1 UNIX Software Tools

Mauro Jaskelioff

Introduction

Course consists of 2 lectures per week plus 2 lab sessions per week

Assessment will be via exam and coursework

My contact details: Mauro.JASKELIOFF@nottingham.edu.c

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UST Assessment

Activity % of Overall Mark

Coursework 1 - UNIX Tools

20%

Coursework 2 - UNIX Shell Scripting

20%

Exam: 1.5 hours 60%In addition to this, you will be expected to attend weekly laboratory sessions

Important Information

Lecture notes will be available on the shared folder:

U:\2nd Year Share\Computer Science Courses\Semester Two\UST

Important Information (2)

Labs will start: Thursday 15th March, 10:15-11:15am,

SSB119 Friday 16th February, 10:15-11:15am,

SSB119

Coursework: 20th March → 10th April (to be confirmed) 17th April → 15th May (to be confirmed)

Important Information (3)

Exam New course, so no past papers. Model exam paper with sample

answers will be given

UST Reading List

On-line materialUNIX in a Nutshell, Arnold Robbins,

O’Reilly: might be used as a reference.But the main reference is:

System documentation.Any book on UNIX.I like “The UNIX Programming

Environment” by Kernighan and Pike, but it’s rather outdated (1984!)

Course Outline Introduction to UNIX Useful Commands File System Navigation Text Editing Environment Variables UNIX I/O: pipes and

redirections File processing: grep

and regular expressions

Sed and awk UNIX Bourne shell and

shell scripting Compilers, interpreters,

debuggers Documentation systems Software Engineering

Tools: build management systems and version control systems

An Introduction to UNIX

Mauro Jaskelioff(based on Gail Hopkins’s

slides)

Introducing UNIX

•What is UNIX ?

•UNIX Kernel

•UNIX Shell

•Example Commands

•UNIX Filestore - next lecture

What is UNIX?

UNIX is an operating systemAn operating system is the program

that controls all the resources of a computer system - both the hardware and the software

Most importantly, it allows you to make use of the facilities provided by the system. Every computer has an operating system.

Different Flavours of UNIX

Commercial: Sun Solaris, SCO, IRIXOpen source: Linux, FreeBSD, NetBSD

Lots distributions

Cygwin Not a full OS but an implementation of all

the standard tools and system calls of UNIX

MacOS X Underlying operating system is BSD

Parts of the UNIX System

Tools & Apps

Shell or GUI

Kernel

Hardware

UNIX KernelAt the core of each UNIX system (and

most operating systems)Loaded in whenever the system is

started upManages the entire resources of the

system, presenting them to you and every other user as a coherent system

You do not need to know about it in order to use a UNIX system, but very important if you are administering one.

UNIX Kernel (2)

Amongst the functions performed by the kernel are: managing the machine's memory and

allocating it to each process. scheduling the work done by the CPU so

that the work of each user is carried out as efficiently as possible.

organising the transfer of data from one part of the machine to another.

enforcing the access permissions that are set on the file system

UNIX ShellThe UNIX command line interface

is called the ‘shell’The shell is a program interpreterThere are many different shells,

for example csh, bash, sh. Usually you will run only one type

of shell in a login session

What is a Command Line Interface?

In Windows you usually do things by selecting something with the mouse and then clicking (GUI), but there is limited command line support

In UNIX, traditionally, you do things by typing in commands, but GUIs are common nowadays.

Command Line Completion

Very useful although not always available (available in bash!)

Start typing command (or file name) and then press tab

The shell will try to automatically finish the word for you If more than one choice, press tab again

and the shell will list the possibilities

Copying and Pasting

In Windows you cut and paste using items in the Edit menu

In UNIX you can also use your mouse Left button (click and drag) to

highlight the text you want to copy Middle button (click) to paste the text

somewhere else

A Shell Window

Accessing your Linux account

Use NoMachine

For more info, read document by Paul Dempster (see U drive)

It’s a client-server system, with a twist

X-Windows In a normal client-server system (for example,

an email system) the software on the local host is the client and the software on the remote host is the server.

In a X-Windows system this is reversed. The X-Windows server is on your local

machine. It provides the following services: keyboard input, mouse, procedures for drawing on the screen, etc.

The clients are on the remote host. Client processes running on the remote machine use your X Server to get the input from your keyboard and mouse and to display their output on your screen.

Opening and closing the terminal

To open

the terminal:

You can close it by typing exit or pressing ^D (Ctrl+D)

Shell vs. GUIAdvantages of command line interfaces vs

graphical interfaces: Easy to automate History of commands More productive (once you know what you are

doing) Works well over slow network connections

Disadvantages: More difficult at first (but you get used to it)

Linux at Home

The University’s Linux server is only accessible from within the campus

You might want to try installing Linux on your own PC, but this might not be trivial

A simpler option is to download a “live” distribution (a bootable CD)

UNIX CommandsShells perform user requests and they do this

by accepting commandsDifferent types of shell have different

commands, although the core commands are common

A command consists of one or more words separated by white space

The first word is the command nameSubsequent words (flags and arguments)

give additional information or modify the command

E.g. ls –l /usr

Command EntryA command is only entered when you

press the ENTER (or RETURN) keySpecial key strokes include:

DELETE or back space to delete the last character (also ^H)

^D to delete the next character ^W to delete the last word Alt+U to delete the entire line ^C to kill most commands ^A and ^E to go to the beginning or

end of the line

(^X means press the Control key and X at the same time)

Example UNIX Commands

whodatefingerpasswd

Example UNIX commands (2) The who command displays a list of current users

on the system Information includes usernames, where they are

logged in from and when they logged on

zlizmj pts/7 Mar 5 10:49

zuczpd pts/8 Mar 5 11:20

zlizmj pts/9 Mar 5 11:20

zliybzd pts/10 Jan 2 09:03

zliybzh4 pts/12 Jan 8 12:32

zliychj2 pts/13 Jan 7 13:50

zliyblj5 pts/19 Jan 26 15:46

zlizjc pts/22 Jan 3 14:45 (unix:1031.0)

zuczpd pts/15 Jan 3 12:06 (mb-gx520-030.nottingham.edu.cn)

Example UNIX commands (3) The date command displays the current date and

time:

Mon Oct 9 11:27:07 BST 2000

finger describes the person behind a username, for example,

finger gmh@marian gives:

Login name: gmh In real life: Graham M Hutton

Directory: /staff/gmh Shell: /bin/csh

Last login Thu Sep 16, 1999 on pts/2 from marian

No unread mail

Plan:

Example UNIX Commands -Changing your password

The passwd command changes your password

This is one of the first things that you should do

You are prompted for the old and new passwords (the new one twice)

You cannot change your password from the CS Linux server (passwords are stored on a Windows server)

Other Useful UNIX Commands

man - manual pagesinfo - more extensive documentationgpdf - viewer for PDF filesggv - viewer for postscript fileskonqueror - web browser and shared

folders browserbzip2 - compress a file (reverse bunzip2)

Summary

Introduction to UNIX

UNIX Kernel

UNIX Shell

Basic UNIX commands

Next Lecture: UNIX Filestore