Operating systems

Lecture No. 5

Operating system

1. Appointment of the basic functions of the operating system.

Under the term "operational system"

programs, functions such as є control over victories and

rozpodil resources in the calculating system. We said that in

calculating systems є physical resources, that is, resources, such

tied with real possessions (magnetic disks, operational memory,

hour of robot processor). We also said that in the system for a successful

functions є logical (they call them virtual)

resources, tobto resources, as a viewer does not have real possession

to be aware, but not to be realized at the sight of deyakykh cats,

koristuvachev. Physical and logical resources

resources of the calculating system.

Be it the operating system (OS) is operating with daydreams,

both at once and from the ways of managing them are rich in what characterizes її

power. Before such issues can be understood by understanding a file, a process,

ob'єkta і etc. Skin OS has a lot of such issues. For example, in OS

Windows NT can bring an understanding of the object to such a point, and even through

Keruvannya is full of every possible function. Yaksho mi

wondering UNIX, then in such a day, in the first place, є

understanding the file, but in a different way, understanding the process.

The process is a day-to-day process, like a day-to-day

all OS. The process is the price of the program, as it has the right to power on resources.

Two programs are visible (so that the code is that dan, that

All resources are visible, as there is a program (there can be:

space operational memory, given to the outbuilding,

the rights of volodinnya with other resources, for example, lines of communication). Yaksho mnogini

resources, but there are two programs, they grow, then in all

we can talk about tsi programs, as about two processes, - tse one

process. Yaksho skin program has its own powerless resources, moreover, ci

if you can’t change, if you don’t, then we’re talking about two

processes.

That doesn’t matter, if there are no resources in decile processes

nepolzhniy peretin, then we have a dinner about vicarystannya, so

called, subordinate resources. Chastkovo we talked about the last

lectures: guess the butt from the attachment to the friend. We can have a bootie

processes, leather from yak yak yak own resource pristіy

a friend is at a skin moment for an hour you can turn to a whole resource from replacements

for a friend as information. Synchronization of robotic processes on the butt

attaching a friend to us one of the functions of the OS, which field in

control functions of processes. Let’s be surprised

before the keruvannya process.

Process control:

1. Management during the central hour

processor.

2. Management of "pidkachuvannyam" and the input buffer.

3. Management of resources, which are distributed.

The main problems of process control.

Perche - keruvannya vikoristannyam to the hour of the central processor

(CPU), because the problem is sometimes called the CPU plans, to control

Tim, at what moment is it from the factory?

CPU activity: which is the process of CPU activity.

The other is the management of the "pidkachuvannyam" and the input buffer. Acceptable situation,

if great number people, for example, the whole course, sit at computers,

and all of them immediately launched an account of the processes. In the system

masa zavdan was established (guaranteed more than a hundred). And everything is numbered

the system cannot be accepted for robots in multi-program mode.

tse zanadto bagato. In general, vipadku pretend to be so ranked as buffer introduction

tasks or the buffer of the entered processes, tobto the buffer in which accumulates

these are the processes that you can clean up on the cob of your crumbs by the processor. Vinikaє

the problem of the choice of processes from the buffer for the cob of the grain.

Tse zavdannya planuvannya buffer.

Now we can see the development of the plan “pidkachuvannya”. Processor

there are a few processes, and a lot of processes

real operative memory of those buildings. Vinnik's vipadkuє

the need for quality from the defunct facilities to be used for the call

zapam'yatovoy prist_y. And behind a clear algorithm, we can see

zavdannya? What will be the strategy of vidkachuvannya? Can be seen, for example, skin

guy zavdannya. How big-mens are you able to organize the process of seeing?

the problem.

