introduction to linux_dr mohamad sobh

8/2/2019 Introduction to Linux_Dr Mohamad Sobh

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Introduction to LinuxDr. M. Sobh


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Agenda

Overview Installation Linux GUI File System Administration Shell Shell Scripting Programming Advanced Linux Software


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Overview

Operating System Hardware Types Operating Systems Types Linux Types Ubuntu Operating System


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Operating System

Hardware dependent Software. Consisting of programs and data. Runs on computers.

Manages computer hardware resources. Provides common services for execution of various application software.


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Operating Systems Types

Microsoft Family DOS, Windows 3.1 / 95 / 98 / Me / 2000 / XP / Vista / 7 /

WinCE / NT Server / 2003 / 2008 MAC Family

MAC OS / MAC OS Server Unix

HP-UX, AIX, Solaris, MAC OS X Linux

Fedora, Red-Hat, Ubuntu, Centos...


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Linux Types

Ubuntu, CentOS Debian Fedora Suze Android and Google Chrome OS


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Ubuntu Operating System

By Canonical Ltd at 2004 Latest Version: 11.04 Supported Language: 55 Supported Hardware: Intel 32 and 64 and compatibles

License: Free Types: Client 32 and 64 / Server 32 and 64


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OS Market Share

Client Microsoft: 81% MAC: 11% Linux: 3%

Server Microsoft: 30% Linux: 70%

Mobile

Microsoft: 3% Linux: 28% Apple: 18% Symbian: 37% Blackberry: 14%

Mainframe andSupercomputers

Microsoft: 1% Unix and Linux: 98%

Industry Microsoft: 10% Linux: 50% Custom: 20% None: 20%

References www.eetimes.com www.linuxfordevices.com www.wikipedia.org


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Installation

Source Type Live CD Live USB

Installation Type

Standalone in a separate partition Virtual partition - for windows users

Requirements for Client Hard-disk space: 17 GB and 30 GB is recommended RAM: 1 GB and 2 GB is recommended

CD-Image Download http://www.ubuntu.com/download
http://www.ubuntu.com/download


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Linux GUI

System Menu Desktop Basic Software

Calculators

Text Editor Games and Graphics Internet Office Media Date and Time and Zone Chat Language System Start / Shutdown / Suspend


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File System

Basic File Browser Linux File System Structure Mounting Other Drives and External Drives File Permissions

Creating Folders and Files


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ShellCommand Line Interface to Manage Linux


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Listing Files and Directories

lsCourses.pdf linux.ppt Linux.ppt Qt.run

ls -l-rwx--x--x 1 sobh sobh 725286856 2011-06-11 15:30 Qt.run

ls -aCourses.pdf linux.ppt Linux.ppt Qt.run .System.dat

ls ~ --> list all files at user account root


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Making and Browsing Directories

mkdir ShellTestcd ShellTestmkdir folder1mkdir folder2cd folder1

pwd --> /home/useraccountname/ShellTest/folder1mkdir folder1amkdir folder1bcd .

pwd --> /home/useraccountname/ShellTest/folder1cd ..

pwd --> /home/useraccountname/ShellTestcd folder1/folder1a

pwd --> /home/useraccountname/ShellTest/folder1/folder1acd ~/ShellTest pwd --> /home/useraccountname/ShellTestls folder1 --> folder1a folder1bcd folder1ls . --> folder1a folder1bls .. --> --> folder1 folder2


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Making and Managing Files

cd ShellTest

cat > file1.txtWelcome to Linux ShellWelcome to Linux World^D

cat file1.txt -->Welcome to Linux ShellWelcome to Linux World

ls --> file1.txt folder1 folder2cp file1.txt file2.txtls --> file1.txt file2.txt folder1 folder2mv file1.txt myfile1.txtmv myfile1.txt folder1mv file2.txt folder2/myfile2.txt

cp folder1/myfile1.txt tempfile.txt

rm tempfile.txt


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More Managing Files and Folders

mkdir tempfolder mkdir tempfolder/tempsubfolder rmdir tempfolder --> failrmdir tempfolder/tempsubfolder rmdir tempfolder --> succeedmkdir tempfolder

mkdir tempfolder/tempsubfolder

mkdir tempfolder mkdir tempfolder/tempsubfolder cp -r tempfolder tempfolderbackuprm -r tempfolder mv tempfolderbackup tempfolder mkdir basefolder mv tempfolder basefolder


