1. Introduction:

1.1 what is Linux?

1.2 Advantages of linux over the other operating system.

1.3 FAT, NTFS, EXT

1.4 Culture of free software.

History

The Unix operating system was conceived and implemented by Ken Thompson and Dennis Ritchie (both of AT&T Bell Laboratories) in 1969 and first released in 1970. Its availability and portability caused it to be widely adopted, copied and modified by academic institutions and businesses. Its design became influential to authors of other systems.

In 1983, Richard Stallman started the GNU project with the goal of creating a free UNIX-like operating system.As part of this work, he wrote the GNU General Public License (GPL). By the early 1990s there was almost enough available software to create a full operating system. However, the GNU kernel, called Hurd, failed to attract enough attention from developers leaving GNU incomplete.

Another free operating system project, initially released in 1977, was the Berkeley Software Distribution (BSD). This was developed by UC Berkeley from the 6th edition of Unix from AT&T. Since BSD contained Unix code that AT&T owned, AT&T filed a lawsuit (USL v. BSDi) in the early 1990s against the University of California. This strongly limited the development and adoption of BSD.

In 1985, Intel released the 80386, the first x86 microprocessor with 32-bit instruction set and MMU with paging.

In 1986, Maurice J. Bach, of AT&T Bell Labs, published The Design of the UNIX Operating System. This definitive description principally covered the System V Release 2 kernel, with some new features from Release 3 and BSD.

MINIX, a Unix-like system intended for academic use, was released by Andrew S. Tanenbaum in 1987. While source code for the system was available, modification and redistribution were restricted. In addition, MINIX's 16-bit design was not well adapted to the 32-bit features of the increasingly cheap and popular Intel 386 architecture for personal computers.

These factors and the lack of a widely-adopted, free kernel provided the impetus for Torvalds's starting his project. He has stated that if either the GNU or 386BSD kernels were available at the time, he likely would not have written his ownLinux is a Unix-like operating system that was designed to provide personal computer users a free or very low-cost operating system comparable to traditional and usually more expensive Unix systems. Linux has a reputation as a very efficient and fast-performing system. Linux's kernel (the central part of the operating system) was developed by Linus Torvalds at the University of Helsinki in Finland. To complete the operating system, Torvalds and other team members made use of system components developed by members of the Free Software Foundation for the GNU Project.

1.2 Advantages of Linux (why Linux?)

Low cost: There is no need to spend time and huge amount money to obtain licenses since Linux and much of it’s software come with the GNU General Public License. There is no need to worry about any software's that you use in Linux.

Stability:

Linux has high stability compared with other operating systems. There is no need to reboot the Linux system to maintain performance levels. Rarely it freeze up or slow down. It has a continuous up-times of hundreds of days or more.

Performance: Linux provides high performance on various networks. It has the ability to handle large numbers of users simultaneously.

Networking: Linux provides a strong support for network functionality; client and server systems can be easily set up on any computer running Linux. It can perform tasks like network backup more faster than other operating systems.

Flexibility: Linux is very flexible. Linux can be used for high performance server applications, desktop applications, and embedded systems. You can install only the needed components for a particular use. You can also restrict the use of specific computers.

Compatibility: It runs all common Unix software packages and can process all common file formats.

Wider Choice: There is a large number of Linux distributions which gives you a wider choice. Each organization develop and support different distribution. You can pick the one you like best; the core function's are the same.

Fast and easy installation: Linux distributions come with user-friendly installation.

Better use of hard disk: Linux uses its resources well enough even when the hard disk is almost full.

Multitasking: Linux is a multitasking operating system. It can handle many things at the same time.

Security: Linux is one of the most secure operating systems. File ownership and permissions make linux more secure.Open source: Linux is an Open source operating systems. You can easily get the source code for linux and edit it to develop your personal operating system.Today, Linux is widely used for both basic home and office uses. It is the main operating system used for high performance business and in web servers. Linux has made a high impact in this world.

Different Distros:a) Redhatlinux b) Open Suse c) Ubunto d) Linux Mint e) Fedora f) ArchLinux g) Sabayon h) Debian i) Mandriva j) Puppy Linux

Red Hat Enterprise Linux (RHEL) is a Linux-based operating system developed by Red Hat and targeted toward thecommercial market. Red Hat Enterprise Linux is released in server versions for x86, x86-64, Itanium, PowerPC and IBM System z, and desktop versions for x86 and x86-64. All of Red Hat's official support and training and the Red Hat Certification Programcenter around the Red Hat Enterprise Linux platform. Red Hat Enterprise Linux is often abbreviated to RHEL, although this is not an official designation.

