9 – Introduction to UNIX
(1) What is Unix? What is Linux?
• UNIX is a powerful operating system originally developed at AT&T Bell Labs.
• It is very popular among the scientific, engineering, and academic communities due to
its multi-user and multi-tasking environment, flexibility and portability, electronic mail
and networking capabilities, and the numerous programming, text processing and
scientific utilities available.
• The UNIX system is mainly composed of three different parts: the kernel, the file
system, and the shell.
• The kernel is that part of the system which manages the resources of whatever
computer system it lives on, to keep track of the disks, tapes, printers, terminals,
communication lines and any other devices.
• The file system is the organizing structure for data. The file system is perhaps the most
important part of the Linux operating system. The file system goes beyond being a
simple repository for data, and provides the means of organizing the layout of the data
storage in complex ways.
• The shell is the command interpreter. Although the shell is just a utility program, and is
not properly a part of the system, it is the part that the user sees. The shell listens to
your terminal and translates your requests into actions on the part of the kernel and
the many utility programs
• Linux is a freely available, open source, Unix-like operating System. Written originally
for the PC by Linus Torvalds (A young student in the University of Helsinki), with the
help of many other developers across the internet.
• Linux now runs on multiple hardware platforms, from the smallest to the largest, and
serves a wide variety of needs from servers to movie-making to running businesses to
user desktops.
(2) Explain the Features of the Unix in detail.
• The following features are provided by the UNIX operating System.
• Open Source
➢ Linux source code is freely available and it is community based development
project.
➢ Multiple teams are working in collaboration to enhance the capability of Linux
operating system and it is continuously evolving.
1
, 9 – Introduction to UNIX
• Multiuser capability
➢ In a multi user system the same computer resources hard disk, memory etc are
accessible to the many users.
➢ Users are given the different terminal to operate, a terminal in turn, is a keyboard
and a monitor. All the terminals are connected to the main computer whose
resources are available by all users.
➢ So the user at any of the terminals cannot use only the computer but also any
devices that may be attached like a printer.
• Multitasking capability
➢ It means that it is capable of carrying out more than one job at the same time it
allow you to type in a program in its editor while simultaneously executes some
other command you might have given earlier.
➢ Say for example you might have given earlier sort and copy a huge file this job will
perform in the background while in foreground you use editor.
➢ This is managed by dividing the CPU time between all processes being carrying out.
• Communication
➢ UNIX has the excellent communication with the users. The communication may be
within the network of a single main computer or between two or more such
computer network.
➢ The users can easily exchange mail, data, and programs through such networks.
• Security
➢ Unix Has the three provisions for protecting the data. The first is provided by
assigning the passwords and login names to the individual users and ensuring that
nobody has excess to your work.
➢ All the five have the read write and execute permissions to each file which decide
who can excess a particular file, which can modify and execute it.
➢ Lastly there is a file encryption utility which encodes your file into an unreadable
format so even if someone succeeds in opening it your secrets are safe.
• Portability
➢ Portability means software can works on different types of hardware in same way.
➢ It is one of the main reasons for the popularity of the Unix. It can be ported to
almost any computer system with only the minimum adoptions.
2
(1) What is Unix? What is Linux?
• UNIX is a powerful operating system originally developed at AT&T Bell Labs.
• It is very popular among the scientific, engineering, and academic communities due to
its multi-user and multi-tasking environment, flexibility and portability, electronic mail
and networking capabilities, and the numerous programming, text processing and
scientific utilities available.
• The UNIX system is mainly composed of three different parts: the kernel, the file
system, and the shell.
• The kernel is that part of the system which manages the resources of whatever
computer system it lives on, to keep track of the disks, tapes, printers, terminals,
communication lines and any other devices.
• The file system is the organizing structure for data. The file system is perhaps the most
important part of the Linux operating system. The file system goes beyond being a
simple repository for data, and provides the means of organizing the layout of the data
storage in complex ways.
• The shell is the command interpreter. Although the shell is just a utility program, and is
not properly a part of the system, it is the part that the user sees. The shell listens to
your terminal and translates your requests into actions on the part of the kernel and
the many utility programs
• Linux is a freely available, open source, Unix-like operating System. Written originally
for the PC by Linus Torvalds (A young student in the University of Helsinki), with the
help of many other developers across the internet.
• Linux now runs on multiple hardware platforms, from the smallest to the largest, and
serves a wide variety of needs from servers to movie-making to running businesses to
user desktops.
(2) Explain the Features of the Unix in detail.
• The following features are provided by the UNIX operating System.
• Open Source
➢ Linux source code is freely available and it is community based development
project.
➢ Multiple teams are working in collaboration to enhance the capability of Linux
operating system and it is continuously evolving.
1
, 9 – Introduction to UNIX
• Multiuser capability
➢ In a multi user system the same computer resources hard disk, memory etc are
accessible to the many users.
➢ Users are given the different terminal to operate, a terminal in turn, is a keyboard
and a monitor. All the terminals are connected to the main computer whose
resources are available by all users.
➢ So the user at any of the terminals cannot use only the computer but also any
devices that may be attached like a printer.
• Multitasking capability
➢ It means that it is capable of carrying out more than one job at the same time it
allow you to type in a program in its editor while simultaneously executes some
other command you might have given earlier.
➢ Say for example you might have given earlier sort and copy a huge file this job will
perform in the background while in foreground you use editor.
➢ This is managed by dividing the CPU time between all processes being carrying out.
• Communication
➢ UNIX has the excellent communication with the users. The communication may be
within the network of a single main computer or between two or more such
computer network.
➢ The users can easily exchange mail, data, and programs through such networks.
• Security
➢ Unix Has the three provisions for protecting the data. The first is provided by
assigning the passwords and login names to the individual users and ensuring that
nobody has excess to your work.
➢ All the five have the read write and execute permissions to each file which decide
who can excess a particular file, which can modify and execute it.
➢ Lastly there is a file encryption utility which encodes your file into an unreadable
format so even if someone succeeds in opening it your secrets are safe.
• Portability
➢ Portability means software can works on different types of hardware in same way.
➢ It is one of the main reasons for the popularity of the Unix. It can be ported to
almost any computer system with only the minimum adoptions.
2