The third is resource management, which is distributed. Є set of resources,

access to those at the singing moments of the hour

new processes. This is the very colossia with the attachment of a friend. One s

function, as it is rich in what is the meaning of the power of the OS, the price of the function,

I will take care of organizing the interaction of the processes and the vicarious

resources The problem of the butt with the attachment is easy for the friend to see, and the axis

Whenever two programs are programmed, there is a fragment of the operative memory, then a keruvannya

such a resource that can be distributed is a foldable resource.

Now wonder at the design of the OS. Practically be-yaka OS maє

Core concept. The kernel of the OS is in

part of the OS, as you do not take part in the processes of

presence in the operational memory) and operation in OS modes, or in

supervisor (at the very specialized mode, about which we talked

at the last lecture). The core includes the base and the management of the main

the nuances characteristic of a given OS, as well as a set

programs that provide a keruvannya with deyakim physical annexes. Have

functions of the core, zokrem, enter the processing of the pererivan.

Mi inode nazivatimemo programs, scho keruyut resources, drivers.

attachments (physical chi logical). For example, the OS kernel includes

I'll attach the driver to the operative.

calculating systems. The first rіven in the main warehouse is from drivers

physical annexes. Onset r_ven - management of logical

then in our schema there can be a driver for kerovans with files, like on

for the sake of it, tied with the drivers for managing logical disks, and those,

my own cherga, tied with the drivers of real physical attachments and so

Not necessarily, but the OS components work with the mode

supervisor, chi OS modes. Bagato components, which are logical

reach out from the distance from the nucleus, can do it at the snake

modes. So it is not obligatory itself, all components of the OS work with the resident

modes. As a rule, it is not necessary for functional functions.

Now let's move on to the presentation of the main functions of the OS.

Controlling the clock of the central processor.

As a matter of fact, there is an algorithm for selecting tasks for transmission

the activity of the CPU implementation in the OS, to lay down a lot of real exploitation

the power of the OS community. The vibration algorithm will increase the visibility

criteria of efficiency

robots OS. To that keruvannya vikoristanny hour CPU we are with you

clear and easy to see types of OS.

First situation. I have a large number of workshops or programs,

demand a great obshytuyu obschlyuvalnyy tediousness of the system. Tse ti zavdannya,

they call them bastard; the stench vimagayut a great lass

і it is not enough to spend time before the new outbuildings. Tsі zavdannya Mayut visit

one calculating system. What will be the criterion of efficiency

for robotic systems pid hour to see the package zydan? Yakiy nabir

parameters can be taken and said: if the stench is great - that is good, if

navpaki - is that rotten? For such a situation, the criteria for the efficiency of robots

calculating systems є steps for locking up the CPU. Yaksho vin is a little

idle (tobto practice in the mode of cleaning, and all the processes are engaged

obminom, for OS sorting out the hour), we can say, oh taka

the system is very effective. Tsiogo can reach the victorian

based on the planning algorithm, which is the case for the offensive.

We launch mo for processing that set of buildings, which we have є

the possibilities of the OS (or the maximum, or all the zavdannya),

multi-program mode. Algorithm for planning an hour of the CPU at a tsomu

If there will be an offensive: if the CPU is seen by one of the processes, then

the process of occupying the CPU until one of the following situations occurs:

1. Zvernennya to the outbuilding.

2. Completed the process.

3. Recording the fact of looping the process.

Yak tilka came alone with the situation, the control was transferred

the process. Number of control transfers from one process to

іnshomu minimized. That is, when transferring control from one process

on іnshіy OS maє viconati nabir deyakikh dіy, and tse vrata

hour, then there is a loss of minimization. Such a robotic OS mode

called batch mode. OS, yaka pratsyuє in this mode,

be called a batch OS.

Now the situation is obvious, if the number of people is significant

to be in the computer class and skin, of which the editor is

text. A copy of the text editor is tied to the skin from the terms.

