This document provides an overview of experiments to be conducted in an Operating Systems lab. It includes:
1. 11 experiments covering Linux commands, vi editor, CPU scheduling algorithms (FCFS, SJF, Priority, Round Robin), the Banker's deadlock avoidance algorithm, page replacement algorithms (FIFO, LRU), and disk scheduling algorithms (FCFS, SSTF).
2. Hardware and software requirements for the lab including a 700MHz processor, 512MB RAM, 5GB hard drive space, VGA display, CD/DVD drive, and Ubuntu/Windows OS with Turbo C++ compiler.
3. The objectives of the lab are to familiarize students with operating systems,
Linux can be downloaded for free and was created to be an open source version of UNIX; it discusses how to install Linux by booting from a CD-ROM or making installation floppies, and then explains how to configure aspects of Linux like software installation and permissions. The document also provides an overview of common Linux commands for navigating and managing the file system, copying/moving files, and uninstalling a Linux operating system by removing it from the boot loader menu.
Linux can be downloaded for free from the internet with no registration fees or costs. It was created by Linus Torvalds as a freely available version of UNIX. Installing Linux involves checking hardware compatibility, repartitioning disks if needed, and booting from an installation CD or floppy disks. Basic installation kits include README files, boot disk images, and packages for common software. Configuring Linux allows customizing settings like installing additional software repositories. Common Linux commands allow navigating and managing the file system and permissions. Uninstalling Linux mainly involves removing it from the boot loader menu rather than deleting its files.
Linux is an open-source operating system used widely for servers and can also be installed on desktops and embedded devices. It uses a modular kernel called Linux and source code is freely available under licenses like GPL. Common Linux distributions include Red Hat, Debian, Ubuntu and others. The Apache web server is widely used open-source software that helped popularize the World Wide Web and can be configured using directives in configuration files.
This document provides a cheat sheet of common Linux commands and their usage. It covers basic file operations like copying, moving, deleting files and directories. It also includes commands for viewing files, compressing/decompressing files, finding files, remote access, and getting system information. The commands are explained over 3 pages with examples of proper syntax and usage for each one.
The e-book covers some of the really cool ways on how to go about using Linux from Terminal making your daily work much more efficient, less time consuming and of course geeky.
The structure of Linux - Introduction to Linux for bioinformaticsBITS
This 3th slide deck of the training 'Introduction to linux for bioinformatics' gives a broad overview of the file system structure of linux. We very gently introducte the command line in this presentation.
This document provides instructions on installing Linux, including collecting hardware information beforehand, preparing disk partitions, booting from CD-ROM, continuing the installation process by preparing filesystems and installing packages, and basic parts of an installation kit like README files, boot disk images, and the installation CD-ROM. It also covers uninstalling or removing software packages using either the graphical Synaptic tool or command line apt-get commands. Basic Linux commands like mkdir, cd, pwd, rmdir, chown, chmod, ls, and cp are described.
The document provides instructions on installing Linux, including collecting hardware information before installing, preparing disk partitions, installing from a CD-ROM, and basic package management tools for installing, upgrading, and removing software.
Linux can be downloaded for free and was created to be an open source version of UNIX; it discusses how to install Linux by booting from a CD-ROM or making installation floppies, and then explains how to configure aspects of Linux like software installation and permissions. The document also provides an overview of common Linux commands for navigating and managing the file system, copying/moving files, and uninstalling a Linux operating system by removing it from the boot loader menu.
Linux can be downloaded for free from the internet with no registration fees or costs. It was created by Linus Torvalds as a freely available version of UNIX. Installing Linux involves checking hardware compatibility, repartitioning disks if needed, and booting from an installation CD or floppy disks. Basic installation kits include README files, boot disk images, and packages for common software. Configuring Linux allows customizing settings like installing additional software repositories. Common Linux commands allow navigating and managing the file system and permissions. Uninstalling Linux mainly involves removing it from the boot loader menu rather than deleting its files.
Linux is an open-source operating system used widely for servers and can also be installed on desktops and embedded devices. It uses a modular kernel called Linux and source code is freely available under licenses like GPL. Common Linux distributions include Red Hat, Debian, Ubuntu and others. The Apache web server is widely used open-source software that helped popularize the World Wide Web and can be configured using directives in configuration files.
This document provides a cheat sheet of common Linux commands and their usage. It covers basic file operations like copying, moving, deleting files and directories. It also includes commands for viewing files, compressing/decompressing files, finding files, remote access, and getting system information. The commands are explained over 3 pages with examples of proper syntax and usage for each one.
The e-book covers some of the really cool ways on how to go about using Linux from Terminal making your daily work much more efficient, less time consuming and of course geeky.
The structure of Linux - Introduction to Linux for bioinformaticsBITS
This 3th slide deck of the training 'Introduction to linux for bioinformatics' gives a broad overview of the file system structure of linux. We very gently introducte the command line in this presentation.
This document provides instructions on installing Linux, including collecting hardware information beforehand, preparing disk partitions, booting from CD-ROM, continuing the installation process by preparing filesystems and installing packages, and basic parts of an installation kit like README files, boot disk images, and the installation CD-ROM. It also covers uninstalling or removing software packages using either the graphical Synaptic tool or command line apt-get commands. Basic Linux commands like mkdir, cd, pwd, rmdir, chown, chmod, ls, and cp are described.
The document provides instructions on installing Linux, including collecting hardware information before installing, preparing disk partitions, installing from a CD-ROM, and basic package management tools for installing, upgrading, and removing software.
The document provides an overview of the Linux filesystem, including its hierarchical tree structure with common subdirectories like /bin, /home, and /usr. It discusses useful commands for navigating the filesystem like cd, pwd, and running privileged commands with sudo. The document also compares the Linux and Windows filesystem structures and file types. It introduces package management with apt-get and the power of pipes in Linux.
The document provides instructions for various UNIX commands. It begins by listing commands for working with files like ls, more, emacs, mv, cp, rm, diff, and chmod. It also covers file compression with gzip and gunzip, printing files with lpr, and working with directories using mkdir, cd, and pwd. Additional commands covered find files using ff and grep, send messages with write, and email with elm. The document concludes with commands for managing processes like ps and kill, checking disk usage with du and quota, and viewing login history with last.
Linux is a widely used open-source operating system that can run on desktops, servers, and embedded devices. It includes basic commands like cal, date, cd, and cat. The document also provides overviews of installing and configuring the Apache web server, PHP, and MySQL to set up a basic LAMP stack on a Linux system.
Power point on linux commands,appache,php,mysql,html,css,web 2.0venkatakrishnan k
Linux is a widely used open-source operating system that can run on desktops, servers, and embedded devices. The document provides basic commands for Linux like cal to view a calendar, date to check the date and time, and cd to change directories. It also gives an overview of installing and configuring web servers like Apache and PHP as well as databases like MySQL on a Linux system.
This document provides an overview of shell scripting concepts including:
1) Shell scripting allows running lists of commands through a shell interpreter to perform tasks like file manipulation and text printing.
2) Popular shell types include bash, csh, ksh, and tcsh.
