computer literacy - soict · 2020. 12. 3. · computer literacy 1 3 linux provides: – user...

Lecturers: Dr. Nguyễn Đức Toàn Dr. Đặng Tuấn Linh Assoc.Prof. Trương Thị Diệu Linh Department of Data and Computer Network, School of Information and Communication Technology

Computer Literacy

Outline 22

�  3 parts ¡  Introduction to Linux ¡  Introduction to LaTeX ¡  Introduction to Beamer

� At least 1 test on Linux (30%), + Beamer (20%) + 1 final on Latex (50%)

� Website of the course: �  users.soict.hust.edu.vn/linhtd �  Looking for “Computer Literacy”

Introduction to LINUX

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� Open source software (OSS) � Operating System � Linux Operating System � Basic commands � Getting help � Exercises

Open Source Software

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� Activities on a software ¡  Creating, distributing, using, modifying ¡  Compiling: from source code to binary executable code ¡  Reverse Engineering: from binary code to source code ¡  Managing: change rights on others actions

�  Commercial software ¡  Only the right to use is allowed (with charge)

� Open source software ¡  Only the right to manage is not allowed

Popular opensource software

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�  Firefox �  Linux � OpenOffice � Gimp � Apache � MySql/PostgreeSQL � ….. � How do we know which SW is OSS ?

Software License

Software license defines what a user can do with a SW. •  Commercial SW license

•  User pays to get the license for a single user

•  License forbids users from modifying, re-distributing the SW

•  Open source SW •  License allows users to use, modify and re-distribute the SW

•  SW is usually re-distributed free of charge.

•  Copy-left license: Re-distribution of modified or non-modified SW must retain the original license à derived work becomes OSS.

•  Example of OSS license: GNU GPL, Apache license, BSD License...

Open Source vs Commercial Software

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Developed by users Developed by software owner (professionals)

No explicite investment cost Explicite Investment cost (normally hight)

Complex support Limit by many rules

No limit creation Limit by many rules

Public algorithms and mechanisms

Hidden mechanisms/algorithms

Risk to be discontinued

Risk to be closed

Supp

What is an Operating System?

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� Operating System ¡  Software that

÷ manages (allocates and de-allocates) system resources in an efficient and secure manner

÷  System resources include: ÷  CPU ÷  Memory: RAM ÷  Storage: Hard disk ÷  Peripheral devices: Printer, Keyboard, Monitor, Mouse ... ÷  Network communication.

÷  Provides interfaces for users to use system resources ÷  Desktop Environment ÷  Shell command line.

The roles of operating system

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System Resources

Hardware Software

System Software

Application Software

OBSOLETE TYPES OF OPERATING SYSTEMS

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�  Single-user, single-process operating systems: ¡  allow only one user at a time on the computer system ¡  user can execute/run only one process at a time

Examples: DOS, Windows 3.1

�  Single-user, multi-process operating systems: ¡  allow a single user to use the computer system ¡  user can run multiple processes at the same time

Example: OS/2

CURRENT OPERATING SYSTEMS

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� Multi-user, multi-process operating systems: ¡  allow multiple users to use the computer system

simultaneously ¡  Each user can run multiple processes at the same time

Examples: UNIX, LINUX, MacOS, Windows (2000, XP, Vista. Windows 7, 8, 10)

Under Linux: By logging on system under different terminals running programs

Under Windows: switching user

LINUX Operating System

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12 � LINUX is a

multi-user, multi-process operating system � LINUX is designed to facilitate programming, text

processing and communication – Network communication is well integrated in

Linux such as it is rather transparent to users – Files in a LAN can be shared so that it is seen

from any host as local files.

USES OF LINUX

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� Linux provides: – User Support Tools

•  Text processing (vi, sed, awk) •  Productivity applications

– Programmer Support Tools •  Programming languages & compilers (C, C++, Java) •  Shell scripts •  Personal software process: version control

–  Source Code Control System (SCCS) –  Revision Control System (RCS)

– Linux as server •  Web server, mail server, application server

WHERE TO GET LINUX

�  Install your own Linux system ¡  Separate machine ¡  Dual boot: co-existence with other OS ¡  Linux on a CD (slow) ¡  Virtual Machine (slow and hot)

� Other ¡  Cygwin: Unix utilities on Windows ¡  Windows Services For Unix (for some versions of Windows)

� Lab environment ¡  Redhat 9.0

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Computer Literacy

History of UNIX

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�  Invented by Ken Thompson at AT&T in 1969 � First version written in assembly language

¡  single user system, no network capability

� Thompson, Dennis Ritchie, Brian Kernighan l  rewrote Unix in C: processor/architecture independent

� Unix evolution: ¡  Bell Labs, USL, Novell, SCO ¡  BSD, FreeBSD, Mach, OS X ¡  AIX (IBM), Ultrix, Irix, Solaris (Sun), …

History of Linux

- GNU project is created by Rechard Stallman in 1982 with objective to create an UNIX-like operating system

-  GNU project lists all the GNU OS components: kernel, utilities, applications...

