1. Welcome!
OSAC program
Date:- 1st June 2012
What we are doing today ?
- Brief introduction to UNIX system.
- Categorized list of commands.
- Examples of different commands.
-prepared by : Kedar Bhandari
2. UNIX ?
In narrow sense :- time sharing operating
system kernel , a program that controls the
resources of a computer and allocates them
among its users.
-lets usres run their programs,
-controls peripheral devices,
-provides a file system that manages the long-
term storage of information such as
programs,data, and documents.
3. UNIX ? (contd.)
In broad sense :- not only the kernel but also
essential programs like compilers, editors,
command languages, programs for copying
and printing files, and so on.
Still more broadly :- Unix may even include
programs developed by you or other users to
be runon your system, such as tools for
document preparation, rutines for statistical
analysis, and graphics packages.
4. A word of advice :
”Don't be afraid to experiment ”
-If you are a beginner, there are very few
accidental things you can do to hurt yourself or
other users. So learn how things work by trying
them.
5. Terminal and typing
UNIX system is ful duplex
- the characters you type on the keyboard are
sent to the system, which sends them back to
the terminal to be printed on the screen.(echo
process).
- ordinary printing characters.
- some interpreet your typing, for eg. : the
RETURN key.
6. Terminal and typing (contd.)
- control characters.
: ctrl + m – RETURN key
: ctrl + d – tell a program that there is no more
input
: ctrl + g – rings the bell on the terminal
: ctrl + h – backspace
: ctrl + i – the TAB
: ctrl + c – Break
7. What is Shell?
The shell provides you with an interface to the
UNIX system. It gathers input from you and
executes programs based on that input. When
a program finishes executing, it displays that
program's output.
A shell is an environment in which we can run
our commands, programs, and shell scripts.
There are different flavors of shells, just as
there are different flavors of operating systems.
Each flavor of shell has its own set of
recognized commands and functions.
8. Different types of shell
* Bourne shell (sh)
* C shell (csh)
* TC shell (tcsh)
* Korn shell (ksh)
* Bourne Again SHell (bash)
9. System information commands
df -display filesystem
free
top
uname -a -system information
lsb_release -a -version information
ifconfig
iwconfig -wireless specific information
ps -processes running
10. System information commands
lspci -all PCI buses
lsusb -USB buses
lshal -devices of Hardware Abstraction
Layer
lshw -lists hardware in the system
11. Working with the file system
pwd
cd
- cd /
- cd ~
- cd ..
- cd -
- cd /var/cache
17. Using Wildcards
* - match any number of characters.
? - match any single character.
[characters] - match any of the character with in
the brackets.
[! characters] – match any characters that are
not listed.
18. Becoming Root
sudo -s -run a shell as root
sudo bash -o vi - run a specific shell as root
sudo -i - sets root's initial login
environment
sudo su - root - becomes root and run
root's longin
19. Mounting USB drive
$ cd /mnt/
$ su (required to enter your password)
# mkdir usbflash
# ls /mnt/
# mount /dev/sda1 /mnt/usbflash
# ls usbflash
# umount /dev/sda1 /mnt/usbflash
# exit