3) Benefits include reusability, availability on all systems, readability, and power through combining with tools like awk, grep and sed.
4) The document then covers bash scripting basics like variables, conditionals, loops, functions, arrays, dictionaries, and options to control shell behavior.
The document provides an overview of common Linux commands, including:
- cd to change directories
- ls to list directory contents
- mkdir to create directories
- pwd to print the working directory
- rm to remove files
- rmdir to remove directories
- cp to copy files
- find to locate files
- more and less to view file contents
- vi as a basic text editor
- ps to view running processes
- kill to terminate processes
CompTIA Linux+ Powered by LPI certifies foundational skills and knowledge of Linux. With Linux being the central operating system for much of the world’s IT infrastructure, Linux+ is an essential credential for individuals working in IT, especially those on the path of a Web and software development career. With CompTIA’s Linux+ Powered by LPI certification, you’ll acquire the fundamental skills and knowledge you need to successfully configure, manage and troubleshoot Linux systems. Recommended experience for this certification includes CompTIA A+, CompTIA Network+ and 12 months of Linux admin experience. No prerequisites required.
The document provides instructions on installing Linux including collecting hardware information beforehand, preparing disk partitions, installing from a CD-ROM, installing additional packages, and basic Linux commands. It also discusses uninstalling software using the synaptic graphical tool or apt-get command line tool and describes common Linux commands like mkdir, cd, ls, cp and their usage.
This document provides an overview and introduction to the hardware, software, and file structure of the EduBook device. It discusses the hardware components, how to open the case and access internal parts. It then summarizes the available operating systems, describes the Linux file structure and key directories. The document outlines software options like browsers and office applications that are preinstalled. It concludes with some tips on software issues, advanced options for running Windows programs in Wine, and contact information.
This document provides an outline for a lecture on basic UNIX commands. It covers commands for file management, printing, finding files, checking information about users, managing processes, connecting to other systems, and more. The lecture was prepared by Simonas Kareiva for students in the Department of Computer Science at Vilnius University.
This document provides a beginner's guide to learning Linux. It covers topics such as what Linux is, understanding files and folders, users and permissions, the root user, opening a terminal, basic commands like ls, cd, pwd, and tar for archiving files. The guide explains important Linux concepts and provides examples of common commands to get started using the Linux command line.
This document provides a beginner's guide to learning Linux. It covers topics such as what Linux is, understanding files and folders, users and permissions, the root user, opening a terminal, basic commands like ls, cd, pwd, and tar for archiving files. The guide explains important Linux concepts and provides examples of common commands to get started using the Linux command line.
This document provides a beginner's guide to learning Linux. It covers topics such as what Linux is, understanding files and folders, users and permissions, the root user, opening a terminal, basic commands like ls, cd, pwd, and tar for archiving files. The guide explains important Linux concepts and provides examples of common commands to get started using the Linux command line.
Linux is an operating system with several key components:
- A kernel that manages system resources and processes. Processes allow programs to run in memory simultaneously.
- Files and directories that organize data. Directories contain files and other directories.
- Tools like tar for backing up files and mounting disks. The mount command attaches filesystems.
- A shell interface for entering commands to interact with the system, along with utilities like ls, cp, and man.
- Permissions and variables that control access and store values for commands.
This document provides an introduction to the Linux operating system. It discusses that Linux is an open-source operating system based on Unix, and is commonly used over other operating systems due to its low cost, visible source code, and support for open-sourcing applications. The document then covers basic Linux commands for getting system information, navigating directories, manipulating files and getting command help. It also discusses techniques like autocompletion, command history, and wildcards to help users work more efficiently in the Linux terminal.
This document provides an overview of shell scripting. It begins with an agenda that covers introducing UNIX/Linux and shell, basic shell scripting structure, shell programming with variables, operators, and logic structures. It then gives examples of shell scripting applications in research computing and concludes with hands-on exercises. The document discusses the history and architecture of UNIX/Linux, commonly used shells like bash and csh, and why shell scripting is useful for tasks like preparing input files, job monitoring, and output processing. It also covers basic UNIX commands, commenting in scripts, and debugging strategies.
BITS: Introduction to Linux - Software installation the graphical and the co...BITS
This slide is part of the BITS training session: "Introduction to linux for life sciences."
See http://www.bits.vib.be/index.php?option=com_content&view=article&id=17203890%3Abioperl-additional-material&catid=84&Itemid=284
The document provides an overview of various operating systems including UNIX, Linux, and Windows. It discusses the history and development of UNIX including early projects at Bell Labs and Berkeley. It also summarizes key features of UNIX such as security, reliability, and multi-user support. The document then describes the UNIX directory structure and common commands like ls, cd, cat, and man.
Linux is a prominent example of free and open source software. It can be installed on a wide variety of devices from embedded systems to supercomputers. Linux is commonly used for servers, with estimates that it powers around 60% of web servers. Linux distributions package the Linux kernel with other software like utilities, libraries and desktop environments. Programming languages and build tools like GCC are supported. Embedded Linux is often used in devices due to its low cost and ease of modification.
The document provides an overview of the Linux filesystem, including its hierarchical tree structure with common subdirectories like /bin, /home, and /usr. It discusses useful commands for navigating the filesystem like cd, pwd, and running privileged commands with sudo. The document also compares the Linux and Windows filesystem structures and file types. It introduces package management with apt-get and the power of pipes in Linux.
The document provides instructions for various UNIX commands. It begins by listing commands for working with files like ls, more, emacs, mv, cp, rm, diff, and chmod. It also covers file compression with gzip and gunzip, printing files with lpr, and working with directories using mkdir, cd, and pwd. Additional commands covered find files using ff and grep, send messages with write, and email with elm. The document concludes with commands for managing processes like ps and kill, checking disk usage with du and quota, and viewing login history with last.
Linux is a widely used open-source operating system that can run on desktops, servers, and embedded devices. It includes basic commands like cal, date, cd, and cat. The document also provides overviews of installing and configuring the Apache web server, PHP, and MySQL to set up a basic LAMP stack on a Linux system.
Power point on linux commands,appache,php,mysql,html,css,web 2.0venkatakrishnan k
Linux is a widely used open-source operating system that can run on desktops, servers, and embedded devices. The document provides basic commands for Linux like cal to view a calendar, date to check the date and time, and cd to change directories. It also gives an overview of installing and configuring web servers like Apache and PHP as well as databases like MySQL on a Linux system.
This document provides an overview of shell scripting concepts including:
1) Shell scripting allows running lists of commands through a shell interpreter to perform tasks like file manipulation and text printing.
2) Popular shell types include bash, csh, ksh, and tcsh.
3) Benefits include reusability, availability on all systems, readability, and power through combining with tools like awk, grep and sed.
4) The document then covers bash scripting basics like variables, conditionals, loops, functions, arrays, dictionaries, and options to control shell behavior.