We will be surprised if we will be using the system, as the planning algorithm will be installed,

vicladenia for the first vipadku. Acceptable, there are some of the coristas trocha

Sleep behind the terminal and did not see any kind of activity. CPU hour will be

tied to a cim process, which is not a vison exchange that is not

finished, oskіlki editor ready to robots. All in all

koristuvachi will be snarled for awakening asleep. To fold

freezing situation. Tse means, that is an algorithm that is good for the first

However, it is not suitable for the whole system to navigate for the presence of the necessary machine.

To that for the building, as the solution of the problems and the preservation of the great things

koristuvachіv obscruvalnyh services (interactive buildings),

These algorithms include one of the most important criteria for efficiency.

For such a system, the criteria for the hour of ochikuvannya koristuvach:

the moment, yak vin nadislav zamovlennya on vikonannya yakois diii, until the moment

revision of the system at the price of replacement. Chim an effective pratsyuє system, tim tse

The average statistical hour is the smallest for the system.

The situation is clear for another. The system has a deyake

a number of processes, and the production of a planner for a CPU hour is

rank, the hour of the reaction of the system to the power supply of koristuvach bulo

minimal, or take a guarantor. Get lost

scheme. The system has a singing parameter (t, which is called

quantum hour (zagalom, quantum hour - tse deyake value,

as you can change when the system is adjusted). All processless processes,

like being in multiprogramming, add two

p_dnomnogini. First, we store those processes that are not

ready to go ahead: for example, those processes that have replaced

on myself exchange and check on yo results. A є processes that are ready before

visonannya. The robot will work in such a way. That process

whichever at the moment the CPU is loaned to the hour,

nastaniya one znachnyh podiy:

1. Zvernennya from replacements for exchange.

2. Completed the process.

3. Drawing up the quantum seen by the given process

hour (t.

At the onset of one z cich, the planner OS vibrates

processes that are ready before being announced, a certain process and transfer of resources

CPU. And the vibrating process is based on the algorithm

planuvannya, like a buv vikoristany in a given specific OS. For example,

The process can be vibrated vaguely. Another way of playing the field is that

the last round of the processes, to be taken into

a robot from a collection of one of the processes, then the

An offensive order has been given to the process of those who are ready to go.

The third criterion, for which one should be found in Chergove Zavdannya, can be

hour, so the process is not serviced by the CPU. I have a problem with the system

You can choose the process that has the greatest hour. Qi algorithms

guilty of being implemented in the OS, and also, it stinks, but it’s simple, inappropriate

the system is practically ineffective, on itself (like this system є:

zokrema, at the same time the Windows family is awesome).

This type of OS is called OS by the hour. Vona pratsyuє in mode,

at any time, the hour of the reaction of the system on the power supply of the koristuvach is reduced. Have

ideals, for the reason that the hour of the power supply is minimal, at

koristuvach is guilty of creating illusions, all resources of the system

Give it to youmu.

Now we will be amazed at the same experience. Admittedly, we have є litak,

curing with an auto-pilot, which is an auto-pilot

derogation. Kozhen litak maє prilad, yaky vimiru visot vid

until the surface of the earth. Robot mode lіtaka takiy, scho keruvannya

with the functions of the given program, the computer is in use.

Otzhe, as the autopilot system, and so to decrease, the price system

maє kontrolyuvati visotu polotu. Central computer of tsyy l_tak

you can see the name of the plant: you can control the weight of the polot,

rіven firing at the tanks, as the indicators of the robots are moving too.

The management of the skin and of these functions takes care of their process. Acceptable, at

we have a package of OS, and we respectfully control the level of fire at the tanks. At

which, obviously, is the fault of the emergency situation

znizhuvatis, but the OS does not help.

Let's admit, we have a system every hour. One of the yokes

system and by the hour є ineffectiveness for the

the system has been transferred to a large number of changes from the process to

process, and tsya funkts_ya to complete the labor worker. The same situation: hanging

go to zero, and the OS is busy with rearranging the home table. Such

option can go.

