...Linux Kernels and Shells Linux kernels and shells Windows and Mac computer systems have one central kernel that abstracts the hardware so the operating system can manage it. Linux is more customizable because it allows you to create your own kernel. I have been hired as an IT consultant and have been asked to write a manual on the kernel distributions of Linux. The kernel is a program that constitutes the central core of a computer operating system. It has complete control over everything that occurs in the system. The shell is the outermost part of the operating system thusly why it was given its name. The shell is a program that interacts with user commands while the kernel itself does not interact directly with the user, but instead it interacts with the shell and other programs as well as with the hardware devices on the system. While there are countless amounts of distributions available there is a distinct top five distributions that are used with Linux. The first one, rightly so as it is one of the earliest distributions that were created, is Red Hat. Red Hat is one of the most popular distributions for Linux, it is widely used for personal computers and with businesses also. It has a great community support division called the Fedora Core who does a great job with support and is a major reason for the popularity of Red Hat. The next distribution on the list is Debian. Debian is the most popular community created distribution for Linux. While it is really flexible...
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...central kernel that abstracts the hardware so the operating system can manage it. Linux is more customizable because it allows you to create your own kernel. You have been hired as an IT consultant and have been asked to write a manual on the kernel distributions of Linux. This requires the following deliverables: * Define the necessary components and functions of an operating system as they relate to the Kernel and the shell. * List the 5 most common distributions (there are over 600 at present). * After choosing the kernel, the choice of a shell also needs to be made. List at least 2 shells that are available for the kernel that you have selected. * Choose one of the shells, and discuss how you can perform a minimum of 20 commands or functions. There are an influx of available operating systems out there to choose from. Windows, Unix, IOS X, and Linux to name a few. I have been asked to write a brief manual on the kernel distributions of Linux that will include defining the necessary components and their relations to the kernel and shell, the five most common distributions, choosing a kernel and the specific compatible shells, and how to perform at least commands or functions. A kernel in its simplest definition the center of a computer operating system that provides basic services for all other parts of the operating system, it allocates time and memory to programs and handles the filestore and communications in response to system calls. A shell is an interface...
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...Linux interview questions What is Kernel? Explain the task it performs. Kernel is used in UNIX like systems and is considered to be the heart of the operating system. It is responsible for communication between hardware and software components. It is primarily used for managing the systems resources as well. Kernel Activities: The Kernel task manager allows tasks to run concurrently. Managing the computer resources: Kernel allows the other programs to run and use the resources Resources include i/o devices, CPU, memory. Kernel is responsible for Process management. It allows multiple processes to run simultaneously allowing user to multitask. Kernel has an access to the systems memory and allows the processes to access the memory when required. Processes may also need to access the devices attached to the system. Kernel assists the processes in doing so. For the processes to access and make use of these services, system calls are used. What is Linux Shell? What is Shell Script? Linux shell is a user interface used for executing the commands. Shell is a program the user uses for executing the commands. In UNIX, any program can be the users shell. Shell categories in Linux are: Bourne shell compatible, C shell compatible, nontraditional, and historical A shell script, as the name suggests, is a script written for the shell. Script here means a programming language used to control the application. The shell script allows different commands entered in the shell to be executed. Shell...
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...LINUX PROGRAMMING FINAL NOTES UNIT 1ST THESE NOTES ARE AS PER SYLLABUS & WILL HELP YOU TO ACHIEVE SUCCESS IN FINAL EXAM OF MCA 5TH SEMESTER. LETS START: UNIT 1ST Linux – The Operating System: Linux is one of popular version of UNIX operating System. It is open source as its source code is freely available. It is free to use. Linux was designed considering UNIX compatibility. It's functionality list is quite similar to that of UNIX. Linux is a free distributed implementation of a Unix-like Kernel Developed by Linus Torvalds at the University of Helsinki with the help of programmers across the Internet. Linux history: * Linux features: Following are some of the important features of Linux Operating System. * Portable - Portability means softwares can works on different types of hardwares in same way.Linux kernel and application programs supports their installation on any kind of hardware platform. * Open Source - Linux source code is freely available and it is community based development project. Multiple teams works in collaboration to enhance the capability of Linux operating system and it is continuously evolving. * Multi-User - Linux is a multiuser system means multiple users can access system resources like memory/ ram/ application programs at same time. * Multiprogramming - Linux is a multiprogramming system means multiple applications can run...