The document provides an overview of common Linux commands, including:
- cd to change directories
- ls to list directory contents
- mkdir to create directories
- pwd to print the working directory
- rm to remove files
- rmdir to remove directories
- cp to copy files
- find to locate files
- more and less to view file contents
- vi as a basic text editor
- ps to view running processes
- kill to terminate processes
CompTIA Linux+ Powered by LPI certifies foundational skills and knowledge of Linux. With Linux being the central operating system for much of the world’s IT infrastructure, Linux+ is an essential credential for individuals working in IT, especially those on the path of a Web and software development career. With CompTIA’s Linux+ Powered by LPI certification, you’ll acquire the fundamental skills and knowledge you need to successfully configure, manage and troubleshoot Linux systems. Recommended experience for this certification includes CompTIA A+, CompTIA Network+ and 12 months of Linux admin experience. No prerequisites required.
The document provides instructions on installing Linux including collecting hardware information beforehand, preparing disk partitions, installing from a CD-ROM, installing additional packages, and basic Linux commands. It also discusses uninstalling software using the synaptic graphical tool or apt-get command line tool and describes common Linux commands like mkdir, cd, ls, cp and their usage.
This document provides an overview and introduction to the hardware, software, and file structure of the EduBook device. It discusses the hardware components, how to open the case and access internal parts. It then summarizes the available operating systems, describes the Linux file structure and key directories. The document outlines software options like browsers and office applications that are preinstalled. It concludes with some tips on software issues, advanced options for running Windows programs in Wine, and contact information.
This document provides an outline for a lecture on basic UNIX commands. It covers commands for file management, printing, finding files, checking information about users, managing processes, connecting to other systems, and more. The lecture was prepared by Simonas Kareiva for students in the Department of Computer Science at Vilnius University.
This document provides a beginner's guide to learning Linux. It covers topics such as what Linux is, understanding files and folders, users and permissions, the root user, opening a terminal, basic commands like ls, cd, pwd, and tar for archiving files. The guide explains important Linux concepts and provides examples of common commands to get started using the Linux command line.
This document provides a beginner's guide to learning Linux. It covers topics such as what Linux is, understanding files and folders, users and permissions, the root user, opening a terminal, basic commands like ls, cd, pwd, and tar for archiving files. The guide explains important Linux concepts and provides examples of common commands to get started using the Linux command line.
This document provides a beginner's guide to learning Linux. It covers topics such as what Linux is, understanding files and folders, users and permissions, the root user, opening a terminal, basic commands like ls, cd, pwd, and tar for archiving files. The guide explains important Linux concepts and provides examples of common commands to get started using the Linux command line.
Linux is an operating system with several key components:
- A kernel that manages system resources and processes. Processes allow programs to run in memory simultaneously.
- Files and directories that organize data. Directories contain files and other directories.
- Tools like tar for backing up files and mounting disks. The mount command attaches filesystems.
- A shell interface for entering commands to interact with the system, along with utilities like ls, cp, and man.
- Permissions and variables that control access and store values for commands.
This document provides an introduction to the Linux operating system. It discusses that Linux is an open-source operating system based on Unix, and is commonly used over other operating systems due to its low cost, visible source code, and support for open-sourcing applications. The document then covers basic Linux commands for getting system information, navigating directories, manipulating files and getting command help. It also discusses techniques like autocompletion, command history, and wildcards to help users work more efficiently in the Linux terminal.
This document provides an overview of shell scripting. It begins with an agenda that covers introducing UNIX/Linux and shell, basic shell scripting structure, shell programming with variables, operators, and logic structures. It then gives examples of shell scripting applications in research computing and concludes with hands-on exercises. The document discusses the history and architecture of UNIX/Linux, commonly used shells like bash and csh, and why shell scripting is useful for tasks like preparing input files, job monitoring, and output processing. It also covers basic UNIX commands, commenting in scripts, and debugging strategies.
BITS: Introduction to Linux - Software installation the graphical and the co...BITS
This slide is part of the BITS training session: "Introduction to linux for life sciences."
See http://www.bits.vib.be/index.php?option=com_content&view=article&id=17203890%3Abioperl-additional-material&catid=84&Itemid=284
The document provides an overview of various operating systems including UNIX, Linux, and Windows. It discusses the history and development of UNIX including early projects at Bell Labs and Berkeley. It also summarizes key features of UNIX such as security, reliability, and multi-user support. The document then describes the UNIX directory structure and common commands like ls, cd, cat, and man.
Linux is a prominent example of free and open source software. It can be installed on a wide variety of devices from embedded systems to supercomputers. Linux is commonly used for servers, with estimates that it powers around 60% of web servers. Linux distributions package the Linux kernel with other software like utilities, libraries and desktop environments. Programming languages and build tools like GCC are supported. Embedded Linux is often used in devices due to its low cost and ease of modification.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
1. NCS-451/JP/ 1
Meerut Institute of Technology, Meerut
Department of Computer Science & Engineering
LAB MANUAL
Lab Name: Operating System
Lab Code: NCS-451
Jyotirmay Patel
2. NCS-451/JP/ 2
Operating System (ECS-551)
List of Experiment
S.No. Program Page No.
1. Testing the Linux /Unix Commands. 5
2. Getting familiar with vi editor and environment. 10
3. Write a C program to simulate FCFS CPU scheduling algorithm. 14
4. Write a C program to simulate SJF CPU scheduling algorithm. 20
5. Write a C program to simulate Priority CPU scheduling algorithm 27
6. Write a C program to simulate Round Robin CPU scheduling
algorithm.
33
7. Write a C program to simulate Banker’s algorithm for deadlock
avoidance.
40
8. Write a C program to simulate FIFO Page replacement algorithm. 50
9. Write a C program to simulate LRU Page replacement algorithm 55
10. Write a C program to simulate FCFS disk scheduling algorithm. 61
11. Write a C program to simulate SSTF disk scheduling algorithm. 66
3. NCS-451/JP/ 3
Hardware/Software Requirements
Hardware:
1. 700 MHz processor (about Intel Celeron or better)
2. 512 MB RAM (system memory)
3. 5 GB of hard-drive space (or USB stick, memory card or external
drive but see LiveCD for an alternative approach)
4. VGA capable of 1024x768 screen resolution
5. Either a CD/DVD drive or a USB port for the installer media
Software:
Ubuntu Desktop OS latest release/ Windows XP/7, Turbo C++ Compiler
Latest Version
4. NCS-451/JP/ 4
Objective of the Lab
1. To familiarize the learners with the Operating System.
2. To introduce LINUX basic commands
3. To get familiarize with vi editor.
4. To make students how to make simple programs in LINUX
5. To implement different CPU scheduling algorithms in C
6. To implement different page replacement algorithms in C
7. To implement Banker algorithms in C
5. NCS-451/JP/ 5
Linux Commands
These commands will work with most (if not all) distributions of Linux as well as most
implementations of UNIX. These are commonly use commands.
Index
1. Navigation - how to get around
o cd - changing directories
o ls - listing files
o pwd - knowing where you are
2. File Management - who needs a graphical file manager?
o cp - copying files
o ln - creating symbolic links
o mv - moving and renaming files
o rm - removing files
3. Monitoring Your System - to satisfy your insatiable curiosity
o tail - follow a file as it grows
o top - a program to see how your memory and CPU are holding up
o w - look at who's logged on
4. Shutting Down and Rebooting - you better know this, though you may not use it a lot
Navigation
Navigating around the files and directories of your hard drive could be a dreaded task for
you, but it is necessary knowledge. If you were a user of command prompt interfaces such as
MS-DOS, you'll have little trouble adjusting. You'll only need to learn a few new commands.