For the creation of this kind, the establishment needs a plan. Have

a lot of vykoristovatsya, so called, OS real hour, the main

criterion for which є hour of guaranteed reaction of the system to

Winning of this and of the first step with a set in advance of the appointment

go. Tobto in the system є nabir podiy, on which the system is at

the situation will be reacted to process them for an hour in advance of assignments.

For our butt, this can be a good information from

the height of the sensor. Really for the OS of the whole class vikoristoyutsya to finish the simple

algorithms. All the planning of the field at the ts'omu criterion, tobto

guarantee the processing of the pod in an hour, so that I don’t change the person

threshold value. Ale OS for a real hour call your mother

a specific attachment, which is not the only way to start, we will forgive

the planning algorithm, and the internal power-up system.

Pidvodyachi deyaku between the functions of management vikoristannyam

hour of the CPU that planuvannya CPU, I grudge respect for two facts. The first fact

the same algorithms that are implemented in the planning systems

by the hour of the CPU, it’s a lot to start operating

calculating systems. I specially aiming the butt,

vicoristovuvati development OS for business purposes. Another fact. Mi looked three

types of OS types: systems and batch processing, systems and podil

system hour and real hour. On this day, you can talk about

those, scho the system is a real hour of the ocremy class OS. Guaranteed,

Windows OS is not keruvatie as objects, for those who have real

the hour is even more critical. It is also not keruvatime with such objects that OS

SOLARIS or LINUX, etc., besides, systems and not systems

real hour

First two modes, batch mode, for an hour, you can

such zalnoprinyat OS. Really, great and serious OS є

changing systems, tobto. the smell of presence in the elements of the CPU plan

both algorithms, which allow keruvati rakhunkovannyh zavdannymi, as well as algorithms,

how to allow keruvati with interactive staff or goodwill,

for any CPU requirement.

With the application of such organization of the planning of the CPU, you can

scheme. The planner was created on the yard scheme. Mi vvazhaєmo, scho

bezlichny zavdan that

Interactive tasks The first step is the first priority

classes of the building and for giving the CPU a list of useful tasks, or interactive

tasks. And the other rіven viznacha those who spoke in front of the tsim, tobto.

yak vibrati zavdannya in the boundaries of one class and yak yogo interrupt. Taka

The system can be replaced by an offensive rank. First rіven

planuvannya pratsyuvatime for the following principle: as long as there is no moment

zhodnogo interactive zavdannya, ready before the announcement (and in general it is

the situation, if they are busy editing the text), then the CPU

passed on to the rakhunkov zavdannya, and only one mind is given: yak tilki

I would like to appear one more interactively

keruvannya is transferred to the block of interactive buildings. Tse those, why should you

the first function of managing the processes.

Management of feeds and input buffers.

Here, the planning algorithms are required, but not so critical. Have

In real systems, most often the buffer is added to the buffer, tobto. that space

on the latest news, where do you see the information about the operational

memory is the buffer of the input processes. Tse persche respected.

Respect to a friend. Suchasnі OS to finish "linivі" and vіdkachuvannya

most often come not only blocks of memory of processes, but see

the whole process. There are two meals here: what is the criterion of replacement

the process is such a selection criterion from the buffer of the process that we

it is necessary to enter for processing multiprograms. Simplest option

Polyagaє at the victorian hour, perebuvannya at that chi іnshomu stanі. Have

the first vypadku, as mi virishuєmo nutrition about the process of active

I will start from the number of people who have been smashed into the area of ​​podkachuvannya, then we can

process, which you can find more

astronomy hour. Zvorotny process that, possibly symmetrical, tobto. mi

we can take from the buffer the entered processes in the process that is found there

to be found. As a matter of fact, it’s simple and real by planning algorithms, that

the stench can vidozminyuvatisya from different criteria. One s

criteria, as all the staff members are in different categories, so that you can

buti zavdannya OS - at the smell of looking at the front (i

in the middle of them there is an estimation algorithm for the hour of knowledge (there) and all

інші staff. This model is similar to the model of living injustice.

in suspensions, de є omnipotent people, as everything is allowed, but є

people who can and conceived.

