Introduction to Linux
June 1, 2005
What is Linux?
o Linux is a free, Unix-like, multi-user, multitasking operating system.
Linux can be acquired for free. Because there is little incentive for profit,
Linux programmers are very cooperative and share ideas with one another.
Linux derives most of its features from UNIX.
Many users may log onto a single Linux system simultaneously.
A Linux system may run multiple applications simultaneously.
Why Study Linux (pp. 2-3):
o There are many reasons to learn about the Linux operating system. In fact, it will be
difficult to earn a living in computing without a through knowledge of Linux.
o Linux is used in the following everyday activities:
Most Web servers are Linux-based.
Most movie special effects are produced on Linux systems.
Financial activities, such as stock and banking activities, are conducted on
The United States government and military make extensive use of Linux.
Universities use Linux-based systems for records, research, communications,
o Linux was designed for largely complicated tasks performed in networked
The Advantages of Linux:
o Affordability – You pay for technical support, documentation, CD-ROM, but never
pay for the software (the code itself).
o Stability – If an application crashes in Linux, it does not crash the entire system.
o Reliability – Because Linux is open source and many developments are made by
users, there is no pressure to release new applications or upgrades by a certain date.
o File System – On the file systems of other operating systems, files are broken into
smaller fragments that are stored in multiple locations around a hard disk, which
reduces the efficiency. File creation and deletion leads to more fragmentation, which
leads to lower hard disk efficiency.
o Server Influence – Linux was originally built as a server, not a desktop OS.
o Flexibility, Customization, and Configuration – Users may choose from different
shells, different GUIs, etc.
o Security – Securing Linux may take a little bit of extra knowledge, but that extra
knowledge usually leads to a more secure operating system. Because Linux is open
source, programmers around the world to develop patches whenever security holes
o Multi-user capabilities – Linux is built as a server and thus uses accounts. User
configurations can be stored, and upon login, all custom configurations for that user
will be loaded. Users are also given a home directory in which personal data may be
o Multi-tasking capabilities – Linux has the ability to handle and regulate many
processes running at the same time. Linux handles multitasking very well because its
memory allocation is designed to keep system lag at a minimum.
The Disadvantages of Linux:
o Because you must learn UNIX commands, it takes longer to learn about Linux.
o Printed instruction manuals and technical support is much harder to find.
o Configuring devices in Linux is generally more difficult.
o Linux does not have an abundance of commercial software, such as word-processing
software, Internet browsers, and games.
o The Linux GUI does not provide as much functionality as the Linux CLI (command
Linux Distributions (p.15):
o Vendors have sold Linux for many years. If Linux is free and open source, why
would anyone pay for it? People don’t pay for the software (the code), but they pay
for the technical support, the documentation, and the CD-ROM.
o Linux has been developed in bits and pieces by many programmers. These bits and
pieces must be grouped together in order to use Linux. The time and technical
knowledge to do this grouping is beyond most people. Linux distributions are used to
alleviate this problem.
o Many organizations offer Linux distributions and they differ primarily in the
packaging of these bits and pieces.
o As we mentioned earlier, many companies release many distributions of Linux. Each
distribution is different, so many Linux users try different versions to see which one
best fits their needs.
Major Linux Distributions:
o RedHat – probably the most popular
o Debian / GNU
History of Linux (pp. 14-15):
o Because Linux is a derivative of UNIX. Therefore, it is necessary to learn a little
history of Linux. UNIX was developed in 1970 and officially released and
distributed by AT&T Bell Labs in 1972.
o The University of California at Berkeley was one of the users of this 1972 version.
They added many new features and released a new version of UNIX, known as the
Berkeley Software Distribution (BSD), which remains popular today.
o Many other organizations have developed new versions of UNIX through the years.
Therefore, there are today many different versions of UNIX.
o All of these versions of UNIX were designed primarily for large computers used at
corporations and Universities. As personal desktop computers became popular
throughout the 1980s, most people found the PC version of UNIX inadequate.
o Developing an effective PC version of UNIX became a personal project for a 21-year
old Finnish computer science student named Linus Torvalds. He released the first
version of Linux in mid-September 1991. It was so basic that it was released as
o He continued to add features to Linux for the next three years. He released the first
official version (version 1.0) in March 1994.
o Linux grew quickly both in popularity and functionality for two reasons. First, Linux
has always been intended to be open source software. This meant that it could be
accessed, modified, and enhanced by anyone. Secondly, Linux was widely
distributed over the Internet. Therefore, thousands of programmers were able to
access, modify, and enhance Linux.
o A group of programmers based in North Carolina began to work on a Linux
distribution in the summer of 1994. Their goal was to develop a distribution that was
easy for common users to use and install. This distribution became Red Hat Linux,
the most popular distribution today.