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Displaying the File Contentscat > file1.txt...long text...^Dcat >> file1.txt...additional text...^Dcat file1.txtclear --> clear shell screenless file1.txt --> view contents in pages, use [Space Bar] and [q]head file1.txt

man head --> command help, use [q] to quithead -1 file1.txt --> view firs 1 linehead -n 1 file1.txt --> view firs 1 linehead -c 10 file1.txt --> view first 10 letterstail -1 --> view last 1 linegrep Egypt file1.txt --> all lines with Egyptgrep -i egypt file1.txtgrep Egypt *grep -r Egypt *grep -c Egypt file1.txtgrep -v Egypt file1.txt --> all lines without Egyptwc -w file1.txtwc -l file1.txt


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Redirection

cat > file.txtcat >> file.txtcat file.txtcat file.txt file.txtcat file.txt > bigfile.txt

cat bigfile.txtcat file.txt file.txt > bigfile.txtcat bigfile.txtcat file.txt file.txt >> bigfile.txtcat bigfile.txtls > files.txt

grep Egypt file.txt > result.txt

whowho > temp.txt --> list of logged in users

sort < file.txtsort < file.txt > sorted.txt


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Wildcards

lsls *ls *.txtls f*.txtls f*.*ls file?.txt

ls [fc]*.txt


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Getting Help

man cp --> command helpaprops copy --> matched command


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File System Securitycat > myfile

mkdir myfolder ls -l-rw-r--r-- 1 sobh sobh 92 2011-07-19 05:38 myfiledrwxr-xr-x 4 sobh sobh 4096 2011-07-19 05:38 myfolder

permissions (folder)(owner/group/others)

chmod u+x myfilechmod go+w myfile-rwxrw-rw- 1 sobh sobh 92 2011-07-19 05:38 myfilechmod u-x myfilechmod go-w myfile-rw-r--r-- 1 sobh sobh 92 2011-07-19 05:38 myfile

sudo bash --> switch to root privilegeschown root:root myfile-rw-r--r-- 1 root root 6 2011-07-19 06:03 myfileclose and reopen the shellcat myfile --> can viewcat > myfile --> cannot appendsudo bashchown sobh:sobh myfileclose and reopen the shell

cat > myfile --> can append


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Processes and Jobs

ps --> list active processessleep 10lunch sleep process for 10 sec then go back after finish

sleep 10& -->[1] 16717 ([Job Number] Process ID)lunch sleep process for 10 sec in background then goback immediately

sleep 10& -->[2] 16718

sleep 100^Z --> suspend the process

bg --> list background processes

sleep 100sleep 100

jobs --> list all jobs with numbers[1]- Running sleep 100 &[2]+ Running sleep 100 &fg 1


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Processes and Jobs

sleep 100&sleep 100&

jobs[1]- Running sleep 100 &[2]+ Running sleep 100 &kill %2

jobs[1]- Running sleep 100 & ps16756 pts/0 00:00:00 sleepkill 16756

sleep 100^z[1]+ Stopped sleep 100

ps16764 pts/0 00:00:00 sleepkill 16764 --> failedkill -9 16764 --> killed


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Other Commands

1.cat > file.txt..very long content .. ^dcompress file.txt --> produce compressed file file.txt.Zuncompress file.txt.Z --> uncompress the filegzip file.txt --> produce compressed file file.txt.gz

gunzip file.txt.gz --> uncompress the file

2.tar -zcvf myfolder.tar.gz myfolder tar -zxvf myfolder.tar.gz

3.if tar is not installedsudo bash --> to login as rootapt-get install tar --> to download and install tar

4.sudo bash --> to login as root

synaptic --> lunch Ubuntu advanced package installer


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Other Commands

1.echo Hello Worldecho Hello World > file.txtecho Hello World | wc -w

2.

historyhistory 10 --> last 10 command

3.gedit --> lunch visual text editor

4.echo $PATHPATH=$PATH:~/ShellTestecho $PATH


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Text Editing Using VI


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Text Editing Using VI

vi vi: start empty file vi vi filename: start vi and open filename i: insert mode

ESC: command mode yy: copy current line p: past to the next line w filename: save to the filename w: save to the existing file q: quit q!: quit any way wq: save and quit o filename: open a file


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Why?

