|
|
|
Modern Operating Systems by Herbert Bos and Andrew S. Tanenb...
Modern_Operating_Systems_by_Herbert_Bos_and_Andrew_S._Tanenbaum_4th_Ed.pdf
Showing 754 out of 1137
Modern Operating Systems by Herbert Bos and Andrew...
Modern_Operating_Systems_by_Herbert_Bos_and_Andrew_S._Tanenbaum_4th_Ed.pdf-M ODERN O PERATING S YSTEMS
Modern Operating Systems by Herbert...
Modern_Operating_Systems_by_Herbert_Bos_and_Andrew_S._Tanenbaum_4th_Ed.pdf-M ODERN O PERATING S YSTEMS
Page 754
SEC. 10.2
OVERVIEW OF LINUX
723
10.2 OVERVIEW OF LINUX
In this section we will provide a general introduction to Linux and how it is
used, for the benefit of readers not already familiar with it. Nearly all of this mater-
ial applies to just about all UNIX variants with only small deviations. Although
Linux has several graphical interfaces, the focus here is on how Linux appears to a
programmer working in a shell window on X.
Subsequent sections will focus on
system calls and how it works inside.
10.2.1 Linux Goals
UNIX was always an interactive system designed to handle multiple processes
and multiple users at the same time.
It was designed by programmers, for pro-
grammers, to use in an environment in which the majority of the users are rel-
atively sophisticated and are engaged in (often quite complex) software develop-
ment projects.
In many cases, a large number of programmers are actively cooper-
ating to produce a single system, so UNIX has extensive facilities to allow people
to work together and share information in controlled ways. The model of a group
of experienced programmers working together closely to produce advanced soft-
ware is obviously very different from the personal-computer model of a single
beginner working alone with a word processor, and this difference is reflected
throughout UNIX from start to finish. It is only natural that Linux inherited many
of these goals, even though the first version was for a personal computer.
What is it that good programmers really want in a system?
To start with, most
like their systems to be simple, elegant, and consistent. For example, at the lowest
level, a file should just be a collection of bytes.
Having different classes of files for
sequential access, random access, keyed access, remote access, and so on (as main-
frames do) just gets in the way. Similarly, if the command
ls
A
*
means list all the files beginning with ‘‘A’’,then the command
rm
A
*
should mean remove all the files beginning with ‘‘A’’ and not remove the one file
whose name consists of an ‘‘A’’ and an asterisk. This characteristic is sometimes
called the
principle of least surprise
.
Another thing that experienced programmers generally want is power and flex-
ibility. This means that a system should have a small number of basic elements that
can be combined in an infinite variety of ways to suit the application. One of the
basic guidelines behind Linux is that every program should do just one thing and
do it well. Thus compilers do not produce listings, because other programs can do
that better.
Finally, most programmers have a strong dislike for useless redundancy. Why
type
copy
when
cp
is clearly enough to make it abundantly clear what you want? It
Ace your assessments! Get Better Grades
Browse thousands of Study Materials & Solutions from your Favorite Schools
Concordia University
Concordia_University
School:
Operating_Systems
Course:
Great resource for chem class. Had all the past labs and assignments
Leland P.
Santa Clara University
Introducing Study Plan
Using AI Tools to Help you understand and remember your course concepts better and faster than any other resource.
Find the best videos to learn every concept in that course from Youtube and Tiktok without searching.
Save All Relavent Videos & Materials and access anytime and anywhere
Prepare Smart and Guarantee better grades
Know more
Students also viewed documents
lab 18.docx
lab_18.docx
Course
Course
3
Module5QuizSTA2023.d...
Module5QuizSTA2023.docx.docx
Course
Course
10
Week 7 Test Math302....
Week_7_Test_Math302.docx.docx
Course
Course
30
Chapter 1 Assigment ...
Chapter_1_Assigment_Questions.docx.docx
Course
Course
5
Week 4 tests.docx.do...
Week_4_tests.docx.docx
Course
Course
23
Week 6 tests.docx.do...
Week_6_tests.docx.docx
Course
Course
106
