Foils Prepared by Henry Helou

1
Foils Prepared by Henry Helou

• PHOBOS
• Computer account used for creating, modifying,
  compiling and executing programs - AIX UNIX
• (IBM RS6000 - See OPS124 Notes for details)
• COLUMBUS
• Used to store and maintain WebPages for FCE
  students.

2
Introduction to UNIX

• UNIX is the most popular operating system. Most
  large computers use UNIX as their operating
  system
• UNIX is a TEXT BASED system.

3
What is an Operating System

• Control program for a computer
• OS handles - communications between the
  application software and the computer hardware.
• Memory protection - system accounting
• smooth operation ? - Response Time

4

5
Bit of UNIX History

• MULTICS first interactive multi-user OS developed
  by Bell labs.
• Ken Thompson 1969 at ATT Bell Laboratories. -
  UNIX
• UNIX a pun on MULTICS not an acronym
• Given almost for free to Universities and
  Colleges to obtain a following into the business
  world.

6
Bit of UNIX History

• Generic version follows System V Release 4, with
  companies as Sun (Solaris), Hewlett Packard(HP)
  and IBM altering it to suit their customer base.
• Linux - LinusTorvalds

7
Overview of UNIX File Structure
8
Directories

• The directory of a disk is an area where the
  names and locations of files are stored.
• Each storage device such as a hard disk has at
  least one directory which is called Root.
• Directories make it more efficient to store files
  under logical categories or locations.

9
Directories

• Inverted Tree Diagrams visualize directory
  structures

Root ( / )
Students is theparent directory of hhelou
tmp
students
hhelou
10
Making Directories

• Building directories is similar in approach to
  building a house
• Begins from a foundation (root)
• Need to build in proper order (add on addition to
  house in right location)
• Need to step-back and look at construction

11
Overview UNIX Shell

• Pg. 11 of the Sobell text
• shell is the interface between the operating
  system and the user.- interprets instructions
• calls the program you want
• can also program the shell - script writing.

12
Limitations of UNIX ?

• Called terse, unfriendly difficult to learn.
• No news is good news. Gives more flexibility to
  programmer - confirmation of activity being
  completed is not given. Result more powerful -
  can string a succession of instructions together
  and they will be performed.

13
Basic Unix Commands

• Case sensitive
• Flags
• A flag is a letter or letters added to a command
  to indicate
• an option (see next slide for example)
• Flags are what make UNIX so powerful

14
MAN

• MAN is the online manual. Once you can log in,
  MAN will help you do everything else
• man ls (will provide details on how the ls
  command works, its options and how to call them.
• The -k flag means keyword (allowing you to obtain
  on commands that match the keyword).
• man password
• man -k password

15
List Files

• ls Displays compact list of files (excluding
• hidden files - beginning with period)
• ls -a Displays all files (including hidden
  files)
• ls -l Displays detailed list of files (excluding
• hidden files)
• ls -al Displays all files in detail form
  (including
• hidden files)

16
Additional Unix Commands

• Interrupt
• Stop output
• Resume output
• logout
• Delete character / word / line

• Ctrl C (c)
• Ctrl S
• Ctrl Q
• Ctrl D
• Ctrl H, W, U

17
Additional Unix Commands

• Pwd
• cd /tmp
• cd

• Displays current directory
• Changes to tmp directory
• Changes to home directory

18
Additional Unix Commands

• Find commands to
• delete a file
• change the permissions of a file
• Create a folder
• Find out who is logged in
• show processes running
• display a file on the screen

19
Changing Directories

• cd directory
• cd directory path
• cd
• cd .. (change to parent directory)

20
How to Logon to PHOBOS Server

• Run Telnet Program
• Type in your Login I.D.
• Type in your password

NOTE UNIX is case sensitive. Upper and Lower
case letters are recognized as different by UNIX.
21
What is the Telnet Application?

• Unix systems such as PHOBOS were originally
  designed to accommodate dumb terminals which
  were simply monitors and keyboards directly
  connected up to network
• Telnet allows the server to think that the
  users personal computer is a dumb terminal
• A common type of dumb terminal was Digital
  Equipment corporations VT100.

22
Telnet Application

• To launch or run the Telnet application from
  the Seneca computing lab, point and click onto
  the application terminal on the Windows 95
  desktop
• You can obtain a free version of Telnet
  application for home use from the internet
  (assuming you have computer system with modem).

23
(No Transcript)
24
(No Transcript)
25
(No Transcript)
26
Protecting your Computer Accounts

• It is important to assign an appropriate password
  to prevent unauthorized access to your computer
  accounts.
• Concerns regarding unauthorized use
• Illegal Activity
• Suspension of account
• Loss of data / Copying of assignments

27
Changing your Password

• After logging onto PHOBOS, you can change your
  password by typing at the prompt
• passwd ltENTERgt
• Note It is recommended to change password
  periodically.

28
Password Tips

• Combine upper and lower case letters
• Include a non alpha-numeric characters such as .
  - in your password
• Acceptable passwords on PHOBOS range from 6 to 8
  characters

29
Password Tips

• Avoid easily detected passwords such as
• names
• birth dates
• addresses
• patterns
• year and month

30
Password tips

• Use phrases and take the first letter of each
  word For example
• Autumn leaves Turn red, yellow, orange ALTRYO
• Add numbers and characters to words
• R1o2N3!

31
For Review - Basic Unix Commands

• Listing Files
• ls Displays compact list of files (excluding
• hidden files - beginning with period)
• ls -a Displays all files (including hidden
  files)
• ls -l Displays detailed list of files (excluding
• hidden files)
• ls -al Displays all files in detail form
  (including
• hidden files)

32
Additional Unix Commands

• Commands
• pwd Displays current directory
• cd /tmp Changes to tmp directory
• cd Changes to default directory
• man Online manual