If you're used to navigating using a graphical file manager, I don't know how it'll be like, but
some concepts might require a little more clarification. Or maybe it'll be easier for you. Who
knows? Everyone is different.
cd
As you might already have guessed, the cd command changes directories. It's a very common
navigation command that you'll end up using, just like you might have done in MS-DOS.
You must put a space between cd and the ".." or else it won't work; Linux doesn't see the two
dots as an extension to the cd command, but rather a different command altogether. It'll come
to make sense if it doesn't already.
6. NCS-451/JP/ 6
ls
The ls letters stand for list. It basically works the same way as the dir command in DOS.
Only being a Unix command, you can do more with it. :-)
Typing ls will give you a listing of all the files in the current directory. If you're new to
Linux, chances are that the directories you are commonly in will be empty, and after the ls
command is run, you aren't given any information and will just be returned to the command
prompt (the shell).
There are "hidden" files in Linux, too. Their file names start with a dot, and doing a normal ls
won't show them in a directory. Many configuration files start with a dot on their file names
because they would only get in the way of users who would like to see more commonly used
items. To view hidden files, use the -a flag with the ls command, i.e. ls -a.
To view more information about the files in a directory, use the -l flag with ls. It will show
the file permissions as well as the file size, which are probably what are the most useful
things to know about files.
You might occasionally want to have a listing of all the subdirectories, also. A simple -R flag
will do, so you could look upon ls -R as a rough equivalent of the dir /s command in MS-
DOS.
You can put flags together, so to view all the files in a directory, show their permissions/size,
and view all the files that way through the subdirectories, you could type ls -laR.
pwd
This command simply shows what directory you're in at the moment. It stands for "Print
Working Directory". It's useful for scripting in case you might ever want to refer to your
current directory.
7. NCS-451/JP/ 7
File Management
A lot of people, surprisingly for me, prefer to use graphical file managers. Fortunately for me,
I wasn't spoiled like that and used commands in DOS. That made it a bit easier for me to
make the transition to Linux. Most of the file management Linux gurus do is through the
command line, so if you learn to use the commands, you can brag that you're a guru. Well,
almost.
cp
Copying works very much the same. The cp command can be used just like the MS-DOS
copy command, only remember that directories are separated with slashes (/) instead of
backslashes (). So a basic command line is just cp filename1 filename2.
There are other extensions to the cp command. You can use the -f command to force it. You
can use the -p command to preserve the permissions (and also who owns the file, but I'm not
sure).
You can move an entire directory to its new destination. Let's say you want to copy a
directory (and all of its contents) from where you are to be /home/jack/newdirectory/. You
would type cp -rpf olddirectory /home/jack/newdirectory. To issue this command you
would have to be in the directory where the subdirectory "olddirectory" is actually located.
ln
A feature of linking files is available in Linux. It works by "redirecting" a file to the actual
file. It's referred to as a symbolic link. Don't confuse this term with the linking of programs,
which is when binary programs are connected with libraries that they need to load in order to
run.
The most simple way that I've ever used ln to create symbolic links is ln -s existing_file link.
Evidently there's a hard link and a symbolic link; I've been using a symbolic link all along.
You can also use the -f flag to force the command line to overwrite anything that might have
the symbolic link's file name already.
To remove a symbolic link, simply type rm symbolic_link. It won't remove the file that it's
linked to.
mv
The mv command can be used both to move files and to rename them. The syntax is mv
fileone filetwo, where "fileone" is the original file name and "filetwo" will be the new file
name.
8. NCS-451/JP/ 8
You can't move a directory that is located in one partition to another, unfortunately. You can
copy it, though, using cp -rpf, and then remove it with rm -rf later on. If you have only a
single partition that makes up your filesystem then you have very little to worry about in this
area.
rm
The rm command is used for removing files. You use it just like the del or delete command
in MS-DOS. Let's say you want to remove a file called foobar in your current directory. To
do that, simply type rm foobar. Note that there is no "Recycle Bin" like in Windows 95. So
when you delete a file, it's gone for good.
To delete something in some other directory, use the full path as the file name. For example,
if you want to delete a file called "windows" that's in the directory /usr/local/src/, you would
type rm /usr/local/src/windows.
To remove an entire directory and its contents, type rm -rf /directory where "/directory" is
the path to the directory that you want to delete. If you're wondering, the "rf" stands for
"recursive" and "force". Be very careful with this command, as it can wreak havoc easily if
misused.
Monitoring Your System
An important part of system administration (especially with your own system) is being able
to know what's going on.
tail
The program tail allows you to follow a file as it is growing. Most often, I use it to follow
/var/log/messages. I do that by typing tail -f /var/log/messages. Of course, you can use
anything else, including the other logs in /var/log/. Another file you may want to keep an eye
out for is /var/log/secure.
If you want to leave that running all the time, I recommend having some sort of terminal
program in X, logged in as root through su.
Another program you may want to look at is head. It monitors the top of the file specified,
instead of the bottom.
9. NCS-451/JP/ 9
top
This program shows a lot of stuff that goes on with your system. In the program, you can
type:
1. M for memory usage information
2. P for CPU information
3. q to quit
Once you try it, you can see that top shows you the memory usage, uptime, load average,
CPU states, and processes.
w
Typing w will tell you who is logged in. This can be helpful if you're the only one who uses
your computer and you see someone logged in that's not supposed to be.
Another alternative is who.
Shutting Down and Rebooting
To shut down your system, type shutdown -h now, which tells the shutdown
program to begin system halt immediately. You can also tell it to halt the system at a later
time, I think, but you'll have to consult the shutdown manual page for that (man shutdown).
To do a reboot, you can either type reboot or shutdown -r. You can also use the
famous Ctrl-Alt-Delete combination to reboot, which you might already be familiar with.
Shutting down and restarting properly (as described above) will prevent your
filesystem from being damaged. Filesystem damage is the most obvious of the consequences,
but there are probably other things out there that I don't know about. The point is, shut down
your system properly.
There are (rare!) cases in which the machine might lock up entirely, and prevent you
from being able to access a command prompt. Only then will your last resort be to do a
forced reboot (just pressing the restart button on the case).
10. NCS-451/JP/ 10
vi Editor Commands
General Startup
To use vi: vi filename
To exit vi and save changes: ZZ or :wq
To exit vi without saving changes: :q!
To enter vi command mode: [esc]
Counts
A number preceding any vi command tells vi to
repeat that command that many times.
