CS 497C – Introduction to UNIX Lecture 1: Getting Started

1. CS 497C – Introduction to UNIXLecture 1: Getting Started Chin-Chih Changchang@cs.twsu.edu

2. 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.

3. 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.

4. 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.

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

6. 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.

7. 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.

8. 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:

9. 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

10. Two Important Observations • UNIX commands are in lowercase • The [Enter] key

11. 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]

12. What’s Next • More commands • How It All Clicked • Linux and GNU • Inside UNIX • Read Chapter 1.