-  In 1990, components (except kernel) were developed independently and could run well on UNIX

-  Kernel were not received enough development investigation.

History of Linux

•  1991 Linus Torval wrote a Kernel independently with GNU Project

•  1992 GNU Project utilities, applications + Linux kernel are integrated together à GNU/Linux operating system

•  License under GNU GPL as an OSS

COMPONENTS OF LINUX

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User

Application (shells, compilers, utilities,…)

Programming libraries (open, close,read, write, ...)

OS kernel (managing file system, memory, peripheric)

Hardware

Interface

Linux Distributions

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� A distribution: � A combination of Linux components and released

to users. � Base distributions:

¡  Redhat ¡  Debian ¡  Suse ¡  …

� Derived distributions: ¡  Fedora ¡  Ubuntu ¡  …

� www.distrowatch.com

Linux Distribution

Start and stop Linux system

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� Start and login to the system using given user name and password

� Distinct the graphical and the textual user interfaces

� Shudown the system ¡  Using mouse ¡  Using command poweroff

Virtual consoles

•  Virtual console allows opening different working session on the same machine

•  Linux allows openning upto 8 virtual consoles, each console corresponds to one session

Ctrl+Alt-F1 : Virtual console 1 (text interface)

Ctrl+Alt-F2 : Virtual console 2 (text interface) ...

Ctrl+Alt-F7 : Virtual console 7 (graphical interface)

Linux Shell

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�  Shell is a traditional user interface of Linux �  = the “command line” Features of Shell:

¡  Interpret and execute commands ¡  Command history and editing ¡  Command scripting: simple program of shell command ¡  Job control: view job, kill running job ...

Linux Shells

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�  sh ¡  Bourne shell: Steve Bourne, 1978 ¡  Almquist shell (ash): BSD sh replacement ¡  Bourne-Again shell (bash): GNU/Linux

�  csh ¡  C shell, Bill Joy, BSD, 1978

�  tcsh ¡  Tenex C shell (tcsh): GNU/Linux

�  others: Korn shell (ksh), Zshell (zsh), …

Using shell

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� Starting shell (login) � Starting shell emulation (terminal) � Switching between shell (Alt-Fxx) � Getting information from the prompt � Structure of Shell command

$ command-name [options] [args] � Shell commands are case sensitive

Command Prompt

n  Shell executes iteratively the following tasks: ¨ Display command prompt, wait for user commands.

¨ Receive and Analyse the user command

¨ Execute the user command

[tuananh@hanoi home]$ <command of user> [root@hanoi home]# <command of root>

Host name Login name Working directory prompt

Example

login: tuananh

password: xxxxx

[tuananh@hanoi tuananh]$ echo hello↵

hello

[tuananh@hanoi tuananh]$ exit↵

Linux command structure command [-options] [arguments]

¨ command: command name

¨ options: some way to execute the command

¨ arguments : arguments of the command

¨ Each option is usually represented by a single character after (“-”)

¨ Options could be combined together after a single “–”.

Example -asli is equivalent to -a -s -l -i

¨ Options and arguments are separated by spaces.

¨ Commands are case sensitive

Some Basic Commands

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ls - list files less - show content of file logout - logout from system date - display date and time who - display who is on the system clear - clear terminal screen script - make record of a terminal session uname -a - print current OS detail (version etc.) man - find and display system manual pages

Getting Help: System Manual

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Section No. Description

1 User commands

2 System calls

3 C library functions

4 Special system files

5 File formats

6 Games

7 Miscellaneous features

8 System administration utilities

The man Command

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¢ show pages from system manual Syntax: man [options] [-S section] command-name % man date % man -k date % man crontab % man -S 5 crontab ¢ Caveats:

Some commands are aliases Some commands are part of shell

More help: online

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�  Some web sites

� Or find your own: ¡  Google command, arguments, error messages

Handons Exercises

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� Start and stop the system � Using shell � Basic command � Getting help by using “man”

Using basic command

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� Using command uname � Using command clear � who � whoami

Getting help

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� Using man command to get informations about command in the linux

Practical exercises

•  Use “man” for getting command description and syntax

–  login, logout –  mkdir, rm, cp

–  ls –  cd –  pwd –  clear –  who