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...is free to obtain, use and change. 2. Why is Linux popular? Why is it popular in academia? Linux is portable, is based on standards, is written in C, has a kernel programming interface, can support many users 3. What are multiuser systems? Why are they successful? A multiuser system is a system designed for multiple user input and output. 4. What is the Free Software Foundation/GNU? What is Linux? Which parts of the Linux operating system did each provide? Who else has helped build and refine this operating system? Organizational sponsor of the GNU Project. Linux is the name of the operating system kernel developed by Linus Torvalds, which has since been expanded and improved by thousands of people on the Internet. 5. In which language is Linux written? What does the language have to do with the success of Linux? The C programing language 6. What is a utility program? A command; performs a task that is frequently related to the operating system. 7. What is a shell? How does it work with the kernel? With the user? A shell is a type of command prompt, it sends commands from the user to the kernel 8. How can you use utility programs and a shell to create your own applications? You can write a shell script, also called a shell program. Make the file executable and give the name of the file as a command. The shell then executes the commands in the file as though you had typed each command individually. 9. Why is the Linux file system referred to as hierarchical? Because...
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...modified. Why is Linux popular? Why is it popular in academia?Due to the operating system's distribution among universities, students were able to become used to it's sophisticated developing environment which helped these graduates succeed in the industry as UNIX was being spread throughout the world. What are multiuser systems? Why are they successful?Multiuser is a term that defines an operating system or application software that allows access by multiple users of a computer. They are so successful because they allow for collaborative projects to be conducted with much more ease and efficiency. What is the Free Software Foundation/GNU? What is Linux? Which parts of the Linux operating system did each provide? Who else has helped build and refine this operating system?The GNU is a completely free (in the freedom sense) operating system built by Richard Stallman and many of its components, except for the kernel, were completed in the early '90s. Linus Torvalds wrote the kernel for Linux, which was also intended to be a free operating system, in the early '90s. The two systems then were combined together to finish Linux, with it's original kernel and added features supplied by GNU. Linux was born off the internet with hundreds of people helping to develop it in its early years. In which language is Linux written? What does the language have to do with the success of Linux?Linux is written in the C programming language, and this helps Linux be portable because...
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...the same terms/licensing. 2. Why is Linux popular? Why is it popular in academia? -Linux is popular for a number of different reasons. Its free software that is portable because it’s written in C, has an amazing range of supported "peripherals", has a lot of software available, and has standardization (POSIX). It’s generally popular in academia because it’s a free, open-source, portable, sophisticated programming environment that computer science students could use as a learning platform. 3. What are multiuser systems? Why are they successful? -A multiuser system is an operating system that allows multiple users to access a single computer's resources. It’s successful because it’s hard for a single user to use 100% of a modern computer’s resources, and allows for greater efficiency. 4. What is the Free Software Foundation/GNU? What is Linux? Which parts of the Linux operating system did each provide? Who else has helped build and refine this operating system? -GNU stands for "GNU'S Not Unix", and it was designed to be a UNIX-like operating system developed by Richard Stallman. Linux is the name of operating system kernel developed by Linus Torvalds. GNU's tools aside the Linux kernel make the operating system known as “Linux” aka “GNU/Linux”. Thousands of people helped refine the operating system online. 5. In what language is Linux written? What does the language have to do with the success of Linux? -Linux is written in the C programming...
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...Lecture 1 – Linux introduction and basics Module 1. Linux introduction ♦ Linux distributions ♦ Linux kernel What is a Linux distribution? ♦ it is a collection of applications, packages, management, and features ♦ ♦ ♦ ♦ that run on top of the Linux kernel. The kernel is what all distributions have in common (it is sometimes customized by the distribution maintainers) If they are all “Linux”, why are there so many different names, and which do I choose?” You may have heard names like Red Hat, Fedora, Debian, Ubuntu Distributions differ in several ways, and three of the most important are: ► ► ► Purpose Configuration and packaging Support model What’s a kernel? ♦ As you already know from the Operating Systems course ► the kernel is the core of all computer operating systems ► is usually the layer that allows the operating system to interact with the hardware in your computer ♦ The kernel contains software that allows you to make uniform use of ► hard disk drives, ► network cards, ► RAM, ► and other hardware components. ♦ In the Linux world, the kernel is based on code originally developed by Linux’s founder, Finnish developer Linus Torvalds. Back to distributions – Purpose, Configuration, Support ♦ Purpose ► Different distributions are often designed for different purposes and provide different user experiences. ► Some distributions are designed as servers, others as desktops, and some are designed to perform particular functions, for example, as embedded...
