This document provides an overview of the UNIX environment. It begins with an introduction to UNIX, including its history and key features such as multi-tasking and multi-user capabilities. It then covers the different shells in UNIX like Bourne, C, and Korn shells. It discusses popular UNIX distributions like Linux, FreeBSD, and Solaris. It also provides examples of basic UNIX commands for file manipulation, directory navigation, and viewing system information. References for further reading on UNIX are included at the end.

1. UNIX ENVIRONMENT
DESIGNED BY :
MITTINPREET SINGH NAYYAR
VIKAS K PRASAD

2.  Introduction to Unix
 History of Unix
 Salient features of Unix
 SHELL
 Distributions
 Installing VMware
 Basic Unix Commands
 Q&A
 References
Roadmap

3. INTRODUCTION TO UNIX
 A multi-tasking and multi-user Operating System
 Developed in 1969 at AT&T’s Bell Labs by
 Ken Thompson (Unix)
 Dennis Ritchie (C)
 Peter Neumann suggested their project is given the name UNIX.
 It is a portable operating system that is designed for both efficient
multi-tasking and multi-user functions. Its portability allows it to run on
different hardware platforms. It was written is C and lets user do
processing and control under a shell.
 Unix is case sensitive

4. HISTORY OF UNIX
 The history of UNIX starts from the project MULTICS (Multiplexed
Information and Computing Service) in 1965 conducted by AT&T,GE
& MIT funded by DOD(Dept. of Defense)USA.
 The main aim to develop UNIX was to develop and operating
system that could serve large Community of users and allow them to
share data if needed be. This never to be enterprise called MULTICS
 In 1969, ken Thompson and Dennis Ritchie released the first version
of Multiuser System Called UNIX. At that time Unix was not portable.
To remedy this Ken Thompson created a new language “B” but
language lacked some aspects. So in 1973 UNIX was Rewritten in
“C” Language by Ken Thompson. C Language was developed by
Dennis Ritchie.

5. SALIENT FEATURE OF UNIX
 Multiuser Capability
 Multitasking Capability
 Communication
 Security
 Portability

6. What is SHELL
A shell acts as an interface between the user and the system. As a
command interpreter, the shell takes commands that we give interpret
the command and then conveys them to the kernel which ultimate
executes them. You can imagine kernel as a monarch who is the
overall control of everything where as the shell as its emissary

7. TYPES Of SHELLS
 BOURNE SHELL
Steve Bourne Creation, known after him Bourne Shell is the most
popular. It comes with every Unix System
 C SHELL
This shell is a hit with those who are seriously into Unix programming,
created by Bill Joy, it had two advantage over Bourne Shell. It allows aliasing of
commands the other one is history feature.
 KORN SHELL
it is not widely used but is a powerful and superset of Bourne shell,
created by David Korn.
OTHER SHELLS
 ZSHELL
 BASH SHELL

8. SHELL Prompt of Ubuntu
To open the terminal in Ubuntu use can use the shortcut : ctrl + Alt + T

9. DISTRIBUTIONS
 Linux
 Minix
 FreeBSD
 OpenBSD
 NetBSD
 GNU Hurd
 Solaris
 SCO Unix
Conclusion
There are many free Unix like operating systems floating around out there and most if not all
of them can be found quickly with a simple internet search. The OS's I have listed above are,
in my opinion, the best. They are also all available to use for free unlike most of the others.
http://www.distrowatch.com

10. Ubuntu Distribution

11. BASIC COMMANDS
This command returns your username. Sounds useless, but
isn't. You may need to find out who it is who forgot to log
out somewhere, and make sure *you* have logged out.
Example: whoami
whoami

13. Man - Manual
In unix online help has been available since the beginning. In order to
access all the available help, you have to tell the shell where to look for
online help pages. This information is specified using the MANPATH. A
common setting is:
MANPATH=/usr/man:/usr/share/man
When you use the man command to request online help as follows, the
man command searches every directory given in the MANPATH for an
online help page corresponding to the topic you have requested.
$man who
In this case it looks for the online help page corresponding to the who
command

14. A snapshot of $man who

15. Passwd
 To change the password of the user we use passwd command
 Which ever password we create Unix stores it in /etc/passwd file.
 The password actually stored in Shadow File which is located in
etc/shadow.
 We can even cat this file on the screen
 lets you change your password, which you should do regularly (at
least once a year).
$cat /etc/passwd

18. cal - Calender
Display a conveniently-formatted calendar from the command line.
In general, if no options are given, cal displays the current month at the
command line.

21. Touch
 With this command we will learn how to create files
 With this we can create many files without storing anything in the
files. The size of the file is ZERO Bytes
Q Why do we use touch ?
A when we want to create several files quickly we use touch
command.
 Example: touch dinesh heena siddhi jatin

23. cat- concatenate
 If we want to store a few lines in a file while creating it we use cat
command. One’s you are through with typing content press the
keys : Ctrl + d . In Unix Ctrl + d indicates the EOF(End of File)
 To display the content of file under DOS we use type command.
 To see content of file we use the following command
 Umask 0022
Example : cat >dheeraj - for creating file
cat < dheeraj or cat dheeraj - will show you the output

25. cp- copy
Copies Files from one Directory or location to another file or directory.
Cp command takes the liberty to overwrite the file to the destination it
will not even give a warning.
Example:
$cp abc.c xyz.c mycfile.txt
$cp abc.c xyz.c
$cp /usr/aa16/chapter1 /usr/aa16/newbook/chap1
The last command when executed it will copy the chapter1 file to
/usr/aa16/newbook. When copied to this directory it would have the
name chap1 instead of chapter1

27. rm - remove
Remove Files from directory. It is wise to use the option rm -i, which will
ask you for confirmation before actually deleting anything.

29. Ls-list
ls --- lists your files
ls -l --- lists your files in 'long format', which contains lots of useful
information, e.g. the exact size of the file, who owns the file and who
has the right to look at it, and when it was last modified.
ls -a --- lists all files, including the ones whose filenames begin in a dot,
which you do not always want to see.
There are many more options, for example to list files by size, by date,
recursively etc.

32. mv - move or rename
 moves a file (i.e. gives it a different name, or moves it into a different
directory

34. Chmod- change mode

36. mkdir – make directory

38. cd – change directory

40. Pwd- print working directory

42. rmdir – remove directory

44. logname

46. uname

48. who

50. tty – tele terminal

51. ulimit

53. sort

55. wc

57. Head

59. tail

61. more
shows the first part of a file, just as much as will fit on one screen. Just hit
the space bar to see more or q to quit. You can use /pattern to search
for a pattern.

63. less

65. date
Shows the current date and time.

67. References
 Unix Shell Programming By Yashavant Kanetkar.
 Unix Concept and Application by Sumitabha Das.
 http://www.tutorialspoint.com/unix
 https://www.youtube.com/watch?v=nVt3Rst-
2H8&list=PL7B7FA4E693D8E790

68. Q&A SESSION