Cursor Movement
h move left (backspace)
j move down
k move up
l move right (spacebar
[return] move to the beginning of the next line
$ last column on the current line
0 move cursor to the first column on the
current line
^ move cursor to first nonblank column on the
current line
w move to the beginning of the next word or
punctuation mark
W move past the next space
b move to the beginning of the previous word
or punctuation mark
11. NCS-451/JP/ 11
B move to the beginning of the previous word,
ignores punctuation
e end of next word or punctuation mark
E end of next word, ignoring punctuation
H move cursor to the top of the screen
M move cursor to the middle of the screen
L move cursor to the bottom of the screen
Screen Movement
G move to the last line in the file
xG move to line x
z+ move current line to top of screen
z move current line to the middle of screen
z- move current line to the bottom of screen
^F move forward one screen
^B move backward one line
^D move forward one half screen
^U move backward one half screen
^R redraw screen
( does not work with VT100 type terminals )
Inserting
r replace character under cursor with next
character typed
R keep replacing character until [esc] is hit
i insert before cursor
a append after cursor
12. NCS-451/JP/ 12
A append at end of line
O open line above cursor and enter append mode
Deleting
x delete character under cursor
dd delete line under cursor
dw delete word under cursor
db delete word before cursor
Copying Code
yy (yank)'copies' line which may then be put by
the p(put) command. Precede with a count for
multiple lines.
Put Command
brings back previous deletion or yank of lines,
words, or characters
P bring back before cursor
p bring back after cursor
Find Commands
? finds a word going backwards
/ finds a word going forwards
f finds a character on the line under the
cursor going forward
F finds a character on the line under the
cursor going backwards
t find a character on the current line going
forward and stop one character before it
T find a character on the current line going
backward and stop one character before it
; repeat last f, F, t, T
13. NCS-451/JP/ 13
Miscellaneous Commands
. repeat last command
u undoes last command issued
U undoes all commands on one line
xp deletes first character and inserts after
second (swap)
J join current line with the next line
^G display current line number
% if at one parenthesis, will jump to its mate
mx mark current line with character x
'x find line marked with character x
NOTE: Marks are internal and not written to the
file.
Line Editor Mode
Any commands form the line editor ex can be
issued upon entering line mode.
To enter: type ':'
To exit: press[return] or [esc]
14. NCS-451/JP/ 14
PROGRAM 01
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR IMPLEMENTING ‘ FIRST
COME FIRST SERVE ’ ALGORITHM.
Concept: Perhaps, First-Come-First-Served algorithm is the simplest scheduling algorithm is the
simplest scheduling algorithm. Processes are dispatched according to their arrival time on the ready
queue. Being a nonpreemptive discipline, once a process has a CPU, it runs to completion. The FCFS
scheduling is fair in the formal sense or human sense of fairness but it is unfair in the sense that long
jobs make short jobs wait and unimportant jobs make important jobs wait.
FCFS is more predictable than most of other schemes since it offers time. FCFS scheme is not
useful in scheduling interactive users because it cannot guarantee good response time. The code for
FCFS scheduling is simple to write and understand. One of the major drawback of this scheme is that
the average time is often quite long.
The First-Come-First-Served algorithm is rarely used as a master scheme in modern
operating systems but it is often embedded within other schemes.
Source code:
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,j,sum=0;
int arrv[10], ser[10], start[10], finish[10],wait[10], turn[10];
float avgturn=0.0,avgwait=0.0;
start[0]=0;
clrscr();
printf("n ENTER THE NO. OF PROCESSES:");
scanf("%d",&n);
15. NCS-451/JP/ 15
for(i=0;i<n;i++)
{
printf("n ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS %d: ",i+1);
scanf("%d%d",&arrv[i],&ser[i]);
}
for(i=0;i<n;i++)
{
sum=0;
for(j=0;j<i;j++)
sum=sum+ser[j];
start[i]=sum;
}
for(i=0;i<n;i++)
{
finish[i]=ser[i]+start[i];
wait[i]=start[i];
turn[i]=ser[i]+wait[i];
}
for(i=0;i<n;i++)
{
avgwait+=wait[i] ;
avgturn+=turn[i];
}
avgwait/=n;
avgturn/=n;
16. NCS-451/JP/ 16
printf("n PROCESS ARRIVAL SERVICE START FINISH WAIT TURN n");
for(i=0;i<n;i++)
{
printf("ntP%dt%d t %d t %d t %d t %d t %d n",i ,arrv[i],
ser[i], start[i], finish[i],wait[i],turn[i]);
}
printf("n AVERAGE WAITING TIME = %f tu",avgwait);
printf("n AVERAGE TURN AROUND TIME = %f tu",
avgturn);
getch();
}
17. NCS-451/JP/ 17
FCFS CPU Scheduling Output:
ENTER THE NO. OF PROCESSES:3
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 1: 0
3
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 2: 1
3
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 3: 2
2
PROCESS ARRIVAL SERVICE START FINISH WAIT TURN
P0 0 3 0 3 0 3
P1 1 3 3 6 3 6
P2 2 2 6 8 6 8
AVERAGE WAITING TIME = 3.000000 tu
AVERAGE TURN AROUND TIME = 5.666667 tu
18. NCS-451/JP/ 18
ENTER THE NO. OF PROCESSES:4
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 1: 1
2
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 2: 3
2
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 3: 1
5
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 4: 4
6
PROCESS ARRIVAL SERVICE START FINISH WAIT TURN
P0 1 2 0 2 0 2
P1 3 2 2 4 2 4
P2 1 5 4 9 4 9
P3 4 6 9 15 9 15
AVERAGE WAITING TIME = 3.750000 tu
AVERAGE TURN AROUND TIME = 7.500000 tu
19. NCS-451/JP/ 19
ENTER THE NO. OF PROCESSES:5
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 1: 1
2
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 2: 3
5
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 3: 2
6
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 4: 3
6
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 5: 5
3
PROCESS ARRIVAL SERVICE START FINISH WAIT TURN
P0 1 2 0 2 0 2
P1 3 5 2 7 2 7
P2 2 6 7 13 7 13
P3 3 6 13 19 13 19
P4 5 3 19 22 19 22
AVERAGE WAITING TIME = 8.200000 tu
AVERAGE TURN AROUND TIME = 12.600000 tu
20. NCS-451/JP/ 20
PROGRAM 02
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR IMPLEMENTING ‘
SHORTEST JOB FIRST ’ ALGORITHM.
Concept: Shortest-Job-First (SJF) is a non-preemptive discipline in which waiting job (or process)
with the smallest estimated run-time-to-completion is run next. In other words, when CPU is
available, it is assigned to the process that has smallest next CPU burst. The SJF scheduling is
especially appropriate for batch jobs for which the run times are known in advance. Since the SJF
scheduling algorithm gives the minimum average time for a given set of processes, it is probably
optimal.
The SJF algorithm favors short jobs (or processors) at the expense of longer ones. The obvious
problem with SJF scheme is that it requires precise knowledge of how long a job or process will run,
and this information is not usually available. The best SJF algorithm can do is to rely on user
estimates of run times.