Resource management, distributed.

Here it is meaningfully deprived of the problem, that is why it is concrete

We can see it from the UNIX OS stock.

Supposedly, є two processes, like working on a zagalny

space of operational memory. With a wide range of resources, it is possible to distribute

pratsyuvati in different modes, tobto. the situation is not enabled if two processes

really know on old cars, ale the stench tied with a field of operative

memory. Vinnik has a problem with buffering robots from memory,

In addition, on the skin of the machine, it has its own buffering mechanisms for reading.

I'll write it down. There is a disgusting situation here, if there is a physical

the memory of the real thing in the world. And also find out

deyakі problems for the OS, scho work on two machines.

The problem is coming. Come on є two processes, how to work on

one machine. Maє buti singing koshti, yaki allow

synchronize access to memory, how to distribute, to allow opening

say, for what kind of exchanges of skin and cleaning processes with an operational

the memory is correct. Tse means, for skin reading

Information from memory can be guaranteed that everything

koristuvachi, as they started to write in the memory, the same process

completed - it is the fault of the synchronization of the exchange with the memory, which is to be distributed.

For the sake of it, when a building is installed, it is often not needed

resources are distributed, like a memory, ale, b, processes,

as they function one hour, they could push a friend in

for one. Injection, analogous to the pererivan apparatus. For the implementation of the

bagatoh OS є for the transmission of signals between processes,

there is a deyak of the program of imitation of pererivan. One process seems to be -

send a signal to the process. In the process of making a change

vikonannya tsyogo process and transfer of control to the deyak

zoomed in function, as it is guilty of opratsyuvati signal removal. Tse

the third function of the OS.

I brutalize your respect for such OS functions, which pour on

exploitation characteristics. Really, be it OS, you can also take revenge on the majestic set

These are the functions that provide the system for the robot.

Lecture number 6

Past lectures talked about those who are practical

The operating system will not buffer the input / output. For good reason,

tse one of the main functions of the operating system. For an analogue struggle

free access to other components of the numerical system

the operating system to enter buffering at the interface,

yaka takozh virishuє problems and problems

synchronization with zalom (butt from attachment to friend). Zgladzhuvannya problems

access to the field in the fact that it is a practical skin operating system

MAK KESH-buffers, which accumulate the beast to the last memory

an attachment (VZP) similarly to hardware buffering in robotic operation

pam'yattyu. Tse allows the sutta to optimize the operating system.

I know the obviousness of such buffering є vimoga pinch

Visiting the operating system in front of the machine. Forward, pratsyuchi

with the MS-DOS operating system, you can open the computer whether it is

the hour, that kind of buffering at them is dumb. In operating systems

the Windows and UNIX type is inconsistent, just connect the machine when

a practical system, in general, it will become

a deyaka vrata information (oskilki, for example, moments of replacement

bezposeredno exchange is far from being lost). Buffering step

This is because of the real efficiency of the system. If our faculty has become

there is a Pentium, it appears, it is a robot with Windows 95

Practically dumb developmental difference between

486 Pentium processors. Don't talk about those who are effective

the system does not fit into the efficiency of robotics from external attachments. Yaksho

take the UNIX operating system, then the difference will be remembered, oskilki

here the processor's shvidcode is stronger than the flow of the robotic system,

nіzh for Windows 95, in addition to that in systems Windows 95 exchange s

zvnishnim nose is much more for the analysis of the deyakoi "dullness" of the algorithms

buffering robots from external attachments.

2. File system.

We told you that the skin from the operative systems of opera

by doing things, by one process. Є friend

Day, which is just as important - to understand the file. File system - tse

component of the operational system, which will ensure the organization of the stem,

sberіgannya and access to change sets of tributes. Price change

danikh are called files.

