CSCI 171 lab 1 (Jan. 12): intro to the labs

• Introduction to the CS laboratory
• Introduction to linux
• Useful commands
• Useful tools

Lab exercise:

1. Get your account information from the course instructor, read the rules of conduct regarding computing accounts, and follow the instructions on this web page to login to your CS account, open a web browser, open a command window, change your password, and log out.

2. Log back in with your new password and open a web browser and command window.

3. Read the "Introduction to linux" section and the "Useful commands" section below.

4. In your home directory, use the mkdir command to create a subdirectory named csci171, then use the ls command to check if it worked. (csci171 should appear in the list of files/directories if you succeeded.)

5. Once you have created your csci171 directory, use the cd command to move into that directory, then use the pwd command to check if it worked. (csci171 should be at the end of the path name if you succeeded.)

6. Still in your csci171 directory, use the mkdir command to create a subdirectory named lab1, and use the ls command to check if it worked.

7. Type in the command gedit to open the text editor.

   Now in the empty editor window type the following:

          #! /usr/bin/python
   
          print "hi!"
          

   Click on the "Save" command in the editor toolbar, using "hello.py" as the file name, and click on the "Save" button.

   Quit the editor (using File->Quit or click on the x in the upper right corner of the editor window.)

   Back in your terminal window, type the following command
   chmod u+x hello.py

   Now type in the command
   ./hello.py

   If successful, you should see
   hi!
   appear in the terminal window.

   Congrats! You have just successfully written and executed your first python program for the course!

Introduction to the CS laboratory

• Accounts:
  Computer science runs its own collection of linux machines, and each student in the course will be given an account on these machines.

  This account is completely seperate from any other VIU computing accounts you may have.

  In the labs on January 12th you will each be given your account userid (usually part of your surname and some initials) and a password, along with the departmental policies on use of computer accounts.

  It is important you read these policies and understand your responsibilities with respect to use of your account.

• The lab rooms:
  Initially, your account will work for the machines in lab 102 (in building 315).

  Later in the semester you will probably also be given access to the machines in lab 115 (across the hall from 102).

  To get into the lab rooms outside of regular class hours you will need a programmed card key.
  Instructions to set up your card key are given here.

• Logging in:
  When you first sit down at any of the machines you should see a window with typical login and password fields.

  Use the userid and password provided on the account sheet given to you by the course instructor.

  1. Enter your user id and hit enter

  2. Enter your password and hit enter
  When you are typing your password the cursor symbol won't move in the password box, so it looks like nothing is happening. Enter your password anyway, and hit return.

• Opening a web browser (ice weasel):
  • Under the Applications menu in the upper left corner of the screen, select Internet, then out of the list of choices it gives you select Iceweasel Web browser

  • Once the browser opens, enter the url
    http://csciun1.mala.bc.ca:8080/~wesselsd

  • Click on the CSCI 171 link

  • Click on the Labs link

  • Click on the Lab 1: Jan. 12 link to get the rest of the instructions for this week's lab.

• Opening a command window (terminal):
  Many of the things we do this semester will require us to type in linux commands.

  To do so, we need to open a command shell (a.k.a. command window, terminal window, etc).

  To open a command window:

  • Click on the Applications menu in the upper left corner of the screen.
  • Select the Accessories submenu.
  • Select the Terminal option from that menu.
  This should open a new window in which you can type linux commands.

• Changing your password:
  Once you have opened a command window (see the step above), you can change your password by typing in the command yppasswd

  This will prompt you to enter your old password, then (assuming you entered your old password correctly) it will prompt you for a new password and will ask you to retype your new password to confirm it.

  This will update your password on all CSCI machines.

• Logging out:
  You must remember to log out whenever you leave the lab. DO NOT LEAVE YOUR ACCOUNT LOGGED IN AND LOCKED To log out:
  • Click on the Desktop menu in the upper left corner of the screen.
  • Select the Log out option at the bottom of the list of options.
  • When it opens a confirmation window, select the Log Out option.

• Forgotten login ids and passwords:
  If you have forgotten your login id I can look that up for you.

  If you have forgotten your password, please go to the IT Help Desk on the ground floor of the library and present your student card, and they will be able to send a request to IT services that automatically resets your password.

Introduction to linux and bash

The machines in lab 102 connect you to a (shared) linux server named csciun1.mala.bc.ca.

CSCI students and faculty can each connect to this server from a variety of locations (including connecting from home).

Each person has their own account, with its own directory (folder) of files and subdirectories.

Whenever you log in to the server you will automatically begin in your account's directory.

You have the ability to create and edit files within your account's directory, as well as create other subdirectories inside it to keep your files organized. (It can get awfully cluttered if you keep all of your files in just one big collection.)

Aside: Whenever you type in a command in a terminal window, or whenever you click/doubleclick on items in the visual interface, your commands get interpretted by a command shell. The particular command interpretter being used on csciun1 is called bash.

Useful tools

• Gedit: a nice visual editor, found under
  Applications->Debian->Apps->Editors->Gedit
• Blender: an animation tool, found under
  Applications->Debian->Apps->Graphics->Blender (windowed) or
  Applications->Graphics->Blender 3D modeller
• The GIMP: an image editor, found under
  Applications->Debian->Apps->Graphics->The GIMP or
  Applications->Graphics->The GIMP
• Python: an interpretter, found under
  Debian->Apps->Programming->Python

Useful commands

• Commands for today's lab:
  • cd (move to a different directory)
    to move from the current directory to a subdirectory use cd subdirectoryname
    to move straight to your home directory use just cd
    to move from a subdirectory to it's "parent" directory use cd ..
  • chmod (change access permissions)
    by default, you should have permission to read and edit your own files
    to make a file executable (e.g. python files that you want to be able to run) use the command
    chmod u+x filename
    (then to actually run/execute the file use the command ./filename
  • gedit (opens the gedit editor)
    To open/edit a specific file use the command
    gedit filename
  • ls (list the current directory contents)
    To list the contents of the current directory simply type ls
    To list the contents of a subdirectory type ls subdirectoryname
    To list the contents of the parent directory type ls ..
  • mkdir (create a new directory)
    To create a new subdirectory type the command
    mkdir subdirectoryname
  • pwd (look up your current location)
    To see which directory you are currently in, type pwd (this will show the complete path from the root of the server's file system through to your current location).

• More linux commands:
  • ... I'll expand this as we encounter new commands ...