Source code:
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,j,temp1,temp2,sum=0;
int pro[10],arrv[10],ser[10],start[10],finish[10],wait[10],
turn[10];
float avgturn=0.0,avgwait=0.0;
start[0]=0;
clrscr();
21. NCS-451/JP/ 21
printf("n ENTER THE NO. OF PROCESSES:");
scanf("%d",&n);
for(i=0;i<n;i++)
{
printf("n ENTER THE ARRIVAL TIME AND SERVICE TIME
OF PROCESS %d:",i+1);
scanf("%d%d",&arrv[i],&ser[i]);
pro[i]=i;
}
for(i=0;i<n;i++)
{
for(j=0;j<n-i-1;j++)
{
if(ser[j]>ser[j+1])
{
temp1=ser[j];
ser[j]=ser[j+1];
ser[j+1]=temp1;
23. NCS-451/JP/ 23
}
for(i=0;i<n;i++)
{
avgwait +=wait[i] ;
avgturn +=turn[i];
}
avgwait/=n;
avgturn/=n;
printf("n PROCESS ARRIVAL SERVICE START FINISH WAIT
TURN n");
for(i=0;i<n;i++)
{
printf("ntP%dt%d t %d t %d t %d t %d t %d n",
pro[i],arrv[i], ser[i], start[i], finish[i],wait[i],turn[i]);
}
printf("n AVERAGE WAITING TIME = %f tu",avgwait);
printf("n AVERAGE TURN AROUND TIME = %f tu" ,avgturn) ;
getch();
}
24. NCS-451/JP/ 24
SJF CPU Scheduling Output:
ENTER THE NO. OF PROCESSES:3
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 1:5
9
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 2:2
4
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 3:5
6
PROCESS ARRIVAL SERVICE START FINISH WAIT TURN
P0 2 4 0 4 0 4
P1 5 6 4 10 4 10
P2 5 9 10 19 10 19
AVERAGE WAITING TIME = 4.666667 tu
AVERAGE TURN AROUND TIME = 11.000000 tu
25. NCS-451/JP/ 25
ENTER THE NO. OF PROCESSES:4
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 1:2
3
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 2:9
1
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 3:3
3
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 4:5
2
PROCESS ARRIVAL SERVICE START FINISH WAIT TURN
P0 9 1 0 1 0 1
P1 5 2 1 3 1 3
P2 2 3 3 6 3 6
P3 3 3 6 9 6 9
AVERAGE WAITING TIME = 2.500000 tu
AVERAGE TURN AROUND TIME = 4.750000 tu
26. NCS-451/JP/ 26
ENTER THE NO. OF PROCESSES:5
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 1:1
5
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 2:2
3
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 3:4
5
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 4:6
1
ENTER THE ARRIVAL TIME AND SERVICE TIME OF PROCESS 5:5
2
PROCESS ARRIVAL SERVICE START FINISH WAIT TURN
P0 6 1 0 1 0 1
P1 5 2 1 3 1 3
P2 2 3 3 6 3 6
P3 1 5 6 11 6 11
P4 4 5 11 16 11 16
AVERAGE WAITING TIME = 4.200000 tu
AVERAGE TURN AROUND TIME = 7.400000 tu
27. NCS-451/JP/ 27
PROGRAM 03
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR IMPLEMENTING
‘ PRIORITY SCHEDULING ’ ALGORITHM.
Concept: Each process is assigned a priority, and priority is allowed to run. Equal-Priority
processes are scheduled in FCFS order. The shortest-Job-First (SJF) algorithm is a special case of
general priority scheduling algorithm.
Source code :
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,j,temp1,temp2,sum=0;
int pro[10],ser[10],start[10],finish[10],wait[10],prior[10], turn[10];
float avgturn=0.0,avgwait=0.0;
start[0]=0;
clrscr();
printf("n ENTER THE NO. OF PROCESSES:");
scanf("%d",&n);
for(i=0;i<n;i++)
{
printf("n ENTER THE SERVICE TIME AND PRIORITY OF PROCESS%d:",i+1);
scanf("%d%d",&ser[i],&prior[i]);
pro[i]=i;
29. NCS-451/JP/ 29
for(i=0;i<n;i++)
{ avgwait+=wait[i] ;
avgturn+=turn[i];
}
avgwait/=n;
avgturn/=n;
printf("n PROCESS SERVICE PRIORITY START FINISH WAIT TURN n");
for(i=0;i<n;i++)
{ printf("ntP%dt%d t %d t %d t %d t %d t %d n", pro[i],ser[i], prior[i],
start[i],finish[i],wait[i],turn[i]);
}
printf("n AVERAGE WAITING TIME = %f tu",avgwait);
printf("n AVERAGE TURN AROUND TIME = %f tu ", avgturn);
getch();
}
30. NCS-451/JP/ 30
Priority CPU Scheduling Output:
ENTER THE NO. OF PROCESSES:3
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS1:4
2
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS2:1
5
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS3:3
4
PROCESS SERVICE PRIORITY START FINISH WAIT TURN
P0 4 2 0 4 0 4
P1 3 4 4 7 4 7
P2 1 5 7 8 7 8
AVERAGE WAITING TIME = 3.666667 tu
AVERAGE TURN AROUND TIME = 6.333333 tu
31. NCS-451/JP/ 31
ENTER THE NO. OF PROCESSES:4
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS1:1
3
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS2:3
5
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS3:2
6
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS4:3
4
PROCESS SERVICE PRIORITY START FINISH WAIT TURN
P0 1 3 0 1 0 1
P1 3 4 1 4 1 4
P2 3 5 4 7 4 7
P3 2 6 7 9 7 9
AVERAGE WAITING TIME = 3.000000 tu
AVERAGE TURN AROUND TIME = 5.250000 tu
32. NCS-451/JP/ 32
ENTER THE NO. OF PROCESSES:5
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS1:4
2
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS2:3
6
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS3:1
6
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS4:2
7
ENTER THE SERVICE TIME AND PRIORITY OF PROCESS5:3
4
PROCESS SERVICE PRIORITY START FINISH WAIT TURN
P0 4 2 0 4 0 4
P1 3 4 4 7 4 7
P2 3 6 7 10 7 10
P3 1 6 10 11 10 11
P4 2 7 11 13 11 13
AVERAGE WAITING TIME = 6.400000 tu
AVERAGE TURN AROUND TIME = 9.000000 tu
33. NCS-451/JP/ 33
PROGRAM 04
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR IMPLEMENTING
‘ ROUND ROBIN SCHEDULING ’ ALGORITHM.
Concept: In the round robin scheduling, processes are dispatched in a FIFO manner but are
given a limited amount of CPU time called a time-slice or a quantum. If a process does not complete
before its CPU-time expires, the CPU is preempted and given to the next process waiting in a queue.
The preempted process is then placed at the back of the ready list.
Round Robin Scheduling is preemptive (at the end of time-slice) therefore it is effective in
time-sharing environments in which the system needs to guarantee reasonable response times for
interactive users. The only interesting issue with round robin scheme is the length of the quantum.
Setting the quantum too short causes too many context switches and lower the CPU efficiency. On
the other hand, setting the quantum too long may cause poor response time and appoximates FCFS.
