Operating
System
•An
OS is a program which acts as an interface between computer system users and
the computer hardware.
•It
provides a user-friendly environment in which a user may easily develop and
execute programs.
•Popular
OS – Linux, Unix, Microsoft DOS,
Microsoft Windows
95/98,XP,NT,ME,2000,vista,7,8,10
•A
computer system has some resources which may be utilized to solve a problem.
They are
•Memory
•Processor(s)
•I/O
•File
System
•The
OS manages these resources and allocates them to specific programs and users.
Services
provided by Operating System
•Process
Management
•Memory
Management
•File
Management
•Device
Management
•Concurrency
Control
LINUX BASICS
•Linux
is a 100% free operating system,
(Open Source Software )which is specially designed for multitasking, multi-user
networks that is similar to Unix. -Linux was created by Linus Torvalds in 1991.
Distributors
of Linux
•Red
Hat
•Debian
•Caldera
•Mandrake
•SuSE
•Slackware
Linux Architecture
•Shell
– user interface
examples :bash,sh,tcsh,csh,ksh
Utilities – commands
Application programs – GIMP, Firefox, Open Office
Kernel – Core of Linux
It controls the resources of a computer
Allocates them to different users and tasks
Interacts directly with the hardware
Linux file system
Types
of Users in Linux
1.Root/System Administrator
Special user having
permissions to control, modify and configure various resources on the system.
Assigns user accounts & passwords
Allocates storage
space
Assigns access
permissions
Prevents unauthorized
access
Prompt of root is
denoted by # mode
•. File Owner – Owner of the file
• denoted by ‘u’
•3. Group Owner – for team projects
–Denoted
by ‘g’
4. Other users –
users do not belong to particular group. Denoted by ‘o’
