CS 497C - Introduction to UNIX 
Lecture 1: Getting Started
Chin-Chih Chang chang@cs.twsu.edu

Objective and Preface
* This course is to learn the fundamentals of UNIX. This course introduces the 
  concept of UNIX operating system and the essential commands of UNIX . 
* UNIX was never designed for the world. There is a method to this madness.
* Many Internet applications are powered by UNIX.

The Operating System
* An operating system (sometimes abbreviated as "OS") is a program that 
  functions as  a virtual machine (layer of software on top of bare hardware) 
  and a resource manager (software that controls access to computer).
* It interacts with two agencies: applications and a command language 
  interpreter.
* DOS, Windows, Mac OS, and UNIX are examples of the operating system.

The UNIX Operating System
* UNIX (sometimes spelled "Unix") is an operating system that originated at 
  Bell Labs in 1969. Ken Thompson and Dennis Ritchie are considered the 
  inventors of UNIX.
* UNIX has evolved as a kind of large freeware product, with many extensions 
  and new ideas provided in a variety of versions of UNIX by different 
  companies, universities, and individuals.

Knowing Your Machine
* Unlike Windows, UNIX can be used by several users concurrently.
* You can access to such a multiuser system through a terminal or a 
  workstation.
* A terminal consists of a monitor and a keyboard.
* A workstation has its own CPU, memory, and hard disk.

Knowing Your Keyboard
* Every key on your computer has a function in UNIX. 
* Each character has its ASCII value.
* [Enter] / [Return] is used to terminate a line.
* [Backspace] corrects typing mistakes.
* [Ctrl] is used in combination with other keys to produce control characters.
* [Alt] combinations are used in emacs.

The System Administrator
* A system administrator is in charge of administration of the system.
* The system administrator is responsible for: 
 - the entire setup,
 - user accounts allocation,
 - file systems maintenance,
 - backups,
 - disk space management,
 - other assignments.
* The administrator has a special user account; it is called root.

Logging In and Out
* Logging In
login: remeo [Enter]
password:
Last login: Mon Aug 20 22:11:17 on tty2
$
* The shell produces the prompt and accepts all your input from the keyboard.
* Logging Out
$ [Ctrl-d]
$logout[Enter]
$exit[Enter]
login:

Trying Out Some Commands
* passwd: changing your own password
* who: who are the users?
* who am i
* tty: know your terminal name
* echo $SHELL: know your shell
* echo $TERM: know your terminal type
* set: know your envirnoment

Two Important Observations
* UNIX commands are in lowercase
* The [Enter] key
* When Things Go Wrong
* Backspacing doesn't work - [Ctrl-h], [Del]
* A command has to be interrupted - [Ctrl-d], [Ctrl-c] [Delete] 
* Killing a line - [Ctrl-u]

Other Problems
* Suspend a job - [Ctrl-z], resume a job - fg
* Stop scrolling - [Ctrl-s], resume scrolling - [Ctrl-q]
* Restore a terminal - stty sane
* [Enter] - [Ctrl-j] or [Ctrl-m]
* Close the program - q, quit, exit, or [Ctrl-d]

What's Next
* More commands
* How It All Clicked
* Linux and GNU
* Inside UNIX
* Read Chapter 1.