VI is very important to edit and view files at remote terminals


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Shell Scripting


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Simple Shell Scripting

Save following script in a file [testshell]----------#!/bin/shmkdir folder1mkdir folder1/folder1amkdir folder1/folder1b

mkdir folder2

echo hello world > file1.txtcp file1.txt folder1mv file1.txt folder2

echo done.----------chmod u+x testshell./testshell --> the file is executedaltPATH=$PATH:.testshell


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Advanced Shell ScriptingEdit [testshell] with following script

----------#!/bin/sh# This file looks through all the files in the current# directory for the string Egypt, and then prints the names of # those files to the standard output.for file in *do

if grep -q Egypt $filethenecho $filefidoneexit 0----------


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Advanced Shell Scripting

Shell Scripting Supports: Variables and Constants Loops Conditions

Functions


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Compiling C/C++ Programs


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Compiling Simple C Program

Save following code in hello.c file:------------------#include "stdio.h"int main(int argc, char* argv[]){int height;

printf("Enter your height (cm):");

scanf("%d", &height); printf("Your ideal weight %d kg\n", height-100);return 0;}------------------gcc hello.c --> produce executable file a.outa.out

gcc hello.c -o hello --> produce executable file hellohello-------------------gcc and cc are both c compilers (identical in Ubuntu)


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Compiling Simple C++ Program

Save following code in hello.c file:------------------#include

using namespace std;

int main(int argc, char *argv[])

{int height;coutheight;cout


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Compiling Multi-File ProgramsWrite files:weight.h----------

int weight(int height);weight.c----------int weight(int height){return height - 100;}main.c----------#include "stdio.h"#include "weight.h"

int main(int argc, char* argv[]){int height;

printf("Enter your height (cm):");scanf("%d", &height);

printf("Your ideal weight is %d kg\n", weight(height));return 0;}-----------------gcc main.c weight.c -o idealweight --> Compile and Link or gcc -c main.c --> Compile Only main.c and produce main.ogcc -c weight.c --> Compile Only weight.c and produce weight.o

gcc -o idealweight main.o weight.o --> link main.o weight.o to idealweight


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Using External LibrariesWrite files:trig.c----------

#include #include #include

int main(int argc, char *argv[]){char input[25];double angle;

printf("Enter the angle in radians :");if (!fgets(input, 25, stdin))perror("error!!.\n");angle = atof(input);

printf("sin(%0.3lf) = %0.3lf\n", angle, sin(angle)); printf("cos(%0.3lf) = %0.3lf\n", angle, cos(angle)); printf("tan(%0.3lf) = %0.3lf\n", angle, tan(angle));return 0;}-----------------gcc trig.c -o trig --> gives link errors (math library not provided)gcc trig.c -lm -o trig --> use a library with name libm


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Compiling a Shared Libraryusing files weight.c weight.h main.c

gcc -fPIC -c weight.c --> Compile Only weight.c and produce weight.ogcc weight.o -shared -o libweight.so -->produce a shared library libweight.so

gcc -c main.c --> Compile Only main.c and produce main.o

gcc -lweight -L. main.o -o idealweight --> link and produce the executable

cp libweight.so /usr/lib --> copy the library to common place for current user or cp libweight.so /lib --> if you are a root user

idealweight --> execute the application

to test which library is required by an executable

ldd idealweightldd trig


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Compiler Optionsusing files weight.c weight.h main.c

gcc -g -Wall main.c weight.c -o idealweight

-Wall turn on all warning options-g allow future debugging


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Debuggingusing files weight.c weight.h main.c and compile with

gcc -g -Wall main.c weight.c -o idealweight

gdb idealweight

(gdb)list main.c:1(gdb)list weight.c:1(gdb)list main(gdb)list weight(gdb)run(gdb)break weight(gdb)run(gdb)print height(gdb)next(gdb)next(gdb)next(gdb)c(gdb)break main.c:7(gdb)run(gdb)next(gdb)next(gdb)c


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Make File

introduction to linux_dr mohamad sobh

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