The first version of Red Hat Enterprise Linux to bear the name originally came onto the market as "Red Hat Linux Advanced Server". In 2003 Red Hat rebranded Red Hat Linux Advanced Server to "Red Hat Enterprise Linux AS", and added two more variants, Red Hat Enterprise Linux ES and Red Hat Enterprise Linux WS.

While Red Hat uses strict trademark rules to restrict free re-distribution of their officially supported versions of Red Hat Enterprise Linux, Red Hat freely provides the source code for the distribution's software, both for free software whose license requires such publishing and open source software where this is not mandatory. As a result, several distributors have created re-branded and/or community-supported re-builds of Red Hat Enterprise Linux that can legally be made available, without official support from Red Hat.

Linux File Hierarchy Concepts

File System:

Subdirectories of the root directory Content

/bin Common programs, shared by the system, the system administrator and the users./boot The startup files and the kernel, vmlinuz. In some recent distributions also grub data. Grub is the GRand Unified Boot loader and is an attempt to get rid of the many different boot-loaders we know today.

/dev Contains references to all the CPU peripheral hardware, which are represented as files with special properties.

/etc Most important system configuration files are in /etc, this directory contains data similar to those in the Control Panel in Windows

/home Home directories of the common users./initrd (on some distributions) Information for booting. Do not remove!/lib Library files, includes files for all kinds of programs needed by the system and the users./lost+found Every partition has a lost+found in its upper directory. Files that were saved during

failures are here./misc For miscellaneous purposes./mnt Standard mount point for external file systems, e.g. a CD-ROM or a digital camera./net Standard mount point for entire remote file systems/opt Typically contains extra and third party software.

/proc A virtual file system containing information about system resources. More information about the meaning of the files in proc is obtained by entering the command man proc in a terminal window. The file proc.txt discusses the virtual file system in detail.

/root The administrative user's home directory. Mind the difference between /, the root directory and /root, the home directory of the root user.

/sbin Programs for use by the system and the system administrator./tmp Temporary space for use by the system, cleaned upon reboot, so don't use this for saving any

work!/usr Programs, libraries, documentation etc. for all user-related programs.

/var Storage for all variable files and temporary files created by users, such as log files, the mail queue, the print spooler area, space for temporary storage of files downloaded from the Internet, or to keep an image of a CD before burning it.

1.3 Culture of Free Software:

The free culture movement is a social movement that promotes the freedom to distribute and modify creative works in the form of free content by using the Internet and other forms of media.

The movement objects to overly-restrictive copyright laws. Many members of the movement argue that such laws hinder creativity. They call this system "permission culture".

Creative Commons is a well-known website which was started by Lawrence Lessig. It lists licenses that permit sharing under various conditions, and also offers an online search of various creative-commons-licensed productions.

The free culture movement, with its ethos of free exchange of ideas, is of a whole with the free software movement. Richard Stallman, the founder of the GNU project, and free software activist, advocates free sharing of information. He famously stated that free software means free as in “free speech”.

Absolute Path and Relative Path

Absolute Path:

- Begins with “/”

- Gives complete round map to file location.

Eg: /usr/share/doc/abc.html

Relative Path:

- Do not begin with “/”

- Specifies location relative to current working dir.

Some basic commands:

- Changing directories:

$cd(change directory)

Syntax: cd <dir name>

Eg: $cd Nepal

$cd – goes to root directory.

$cd ..– goes to previous dir.

- Making new directory

$mkdir – to make new dir

Syntax: $mkdir<dir name>

Eg: $mkdirpokhara - creates directory pokhara.

About sudo

Allows a user with proper permissions to execute a command as the superuser or other user. GNU/Linux distributions use the “su” model to elevate user priveledges. SU (or Substitute User) is a simple command which allows you to assume another identity on your pc. It’s most-often use is to become the root or administrative user.

Sudo is a tool that supports allowing users to use their own credentials for privilege escalation. No two pas

swords. No root user. Furthermore, sudo already supports granularity. If Linux distributions used sudo instead of su by default, you wouldn’t have to give out the root password to anyone who needed to become an administrator

Examples

$su -u hope ls ~hope

List the contents of the hope directory as the hope user.