user command and an underlying TCP/IP protocol for accessing remote computers. Through Telnet, an administrator or another user can access someone else’s computer remotely. On the Web, HTTP and FTP protocols allow you to request specific files from remote computers, but not to actually be logged on as a user of that computer. With Telnet, you log on as a regular user with whatever privileges you may have been granted to the specific application and data on that computer.

A Telnet command request looks like this (the computer name is made-up):

telnet namhuy.org

The result of this request would be an invitation to log on with a userid and a prompt for a password. If accepted, you would be logged on like any user who used this computer every day.

Telnet is most likely to be used by program developers and anyone who has a need to use specific applications or data located at a particular host computer.

Install telnetd server

$ sudo apt-get install telnetd

Restart inetd service:

$ sudo /etc/init.d/openbsd-inetd restart

You should now be able to telnet to the server from Windows or Linux desktop system to Ubentu Linux telnet server. Type the following command to connect to Telnet server:

$ telnet ubentu-linux-server-ip
$ telnet 192.168.1.200
$ telnet ubentu.mydomain.com

CVS server on Ubuntu

Install CVS files:
sudo apt-get install cvs

Install the CVS server:
sudo apt-get install cvsd

When prompted in the cvsd installation process for Repository, type in “/cvsrepo”.

Now that the cvsd installation in complete goto /var/lib/cvsd
or seeking for a change(or if there is a new version of cvs updated):

sudo cvsd-buildroot /var/lib/cvsd
If the folder cvsrepo does not exist, then create it ..
sudo mkdir cvsrepo
sudo chown -R cvsd:cvsd cvsrepo

and then initilize the repository
sudo cvs -d /var/lib/cvsd/cvsrepo init
create a user and password
sudo cvsd-passwd /var/lib/cvsd/cvsrepo +username
sudo vi //var/lib/cvsd/cvsrepo/CVSROOT/config
Change “SystemAuto=no”

Test

cvs -d :pserver:username@localhost:/cvsrepo login

cvs -d :pserver:username@localhost:/cvsrepo checkout .

Auto login in Ubuntu

I know that I’m the only user in my system and no one else will have access to it. I don’t see a point to have a login screen. With Windows, I know we can set to auto login using a userid. I was searching for similar thing in Ubuntu. Found one

Go to terminal and type “sudo gdmsetup”. You will get login window preferences. Select Security tab; check “Enable automatic Login” and select the user. You are done! Simple ha? But why there is no shortcut in the