Basic File Authority

1. File - tse yakis ob'єkt, scho maє im'ya, and scho allows to operate from

the last of the deyakykh symbols, dozhin which lie in a specific

operating system.

2. Independence of the file from roztashuvannya. For robots with a specific file

mother doesn’t need information about rooting out the file on the last

attachments.

3. Set of functions for input / output. Practically dermal operating system

unambiguously viznachaє set of functions, which will not be able to exchange from the file. Call me

a whole set of functions to be stored from the next power supply:

1. Open the file for the robot. Visibility is possible anyway,

any new file. Can I see the file?

tse є zasib, schob centralized ogolosity

operating system, the file will be processed with specific

process. And you can take it from the same number of houses

solution (for example, blocking access to a file for others

processes).

2. Chitannya / recording. Call the exchange from files you can organize

deyakim blocks of tribute. Block of tribute, with yakim to see

exchange, do not have a subjective day. From one side, for be-like

calculating systems and views of blocks in danikh, yak

the most effective for exchange, so that the software

Apparatus size from the side of the

a real exchange can change quite a bit

programmer. In the functions of reading / writing down, call the figurine size

the block of money for exchange and the number of blocks of money,

you need to read and write down. From the vibrating size to the block

the effectiveness of real exchanges can be found, because

well, it is permissible for a deyakoi machine by the size of an effective

block of danikh є 256Kb, and you want to exchange information

128Kb

logical blocks for 128Kb. Douzhe imovirno, how to replace that,

in one exchange, read a block from 256Kb, and convert two

once to one block, and then read one half of the chat, and then

іnshu. Here є elements of ineffectiveness, I want a stench

zgladzhuvatisya "smart" operating system, but if you won’t

zgladzhuє, then it’s your fault.

3. Keruvannya file exponent. Practically for skin visibility

the file will be linked to the understanding of the file indicator. Tsey show,

for the analogy with the register of the team leader, at the skin moment an hour

I will step on to the address behind the file,

you can change the exchange. Pislya obminu with a cim block indicator

be transferred to the position through the block. For organizing robots

file is required in a keruvati cim show. Є

function of keruvannya file indicator, as permissive

pretty much (in the range of available) move the indicator by

file. Showman є by a wicked, accessible program,

yaka is tied to the function of displaying a file

zminnu).

4. Close the file. Qia operation can be done in two houses

vm_st file. 2) Attach the file.

After closing the file, all the links are attached to it, and

the deyakiy kanonichne camp.

4. Zakhist Danikh. Bagato strategic decisions are repeated yak on

hardware equipment, or if it does not have an operating system. Yaksho mi zgadaєmo

multiprogram mode, then one z necessary minds yogo іsnuvannya

є bezbechennya zahistu (memory that danih). I can see the file

system, it’s like that, like an operating system, you can

odnokoristuvatskoy. Whoever has problems with the hijacker are not dumb,

to that, lyudin, as a practicality with a central operating system, є

Gentlemen of our files. Apply single-handler systems - MS-DOS abo

Windows 95. You can lock the machine and protect all the files

koristuvach_v, like spaced out on disk, to that in cih systems

to take away the unworthy. Rozrahovana on a bagato koristuvachіv system will secure correct

to the robot bagatokh koristuvachiv. MS-DOS can also be used for

multiprogramming, ale vin doesn’t finish the correct

one process can lead to overwriting the operating system and

process. Also in the operating system Windows 95 can be very useful

koristuvachiv, the robot's ale is not correct

the system will not take care of all the rights of the owner. Otzhe, rozrahovana on a bagato koristuvachiv

the system can secure the information about the unauthorized

access. For the sake of the problem, the problem is tied not only with the file

system. In reality, the operating system will be secured for all

areas: files, processes, resources,

let’s neglect the name of the koristuvach. Here I pay your respects to

It is a fact that the point is critical for files.

The main characteristics of file systems.

