Maintenance of Servers in Research Group

This is a guide mostly based on Ubuntu20.0.

Table of contents
  1. 1. Create Users
    1. Normal Users
    2. Super Users(Administrators)
    3. Bug Fix
  2. 2. Install Softwares
    1. Edit .bashrc
  3. 3. Change Hostname of A Server

1. Create Users

This is only a tutorial for one server. The guide for adding users in a computer group is here.

Normal Users 

sudo adduser peter     # Add a user with the name peter
sudo deluser peter     # Delete the user with the name peter
sudo deluser --remove-home peter   # Delete the user peter and remove '/home/peter' directory

Super Users(Administrators)

After adding a user, one can make it a super user.

sudo vi /etc/sudoers

And then add the following sentence under root ALL=(ALL:ALL) ALL in the sudoers file.

peter ALL=(ALL:ALL) ALL

Bug Fix

If other users can visit your personal files, change the permission of main directory.

  chmod -R o-rwx ~

2. Install Softwares

Edit .bashrc

  • After the software is installed, one can edit the .bashrc file to export the path. 
    sudo vim ~/.bashrc

    and add the following sentence to the end of the .bahsrc file.

    export PATH=$PATH:/***/julia-1.6.1-linux-x86_64/julia-1.6.1/bin
# This is an example for julia.
# *** is the Absolute Path of the 'bin' directory.

    Save changes by pressing ESC,:wq! in turns. And source the .bashrc file.

    source ~/.bashrc
  • Change the color scheme of the terminal Add the following sentence to .bashrc file. 
      PS1='${debian_chroot:+($debian_chroot)}[\d \t]\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '

    where ${debian_chroot:+($debian_chroot)} is meaningless.

The main body is \u@\h:\w\$ where \u means username, \h means hostname and \w means the working directory. [\d \t] stands for day and time.

Color setting: \[\033[XXm\] and XX is the code for the chosen color.

Color Code Color Code
Default 00 Yellow 33
Black 30 Blue 34
Red 31 Purple 35
Green 32 Cyan 36

3. Change Hostname of A Server 

sudo vi /etc/hostname # Change a new hostname
sudo vi /etc/hosts
127.0.1.1 newhostname # If only the hostname in /etc/hostname is changed, there would be a warning.

Table of contents