Dear Mr. Dipankar Das,
Here is a very simple minded answer --- the files are protected.
And what do I mean by this ? Linux is a multiuser, (multitasking)
operating system; I deliberately kept the latter in brackets, for the
former implies the latter but the latter does not, as an example of OS
on MAC. Now, for reasons of security --- in the sense that no user
should be allowed to access any other user's files, every user is
classified into three groups --- the owning group, called Owner, the
Working Group, called Group, and the Rest of the world, called Others.
For instance, if you are an user, working in the Dept. of Artificial
Intelligence in an University which has several other Departments, and I
am there in the Dept. of Mathematics, then you make the Owning group,
the Dept. of Artificial Intelligence is your Group, and myself and many
others of the same University belong to the Others group. Now, each file
can be given three basic operations --- you can Read it, you can Write
on it (thereby implying you can change it, fully or partially, and hence
also delete it !) and lastly you can eXecute the file, if it is an
executable file. Thus, if you give each of the groups --- Owner, Group,
Others these three kind of permissions or do not give, tha for each file
you have at most 2**9 = 512 different permissions possible. This
permission string has another indicator indicating what kind of file is
it --- whether it is a directory, regular file, device, system device
etc... Thus, to each file is associated a number, which can take at
least 512 * 5 = 2560 possibilities !
Further, everything in Unix is considered as a file, and thus the
moment some executable starts working, first it shall have its own
permissions, and do work on files that have compatible file permissions.
Thus, theoretically, it is very difficult to actually have a virus
program act on a Unix filesystem.
Well, this is a very very simple minded description from a layman.
There are many well qualified in the list who shall provide you with
more enlightening answers, from which I shall also learn many things.
Hoping for a nice thread on this.
Thanking you,
On Friday, September 20, 2002, at 07:07 , dipankar das wrote:
> Hello Friends
> I am not even a beginner, just beginning to begin in the world of
> linux. One
> carrot that Tathagata Banerjee, my young friend, allured me with, was
> the
> peaceful sleep without the threat of yet another virus attack eating
> into my
> hard-toiled megabytes of work over the last ten years or so.
> Now, why this difference? And how? Why Linux is not vulnerable to virus
> or
> worm or anything, the way all MS systems are, systems that I have lived
> with
> all these years?
> Can you tell me that, please, and for Linux's sake, at least for the
> sake of
> understanding it by this mid-forty young newcomer to this world, make it
> free of hard jargon as far as possible.
> Dipankar Das
>
>
> --
> To unsubscribe, send mail to [EMAIL PROTECTED] with the body
> "unsubscribe ilug-cal" and an empty subject line.
> FAQ: http://www.ilug-cal.org/help/faq_list.html
>
>
------
Partha Pratim Ghosh
--------------------------------------------------------------------------------
Office : Room 414
Department of Mathematics and Applied Mathematics
University of Cape Town
Rondebosch 7701
Cape Town
South Africa
Telephone : 021-650 5734
---------------------------------------------------------------------------------
Residence : 10, Kingsbury Park
Rondebosch 7701
Cape Town
South Africa
---------------------------------------------------------------------------------
"Mathematics is a game, play it..."
"Algebra : Analysis :: Anatomy : Physiology"
"Only Topology is boring and only algebra is dull; it is their alloy
that is more interesting..."
---------------------------------------------------------------------------------
--
To unsubscribe, send mail to [EMAIL PROTECTED] with the body
"unsubscribe ilug-cal" and an empty subject line.
FAQ: http://www.ilug-cal.org/help/faq_list.html
