Linux 1

Why are there so many Linux distros?

Each Linux distribution has different purpose and use. Also, it is easy to make a Linux distribution.

What is a shell? How does it work with the kernel? with the user?

A shell is just another computer program. It is the main user interface to systems that are similar to Unix. When you work with the shell, handles are referred to as file descriptors. As when you work with the shell, the kernel automatically opens handles for standard input, standard output, and standard error before it runs a program. User can use shell as a programming language because the shell is an interpreter. It does not compile program written for it but rather interprets programs each time they are loaded from the disk

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?

Free Software Foundation is the principal organizational sponsor of GNU project. Distributions of Linux include the expected complement of UNIX utilities and contributed by programmers around the world. This is including the set of tools developed as part of the GNU project. Linus Torvalds developed operating system kernel of Linux and it is improved by a lot of people through the Internet.

What is free software? List three characteristics of free software.

Free software is software that users have freedom for distribution and changes. Free software is free to be (1) studied, (2) redistributed and (3) modified.

What are the key terms of the GNU General Public License?

In GNU, people have right to copy, modify and re-distrubute the code. However, people have to be careful when redistributing the same license with the code.

Why is Linux popular? Why is it popular in academia?

Linux is portable and it is based on C programming language which is highly structured language. Students can easily get access to the source code of the operating system and it is easy for students to read. Moreover, this is free so this is why it is popular in academia.

In which language is Linux written? What does the language have to do with the successful of Linux?

Linux operating system is written in mostly C programming language. This language is portable and it can be adapted to different machine and it meets special requirements so this made C language successful of Linux.

What is the difference between a multiprocessor and a multiprocessing system?

Multiprocessor is a system with two or more processors or CPUs. Multiprocessing is a system that can process one ore more tasks at a time.

What are multiuser systems? Why are they successful?

Multiuser systems are the concept that a computer can allow multiple users to use all of the system resources almost simultaneously. This system could save a lot of costs and could run many tasks. Multiuser systems have powerful, efficient, stable and secure characteristics so it could provide users with same data with secured privacy. This is why it became successful.

Why is the Linux filesystem referred to as hierarchical?

There is no drivers with assigned letters in GNU/Linux. Hard drive can be connected to any directory in the file system. Hierarchy structure is a root directory represented by "/" which expands to subdirectories forming hierarchical tree.

Approximately how many people wrote Linux? Why is this project unique?

Thousands of people have written and have contributed to Linux/GNU using the Internet. The project is unique because a project had never been attempted before.

Give an example of when you would want use a multiprocessing system.

Two or more tasks are being run at the same time.

List some of the best Linux distros.

Ubuntu, Mint, Elementary OS, Arch Linux, TAILS are best distributions.

What is a utility program?

Utility program is written by the GNU project. It is sometimes referred to as a command. This performs a task related to the operating system. This is available on the Internet.

What is a virtual machine? List some advantages of virtual machines.

Virtual machine is an emulation of a given computer system and VM is the abbreviation. Advantages: Multiple OS environments can exist on the same machine, isolated from each other at the same time. VM offers an instruction set architecture and this is different from real computer's. Virtual machine has easy maintenance, and has convenient recovery and availability.

How can you use utility programs and a shell to create your own applications?

Write a shell scripts under DOS. Utilities perform functions that are universally required by users. A shell script is command lines contained in file. Then, create a file executable with the name of the file. The commands are executed by the shell.