Table Of Content

Operating System Concepts and Basic Linux Commands i Publishing-in-support-of, EDUCREATION PUBLISHING RZ 94, Sector - 6, Dwarka, New Delhi - 110075 Shubham Vihar, Mangla, Bilaspur, Chhattisgarh - 495001 Website: www.educreation.in ________________________________________________________________ © Copyright, Authors All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form by any means, electronic, mechanical, magnetic, optical, chemical, manual, photocopying, recording or otherwise, without the prior written consent of its writer. ISBN: 978-1-5457-0850-7 Price: `275.00 The opinions/ contents expressed in this book are solely of the authors and do not represent the opinions/ standings/ thoughts of Educreation or the Editors . The book is released by using the services of self-publishing house. Printed in India ii Operating System Concepts and Basic Linux Commands Shital Vivek Ghate EDUCREATION PUBLISHING (Since 2011) www.educreation.in ii i iv Content List Sr. Content Page 1. INTRODUCTION TO OPERATING SYSTEM 1.1 Introduction 1 1.2 The operating system performs 2 resource management 1.3 Structure of operating system 4 1.4 Components of computer system 5 1.5 Services Provided By Operating 6 System 1.6 Types of Operating System 7 A) Serial Processing System 7 B) Batch Processing System 8 C) Single Processor System 12 D) Multi Processor System 14 E) Multiprogramming System 16 F) Time Sharing System 18 G) Multitasking System 19 H) Parallel Processing System 21 I) Distributed system 22 J) Clustered Systems 24 K) Real Time System 25 v 2. PROCESS & THREADS 2.1 Process concept 28 2.2 Process 29 2.2.1 Process control block 29 2.2.2 Process State 30 2.3 Operations on Processes 32 2.3.1 Create a new Process 32 2.3.2 Terminate an Existing Process 33 2.3.3 Suspend execution 34 2.3.4 Send a signal or message 34 2.4 Concurrent process 34 2.5 Threads 35 2.6 Multithreading 37 2.7 CPU scheduling 40 2.7.1 Scheduling queues 40 2.7.2 Schedulers 41 2.7.3 Context Switch 43 2.7.4 CPU & I/O burst cycle 44 2.8 Scheduling Criteria 45 2.9 Scheduling Algorithms 46 2.9.1 First-Come, First-Served 46 Scheduling 2.9.2 Shortest-Job-First Scheduling 49 2.9.3 Preemptive SJF scheduling 50 algorithm (shortest-remaining-time- first) 2.9.4 Priority Scheduling 52 2.9.5 Round-Robin Scheduling 53 3. DEAD LOCK & MEMORY MANAGEMENT 3.1 Resource-Allocation Graph 58 vi 3.2 Conditions for deadlock 60 3.3 Deadlock Prevention 61 3.3.1 Mutual Exclusion 61 3.3.2 Hold and Wait 62 3.3.3 No Preemption 62 3.3.4 Circular Wait 63 3.4 Deadlock Avoidance 64 3.4.1 Banker‘s algorithm 65 3.4.2 Safety Algorithm 66 3.4.3 Resource-Request Algorithm 67 3.5 Deadlock Detection 67 3.5.1 Single Instance of Each 68 Resource Type 3.5.2 Several Instances of a 69 Resource Type 3.6 Recovery from deadlock 71 3.6.1 Process Termination 71 3.6.2 Resource Preemption 71 3.7 Logical- versus Physical-Address 73 Space 3.8 Swapping 75 3.9 Memory Protection 76 3.10 Memory allocation methods 77 3.10.1 Single Partition allocation 77 3.10.2 Multiple partitioning 77 3.10.2.1 Fixed equal 78 multiple partitioning 3.10.2.2 Fixed variable 79 multiple partitioning vii 3.10.2.3 Dynamic 82 multiple partitioning 3.11 Compaction 85 3.12 Paging 86 3.12.1 Shared Pages 88 3.13 Segmentation 89 3.13.1 Segmentation with paging 92 3.14 Demand Paging 94 3.15 Page fault 94 3.16 Page replacement algorithm 95 3.16.1 FIFO Page Replacement 95 3.16.2 Optimal page-replacement 97 algorithm 3.16.3 Least recently used Page 98 replacement 4. FILE SYSTEM & INTRODUCTION TO LINUX OPERATING SYSTEM 4.1 File Concept 100 4.2 File Attributes 101 4.3 Operations on Files 101 4.4 Types of files 103 4.5 Access Methods 104 4.5.1 Sequential access method 104 4.5.2 Direct Access 105 4.5.3 Other access methods 106 4.6 Free-Space Management 107 4.6.1 Bit Vector 108 4.6.2 Linked List 108 4.6.3 Grouping 109 4.6.4 Counting 109 viii 4.7 Allocation methods 109 4.7.1 Contiguous allocation method 109 4.7.2 Linked allocation 111 4.7.3 Indexed allocation 113 4.8 Directory structure 115 4.8.1 Single-Level Directory 116 4.8.2 Two-Level Directory 117 4.8.3 Tree-Structured Directories 118 4.8.4 Acyclic-Graph Directories 119 4.8.5 General Graph Directory 120 4.9 Structure Of Linux Operating System 122 4.10 Logging In And Logging Out 123 4.11 Directory Structure 124 4.12 Naming Files and Directory 127 5. SHELL AND BASIC LINUX COMMANDS 5.1 Shell 130 5.2 Changing the running shell 132 5.3 Shell Prompt 132 5.3.1 Changing the shell prompt 133 5.4 Creating user account 134 5.5 Basic syntax for command 136 5.6 Creating alias for long command 137 5.7 Input/output Redirection 137 5.7.1 Redirecting Standard Output 138 5.7.2 Appending standard output 140 5.7.3 Redirecting Standard Input 140 5.7.4 Pipe lines 141 5.7.5 Filters 141 5.8 Listing files and directories: (ls 145 command) ix