Source code :
#include<stdio.h>
#include<conio.h>
void main()
{
int count=0,swt=0,stat=0,i,temp,sq=0;
int pro[10],st[10],bt[10],wt[10],tat[10],n,tq;
float atat=0.0,awt=0.0;
clrscr();
printf("n ENTER THE NO. OF PROCESSES:");
scanf("%d",&n);
for(i=0;i<n;i++)
34. NCS-451/JP/ 34
{
printf("n ENTER THE SERVICE TIME OF PROCESS %d:",i);
scanf("%d",&bt[i]);
st[i]=bt[i];
pro[i]=i;
}
printf("n ENTER THE TIME QUANTUM:");
scanf("%d",&tq);
while(1)
{
for(i=0,count=0;i<n;i++)
{
temp=tq;
if(st[i]==0)
{
count++;
continue;
}
if(st[i]>tq)
st[i]=st[i]-tq;
36. NCS-451/JP/ 36
printf("n PROCESS BURST TIME WAIT TURN n");
for(i=0;i<n;i++)
{
printf("ntP%dt%d t %d t%dn" ,
pro[i],bt[i],wt[i],tat[i]);
}
printf("n AVERAGE WAITING TIME = %f tu",awt);
printf("n AVERAGE TURN AROUND TIME = %f tu",atat);
getch();
}
37. NCS-451/JP/ 37
Round Robin CPU Scheduling Output:
ENTER THE NO. OF PROCESSES:3
ENTER THE SERVICE TIME OF PROCESS 0:30
ENTER THE SERVICE TIME OF PROCESS 1:40
ENTER THE SERVICE TIME OF PROCESS 2:20
ENTER THE TIME QUANTUM:10
PROCESS BURST TIME WAIT TURN
P0 30 40 70
P1 40 50 90
P2 20 40 60
AVERAGE WAITING TIME = 43.333332 tu
AVERAGE TURN AROUND TIME = 73.333336 tu
38. NCS-451/JP/ 38
ENTER THE NO. OF PROCESSES:4
ENTER THE SERVICE TIME OF PROCESS 0:12
ENTER THE SERVICE TIME OF PROCESS 1:20
ENTER THE SERVICE TIME OF PROCESS 2:9
ENTER THE SERVICE TIME OF PROCESS 3:5
ENTER THE TIME QUANTUM:5
PROCESS BURST TIME WAIT TURN
P0 12 24 36
P1 20 26 46
P2 9 25 34
P3 5 15 20
AVERAGE WAITING TIME = 22.500000 tu
AVERAGE TURN AROUND TIME = 34.000000 tu
39. NCS-451/JP/ 39
ENTER THE NO. OF PROCESSES:5
ENTER THE SERVICE TIME OF PROCESS 0:22
ENTER THE SERVICE TIME OF PROCESS 1:11
ENTER THE SERVICE TIME OF PROCESS 2:34
ENTER THE SERVICE TIME OF PROCESS 3:2
ENTER THE SERVICE TIME OF PROCESS 4:12
ENTER THE TIME QUANTUM:6
PROCESS BURST TIME WAIT TURN
P0 22 43 65
P1 11 26 37
P2 34 47 81
P3 2 18 20
P4 12 37 49
AVERAGE WAITING TIME = 34.200001 tu
AVERAGE TURN AROUND TIME = 50.400002 tu
40. NCS-451/JP/ 40
PROGRAM 05
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR IMPLEMENTING
‘BANKERS ALGORITHM‘.
Concept: This approach to the deadlock problem anticipates deadlock before it actually occurs.
This approach employs an algorithm to access the possibility that deadlock could occur and acting
accordingly. This method differs from deadlock prevention, which guarantees that deadlock cannot
occur by denying one of the necessary conditions of deadlock.
If the necessary conditions for a deadlock are in place, it is still possible to avoid deadlock by
being careful when resources are allocated. Perhaps the most famous deadlock avoidance algorithm,
due to Dijkstra, is the Banker’s algorithm. So named because the process is analogous to that used
by a banker in deciding if a loan can be safely made.
The Banker's algorithm considers each request as it occurs, and see if granting it leads to a safe
state. If it does, the request is granted, otherwise, it postponed until later.
SOURCE CODE:
#include<stdio.h>
#include<conio.h>
void main()
{
int clm[7][5],req[7][5],alloc[7][5],rsrc[5],avail[5],comp[7];
int first,p,r,i,j,prc,count,t;
clrscr();
count=0;
for(i=1;i<=7;i++)
41. NCS-451/JP/ 41
comp[i]=0;
printf("Enter the no of processes : ");
scanf("%d",&p);
printf("Enter the no of resource types : ");
scanf("%d",&r);
printf("Enter the claim for each process :n");
for(i=1;i<=p;i++)
{
printf("For process %d : ",i);
for(j=1;j<=r;j++)
{
scanf("%d",&clm[i][j]);
}
}
printf("Enter the allocation for each process :n");
for(i=1;i<=p;i++)
{
printf("For process %d : ",i);
for(j=1;j<=r;j++)
{
42. NCS-451/JP/ 42
scanf("%d",&alloc[i][j]);
}
}
printf("Enter total no of each resource : ");
for(j=1;j<=r;j++)
scanf("%d",&rsrc[j]);
for(j=1;j<=r;j++)
{
int total=0;
avail[j]=0;
for(i=1;i<=p;i++)
{total+=alloc[i][j];}
avail[j]=rsrc[j]-total;
}
do
{
for(i=1;i<=p;i++)
{
for(j=1;j<=r;j++)
{
45. NCS-451/JP/ 45
}
if(prc!=0)
{
printf("nProcess %d runs to completion!",prc);
count++;
for(j=1;j<=r;j++)
{
avail[j]+=alloc[prc][j];
alloc[prc][j]=0;
clm[prc][j]=0;
comp[prc]=1;
}
}
}while(count!=p+1 && prc!=0);
if(count==p)
printf("nThe system is in a safe state!!");
else
printf("nThe system is in an unsafe state!!");
getch();
}
46. NCS-451/JP/ 46
Banker Algorithm Output
Enter the no of processes : 3
Enter the no of resource types : 4
Enter the claim for each process :
For process 1 : 2
1
3
4
For process 2 : 5
6
7
2
For process 3 : 3
4
5
6
Enter the allocation for each process :
For process 1 : 2
3
4
5
For process 2 : 6
1
2
3
For process 3 : 4
47. NCS-451/JP/ 47
2
3
4
Enter total no of each resource : 1
8
9
4
Claim matrix: Allocation matrix: Request matrix:
2 1 3 4 2 3 4 5 0-2-1-1
5 6 7 2 6 1 2 3 -1 5 5-1
3 4 5 6 4 2 3 4 -1 2 2 2
Available resources are : -11 2 0 -8
The system is in an unsafe state!!
48. NCS-451/JP/ 48
Enter the no of processes : 3
Enter the no of resource types : 2
Enter the claim for each process :
For process 1 : 2
3
For process 2 : 1
2
For process 3 : 2
3
Enter the allocation for each process :
For process 1 : 1
1
For process 2 : 1
1
For process 3 : 0
1
Enter total no of each resource : 6
7
Claim matrix: Allocation matrix: Request matrix:
2 3 1 1 1 2
1 2 1 1 0 1
2 3 0 1 2 2
Available resources are : 4 4
Process 1 runs to completion!
Claim matrix: Allocation matrix: Request matrix:
49. NCS-451/JP/ 49
0 0 0 0 0 0
1 2 1 1 0 1
2 3 0 1 2 2
Available resources are : 5 5
Process 2 runs to completion!