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...Linux is one of popular version of UNIX operating System. It is open source as its source code is freely available. It is free to use. Linux was designed considering UNIX compatibility. It's functionality list is quite similar to that of UNIX. Components of Linux System Linux Operating System has primarily three components Kernel - Kernel is the core part of Linux. It is responsible for all major activities of this operating system. It is consists of various modules and it interacts directly with the underlying hardware. Kernel provides the required abstraction to hide low level hardware details to system or application programs. System Library - System libraries are special functions or programs using which application programs or system utilities accesses Kernel's features. These libraries implements most of the functionalities of the operating system and do not requires kernel module's code access rights. System Utility - System Utility programs are responsible to do specialized, individual level tasks. Linux Operating System Kernel Mode vs User Mode Kernel component code executes in a special privileged mode called kernel mode with full access to all resources of the computer. This code represents a single process, executes in single address space and do not require any context switch and hence is very efficient and fast. Kernel runs each processes and provides system services to processes, provides protected access to hardwares to processes. Support code...
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...Build Your Own Oracle RAC Cluster on Oracle Enterprise Linux and iSCSI (Continued) The information in this guide is not validated by Oracle, is not supported by Oracle, and should only be used at your own risk; it is for educational purposes only. 12. Create "oracle" User and Directories Perform the following tasks on both Oracle RAC nodes in the cluster! In this section we will create the oracle UNIX user account, recommended O/S groups, and all required directories. The following O/S groups will be created: Description | Oracle Privilege | Oracle Group Name | UNIX Group name | Oracle Inventory and Software Owner | | | oinstall | Database Administrator | SYSDBA | OSDBA | dba | Database Operator | SYSOPER | OSOPER | oper | We will be using the Oracle Cluster File System, Release 2 (OCFS2) to store the files required to be shared for the Oracle Clusterware software. When using OCFS2, the UID of the UNIX user " oracle" and GID of the UNIX group " oinstall" must be the same on both of the Oracle RAC nodes in the cluster. If either the UID or GID are different, the files on the OCFS2 file system will show up as "unowned" or may even be owned by a different user. For this article, I will use 501 for the " oracle" UID and 501 for the " oinstall" GID. Note that members of the UNIX group oinstall are considered the "owners" of the Oracle software. Members of the dba group can administer Oracle databases, for example starting up and shutting down databases. Members...
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...Chapter 1 Introduction to Linux At a Glance Class Notes Table of Contents • Overview • Objectives • Teaching Tips • Quick Quizzes • Class Discussion Topics • Additional Projects • Additional Resources • Key Terms • Technical Notes for Hands-On Projects Lecture Notes Overview Linux technical expertise is essential in today’s computer workplace as more and more companies switch to Linux to meet their computing needs. Thus, it is important to understand how Linux can be used, what benefits Linux offers to a company, and how Linux has developed and continues to develop. In the first half of this chapter, you will learn about operating system terminology and features of the Linux operating system, as well as the history and development of Linux. Later in this chapter, you will learn about the various types of Linux and situations in which Linux is used. Chapter Objectives In this chapter, you will learn to: • Understand the purpose of an operating system • Outline the key features of the Linux operating system • Describe the origins of the Linux operating system • Identify the characteristics of various Linux distributions and where to find them • Explain the common uses of Linux in industry today Quick Quiz 1 1. What term is used to describe a running program on Linux? a. Application b. Process c. Runtime d. Project 2. What is represented...
