CSCI 235 — Linux I

Getting started

This will be chaos. Your username is the same as your UNC Asheville email id. Your initial password is obtained by sticking the first four letters of your last name in front of the last four numbers of your student id number (the nine-digit number that starts with 93). For example, if my UNC Asheville ID was 930012345, my password would be Broc2345.

Expect this part to take a while.

Changing your password

Once you are in the window system, open up a browser window and a terminal session. You may need to click on the 3x3 array of dots in the lower-left corner to find the terminal app. If you are having problems and the instructor is helping others with the initial login, look for a Linux geek.

Use the program passwd to change your password. Unfortunately, there is no way to synchronize your UNCA password with your CSCI password.

Introduction to Linux

We’ll start by using one of the UNC Linux Guides.

Task I

Go to the UNIX/Linux: Getting Started guide. You can skip down to the section called “Interacting with the Shell”.

After you have read the “Getting Help” section, use the man command to figure out which flags to use with the ls command to get a recursive listing of all the files in your directory. There should be a lot.

Task II

Create a directory called csci235 and use the chmod command to make it readable only by you. Do all your work for this course in your csci235 directory. Also, create a symbolic link on the desktop to make it readable only by you. OK. Here is is below.

    pushd ~
    mkdir csci235
    chmod go-rwx csci235
    ls -lgd csci235
    ln -s ~/csci235 Desktop
    popd
  

On Ubuntu systems pico is really nano. Connect to your csci235 directory and use nano to create a file listing the computer science classes your have taken.

You should be using a real editor like emacs (yeah) or vim (boo). In spite of my decades of use of emacs, I suggest you use vim (sigh).

To learn a bit about vim (sigh), start up the vimtutor.

Task III

For some reason the link to the UNC intermediate tutorial is AWOL. So let’s move to the UNIX Tutorial for Beginnners at for the Electrical Engineering department at the University of Surrey.

Open up the tutorial on I/O redirection and pipes. Do the exercises. You must understand this to be a Unix geek.

Finally read about wildcards in 4th Surrey tutorial.

Remote login

We’ll start with command-line program ssh. By the way, if you have a Mac, ssh should already be installed. Under direction, do the following commands:

ssh-keygen -t rsa
ls -l .ssh
more .ssh/*
ssh USERID@www.cs.unca.edu
w
exit
pushd .ssh
ls -lt
cat ~/id_rsa.pub >> authorized_keys
popd
ls -lt
ssh www.cs.unca.edu
  

PuTTY is a popular remote login application that runs on both Linux and Windows. (Mac users should stick with ssh.)

Start the PuTTY application on your workstation. Connect to the computer www.cs.unca.edu at port 22, the secure SSH port.

You will probably find the default font size too small, so go back to the PuTTY configuration window and create a session called UNCA CSCI with a larger font and perhaps some fun colours. (Evidently, people in England mispel color.)

The final thing

Logout before leaving. If you don’t, the students in CSCI 182 will be very unhappy.