Claim matrix: Allocation matrix: Request matrix:
0 0 0 0 0 0
0 0 0 0 0 0
2 3 0 1 2 2
Available resources are : 6 6
Process 3 runs to completion!
Claim matrix: Allocation matrix: Request matrix:
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
Available resources are : 6 7
The system is in a safe state!!
50. NCS-451/JP/ 50
PROGRAM 06
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR IMPLEMENTING
‘ FIRST IN FIRST OUT PAGE REPLACEMENT ’ ALGORITHM.
Concept: The simplest page-replacement algorithm is a FIFO algorithm. The first-in, first-out
(FIFO) page replacement algorithm is a low-overhead algorithm that requires little book-keeping on
the part of the operating system. The idea is obvious from the name – the operating system keeps
track of all the pages in memory in a queue, with the most recent arrival at the back, and the oldest
arrival in front. When a page needs to be replaced, the page at the front of the queue (the oldest
page) is selected. While FIFO is cheap and intuitive, it performs poorly in practical application. Thus,
it is rarely used in its unmodified form.
Source code:
#include<conio.h>
#include<stdio.h>
void main()
{ int i,j,n,a[50],frame[10],no,k,avail,count=0;
clrscr();
printf("n ENTER THE NO. OF PAGES: ");
scanf("%d",&n);
printf("n ENTER THE PAGE Reference String.: ");
for(i=1;i<=n;i++)
scanf("%d",&a[i]);
printf("n ENTER THE NO. OF FRAMES: ");
scanf("%d",&no);
for(i=0;i<no;i++)
frame[i]=-1;
52. NCS-451/JP/ 52
FIFO Page Replacement Algorithm Output
ENTER THE NO. OF PAGES: 5
ENTER THE PAGE Reference String.: 1
2
3
4
2
ENTER THE NO. OF FRAMES: 3
REF. STRING PAGE FRAMES
1 1 -1 -1
2 1 2 -1
3 1 2 3
4 4 2 3
2
NO. OF PAGE FAULTS : 4
53. NCS-451/JP/ 53
ENTER THE NO. OF PAGES: 7
ENTER THE PAGE Reference String.: 1
2
3
1
2
3
4
ENTER THE NO. OF FRAMES: 3
REF. STRING PAGE FRAMES
1 1 -1 -1
2 1 2 -1
3 1 2 3
1
2
3
4 4 2 3
NO. OF PAGE FAULTS : 4
54. NCS-451/JP/ 54
ENTER THE NO. OF PAGES: 6
ENTER THE PAGE Reference String.: 2
2
2
2
2
2
ENTER THE NO. OF FRAMES: 3
REF. STRING PAGE FRAMES
2 2 -1 -1
2
2
2
2
2
NO. OF PAGE FAULTS: 1
55. NCS-451/JP/ 55
PROGRAM 07
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR IMPLEMENTING
‘ LEAST RECENTLY USED PAGE REPLACEMENT ’ ALGORITHM.
Concept: The Least Recently Used replacement policy chooses to replace the page which has not
been referenced for the longest time. This policy assumes the recent past will approximate the
immediate future. The operating system keeps track of when each page was referenced by recording
the time of reference or by maintaining a stack of references.
Source code :
#include<stdio.h>
void main()
{
int q[20],p[50],c=0,c1,d,f,i,j,k=0,n,r,t,b[20],c2[20];
printf("Enter no of pages:");
scanf("%d",&n);
printf("Enter the reference string:");
for(i=0;i<n;i++)
scanf("%d",&p[i]);
printf("Enter no of frames:");
scanf("%d",&f);
q[k]=p[k];
printf("nt%dn",q[k]);
c++;
k++;
for(i=1;i<n;i++)
{
58. NCS-451/JP/ 58
LRU Page Replacement Algorithm Output
Enter no of pages:4
Enter the reference string:2
3
1
2
Enter no of frames:2
2
2 3
1 3
1 2
The no of page faults is : 4
59. NCS-451/JP/ 59
Enter no of pages:7
Enter the reference string:1
2
3
2
4
2
5
Enter no of frames:3
1
1 3
1 3 2
4 3 2
4 5 2
The no of page faults is : 5
60. NCS-451/JP/ 60
Enter no of pages:8
Enter the reference string:1
2
1
2
3
1
2
3
Enter no of frames:2
1
1 2
3 2
3 1
2 1
2 3
The no of page faults is : 6
61. NCS-451/JP/ 61
PROGRAM 8
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR
IMPLEMENTINGFIFO(FIRST IN FIRST OUT) DISK SCHEDULING.
Concept: All incoming requests are placed at the end of the queue. Whatever number that is
next in the queue will be the next number served. This algorithm doesn't provide the best results. To
determine the number of head movements we would simply find the number of tracks it took to
move from one request to the next.
SOURCE CODE:
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void main()
{
int a[20],n,i,t=0;
clrscr();
printf("Enter head pointer position:");
scanf("%d",&a[0]);
printf("nEnter number of disk request:");
scanf("%d",&n);
printf("nEnter request in order");
for(i=1;i<=n;i++)
{
scanf("%d",&a[i]);
if(a[i]<0)
63. NCS-451/JP/ 63
FCFS Disk Scheduling Algorithm Output:
Enter head pointer position:500
Enter number of disk request:4
Enter request in order100
200
400
300
Processing order: 500 100 200 400 300
Total Head Movement:800
64. NCS-451/JP/ 64
Enter head pointer position:200
Enter number of disk request:6
Enter request in order300
100
400
200
250
550
Processing order: 200 300 100 400 200 250 550
Total Head Movement:1150
65. NCS-451/JP/ 65
Enter head pointer position:200
Enter number of disk request:4
Enter request in order200
100
-300
INVALID INPUT
66. NCS-451/JP/ 66
PROGRAM 9
STATEMENT OF THE PROBLEM: TO WRITE A C PROGRAM FOR IMPLEMENTING
SSTF(SHORTEST SEEK TIME FIRST) DISK SCHEDULING.
Concept: In this case request is serviced according to next shortest distance
from the header position.
SOURCE CODE:
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>0
void main()
{
int a[20],b[20],d,n,i,j,temp,s,k=0,x=0,t=0;
clrscr();
printf("Enter head pointer position:");
scanf("%d",&a[0]);
printf("nEnter number of processes:");
scanf("%d",&n);
printf("nEnter processes in request order");
for(i=1;i<=n;i++)
{
69. NCS-451/JP/ 69
SSTF Disk Scheduling Algorithm Output
Enter head pointer position:100
Enter number of processes:4
Enter processes in request order200
100
500
200
Processing order: 100 100 200 200 500
Total Head Movement:400
70. NCS-451/JP/ 70
Enter head pointer position:500
Enter number of processes:6
Enter processes in request order400
300
200
600
700
600
Processing order: 500 400 300 200 600 600 700
Total Head Movement:800
71. NCS-451/JP/ 71
Enter head pointer position:700
Enter number of processes:7
Enter processes in request order500
600
300
-700
INVALID INPUT