Lab 1: Intro to UNIX

For the TA
- Tasks:

Introduction

Beginning of the lab: login

As students come in, they should try to login:

If this is their first lab login, students will see a dialog asking which desktop to use (Java/Gnome or CDE).
They should pick the first (Java/Gnome).

Common login problem:

The MathCS system fails to recognize the login/passwd pair....
A likely cause is the fact that the student has never change his/her password (this fails to propagate the LDAP authentication information from the Emory account to the MathCS LDAP server)
Fix:

If a student fails to login, he should try a different machine.
If even that fails, the TA's should note the ID's of student.
The TA should also note if any machines aren't working (check the cables, only reboot as a last resort).
Call 7-3333 (from the phone in the lab) and ask if someone can come down to help if some student cannot login after trying everything....

Getting started with a UNIX computer system

Intro to UNIX:

Students: listen to the TA who will show you material.
If you are still confused, you can read this material at your convenience: Interacting with a computer (in general) -- this webpage will explain the following topics:
TA: read the material before hand.
TA: Show students how to:

This webpage explain the most commonly used commands to list, navigate, create and remove UNIX directories: Working with files and directories using UNIX commands

TA: read the material before hand.

TA: Show students how to use:

pwd command
cd command
(Show how to use cd with an absolute path first, and then with a relative path)
Special directories: / ~ . and, ..
(Use ls commands to list content of the current directory after each cd command)
mkdir command
rmdir command
mv command
- used to rename a file or directory
- used to move a file/directory from one directory to another
(Use ls commands to list content of the affected directories after each mv command)

TA: issue all these commands and show students the results. Explain what the command does and execute the command. Read the webpage Working with files and directories using UNIX commands for ideas on what examples to use.

Script of the TA:

Do point 1 above
After explaining the ls command, let student practice the command with the first applet below.
Do point 2 above (partially)
After explaining the cd command, let student practice the command with the second applet below.
After the applet exercise, finish the other commands given in point 2
Afterwards, have students open a terminal and do examples (see below) with a real computer.
Finally, conclude the lab by having students send an email

Exercise for students

ls Exercise: type in the command in the Command input field that accomplishes the given task

Error loading Java applet

Tasks:

current directory

/home/bob

List the content of the current directory
List the content of bob's "photos" directory using a absolute path
List the content of bob's "photos" directory using a relative path
List the content of sally's home directory using a absolute path
List the content of sally's home directory using a relative path

cd Exercise: type in the command in the Command input field that accomplishes the given task

Error loading Java applet

Tasks:

current directory

/home/bob

Starting in bob's home directory, use a absolute path to change the current directory to sally's home directory
Now list the content of the current directory
From sally's home directory, use a relative path to change the current directory to bob's home directory
Now list the content of the current directory
From bob's home directory, use a relative path to change the current directory to sally's "music" directory
Now list the content of the current directory
From sally's "music" directory, use a relative path to change the current directory to bob's "photos" directory
Now list the content of the current directory

Students should learn to launch all of these three applications (ask the TA for help if necessary):

a terminal,
firefox, and
a file browser.

(For the file browser, they may need to double-click the desktop "Documents" icon, and then click "Up" to see their home directory.)

Using the file browser, you can visually traverse the tree structure of the file system (please read Cheung's notes for details).

Students should try out these commands by themselves inside a terminal: (anything after with '#' is a comment, and does not need to be typed):

pwd # print working (current) directory # Notice the output: /home/yourid ls # list # Notice the output ls -l # list, long format # Notice the output ls / # list the root director # Notice the output
cd cs170 # change current directory (it should exist) # Should be empty.... pwd # Notice the output: /home/yourid/cs170 ls
mkdir lab1 # create a subdirectory ls
cd lab1 pwd ls # Should be empty touch myfile # create an empty data file ls # Can you see the file name ?
cd # Can you guess which is the current directory ? pwd # Did you guess correctly ?
cd /home/cs170002/share ls touch myfile # this should fail for students ls /home # /home contents depend on machine

TODO

Whether you finish the exercise or not, in the last ten minutes students should must send us an email (because it is a useful skill for getting help later).

How to send emails:

Using firefox, students should login to some webmail service (e.g. mail.yahoo.com or gmail.com).

Learnlink is available at https://www.learnlink.emory.edu/login/, but you can use gmail, hotmail, yahoo, whatever.

Note on using learnlink to send email:

To compose a message in learning, use "New Message" under "Create".
It is not enough to enter the "To" address in its box, you must also click the "Add" button next to the box.

This is what I want in the email:

To: cs170002@mathcs.emory.edu Subject: lab1

In the body of the email, copy-and-paste the terminal window contents (the result of whatever commands, mistakes OK).

Note:

Do not use the email address: "cs170002@emory.edu" ******* The emory.edu domain does not work **********

How to copy-and-paste in UNIX:

To copy from the terminal, you first select the text with the left mouse button
(it scrolls, so you can select more than just the visible text).
Copy the selected text with Control-Shift-E
(or the Edit menu, or the "Copy" button),
Now paste the copied text into the webmail message (with Control-V, or the "Paste" key).

Some logistics:

Students are welcome to finish early (they can leave after turning in the lab). If you stick around, you are welcome explore the desktop and the share directory. Maybe try the editor (gedit), and so on.
Students may prefer the "bash" shell over the default "ksh"", because it lets you edit and recall commands using the arrow keys.
To start bash, enter the command "bash".
You can also change your default shell to bash at this website (it takes effect at your next login): https://enid.emory.edu/myaccount

A handout of UNIX commands
- Here is a small handout (summary) of UNIX command that you can print for reference: click here