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...What is free software? List three characteristics of free software. 1- Distribution 2- Development 3- Collaboration. 2. Why is Linux popular? Why is it popular in academia? Because of it portability and it is free as Free Expression easy to manipulate and transport. Because of its portability and easy to manipulate. 3. What are multiuser systems? Why are they successful? Multi-user are the several individual user that can access one system that being physical machine or VM. They are popular because it help to centralize resources and energies and minimize security concerns. 4. What is the Free Software Foundation/GNU? What is Linux? Which parts of the Linux operating system did each provide? Who else has helped build and refine this operating system? The Free Software Foundation (www.fsf.org) is the principal organizational sponsor of the GNU Project. GNU developed many of the tools, including the C compiler, that are part of the NU/Linux Operating System. Linux is the name of an operating system kernel developed by Linus Torvalds and expanded and improved by thousands of people on the Internet. Torvalds’s kernel and GNU’s tools work Together as the GNU/Linux Operating System. 5. In which language is Linux written? What does the language have to do with the success of Linux? Linux was written in C language. C can be used to write machine-independent programs. A programmer who designs a program to be portable can easily move...
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...Carlos Espiritu 12/10/11 Week 1 homework Page 19 1. What is free software? List three characteristics of free software. Free software includes GNU/Linux, Apache, and some examples of free applications are: KDE, OpenOffice.org. all these application can be used for router/mobile phones..Etc. Linux is free and price plays a roll but not so crucial as other OS. Also source code is available, and software can be used for any purpose, also can be studied and changed. Linux software can be distributed and changed versions as well. 2. What are multiuser sytems? Why are they successful? A multiuser system allows each user at their work terminals to be connected to the computer. The operating system of computer assigns each user a portion of RAM and drives the computer’s time among various users; it is also called time sharing system. In other words, a multiuser system allows many users to simultaneously access the facilities of the host computer. This type of system is capable of having 100’s of users use this computer at once. The commonly used multiuser systems are: 1. LOCAL AREA NETWORK 2. WIDE AREA NETWORK 3. METROPOLITAN AREA NETWORK. 3. In what language is linux written? What does the language have to do with the success of linux? Linux is written in the C programming language and because it is written in the C language the language can be imbedded in all type of devices from TV’s, to PDA’s, cell phones, cable boxes for the reason of this language being so portable...
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...control and monitor jobs submitted by the users for execution to ensure efficient processing. All these functionalities are provided by the kernel of operating system. The operating system also acts as an interface between user and the computer hardware. Components of operating system enable the different part of a computer to work together. The interface provides user an environment to execute and use the computer resources in an efficient manner. The interface is also known as shell. Operating system has following components: a) Kernel b) Networking c) Security d) Shell Kernel is the core of the operating system and it acts as a bridge between application and the actual data processing done at hardware level. These facilities available to application processes through inter-process communication mechanisms and system calls. It provides the lowest-level abstraction layer for the resources that application software must control to perform its function. It also decides at a particular time which process should be allocated to the processor. It is also responsible for allocating memory to various processes. Shell is the software that provides an interface for an operating system to access the services of kernel. The primary purpose of shell is to execute another program. The user interface of the operating system is...
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...because of the powerful, efficient, stable and secure operating systems like LINUX. It has a capability of providing each user the same data ensuring total privacy from each user even while accessed by 100's of users simultaneously. 2. What is the Free Software Foundation/GNU? Linux? Which parts of the GNU/Linux operating system did each provide? Who else has helped build and refine this operating system? The Free Software Foundation (www.fsf.org) is the principal organizational sponsor of the GNU Project. GNU developed many of the tools, including the C compilers that are part of the GNU/Linux Operating Systems. Linux is the name of an operating system kernel developed by Linus Torvalds and expanded and improved What are multiuser by thousands of people on the Internet. Torvalds’s kernel and GNU’s tools work together as the GNU/Linux Operating System. 3. In what language is Linux written? What does the language have to do with the success of Linux? Linux is written in the C programming language and because it is written in the C language the language can be imbedded in all type of devices from TV’s, to PDA’s, cell phones, cable boxes for the reason of this language being so portable. 4. What is a shell? How does it work with the kernel? With the user? Shell is a piece of software that provides an interface for users of an operating system. Shell provides access to the services of a kernel. Shell makes the user’s job faster and easier in many ways. 5. What is a...
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