The file system naturally includes all these authorities, such as

bully pererakhovanі for files, ale dodashche deyakі. Tsi power

tied with the structural organization of the file system.

Let's see the space of the VZP, and it's clear, like

you can organize the distribution of files at the border of the wide space.

1. One-way organization of files without interruption by segments. Termin

"odnor_vneva" means that the system will secure the robot with files.

uniquely named. A deyak is seen at the border of the VZP

the region of zberigannya danih, yak called the catalog. Catalog maє

I will step on the structure:

| im'ya | cob block | kintseviy block |

"Pochatkovy block" refer to the deyaku vіdnosnu address

the open space of the VZP, for which the file is to be repaired from the given names. "Kintseviy

block "start block given to the file... File display function

to be made up to date in the catalog and in the file and

kint (really, you can borrow it for less, less than a misce, for that

said more). Tsya diya is even simpler, before the catalog can be taken

at the memory of the operating system, and by themselves changing the number of exchanges.

As soon as there is a new file, it will be recorded on a new file.

Similar to the catalog of names, you can also use a table of large spaces

(Fragments).

Reading / writing to read mayzhe without additional exchanges, oskilki when

The range of data distribution is acceptable. Read more

according to the whole block structure and information

it is not necessary, it is necessary to exchange it more quickly.

If it is necessary to write down to such a file, dodatkov

Information, but there is no room for a digital file? In the whole vipad

the system can be fitted in place. First of all, just say it, it's dumb miscy and vi

guilty of doing something like yourself, for example, start a process like

transfer the file to the last message and provide the required information. Tsey

postponed - function to complete the road. Another possibility - in exchange

will be informed. Tse means that the hour of displaying the file is needed, but it’s too early

reserve dodatkove misce; when the file system is changed

the size of the vilny buffer, and if it is not enough, then the sound is vilne mice there, de

the file is resized.

Otzhe, bachimo, so the organization is simple, when exchanges are effective, al

there is a lack of space for the file to fix the inefficiency. Before that

Well, with trivial robots such file systems on the disk, those

those that were trapped in us with the operational memory - fragmentation. Tobto

the situation, if there are some fragments, even in the middle of them there is no such thing, kudi

You can build a file. Fighting from fragmentation for such organization

the file system is a periodic compression, if a new one is started,

important and important for the file system, processes such as

print all files one to one.

Such organization can be convenient for one-porous

file system, so with a great number of koristuvachiv even

fragmentation will be seen quickly, and the continuous launch of the compression is death for

systems. On the other hand, the system is simple and not to be

overhead vitrat.

2. A file system with block-based organization of files. VZU space

divided into blocks (those blocks, which are effective for exchange). Have

file system and this type of information is displayed in the same way

information process in the operational memory from the side

organizing. In a zagalny vipad with skin im'y the file of dressings, dial numbers

I will add blocks, in which the data is located in the file. And the numbers

the number of blocks may be in order, so that the blocks can be disassembled

I will arrange everything in a pre-order. For such organization it is not

fragmentation, if you want to add multiples to the block (if you want to use the file

one byte from the block, the whole block will be used). Otzhe, nі

problems of compression, and the system can be

insured on a large number of people in the organization.

In a wide range of skin file of dressings set of attributes: im'ya file im'ya

koristuvacha, for which access to the file is seen. Such organization

allowing the uniqueness of the name to be uniquely

vipad. Such systems require uniqueness and lack of middle files

one koristuvach.

The organization of such files can be done through the catalog. Directory structure

maybe booty taka. Catalog to revenge rows; skin i-th row

display i to that block of the file system. To take revenge on a whole row

Information about those who will take advantage of the block. Yaksho vin

occupation, then in a row to enter the іm'ya file (for example, on the other), іm'ya

koristuvacha, and may be provided with additional information.

For an hour, the system can be changed differently. For when you see

file, the system probes through the entire directory that will be a table of visibility

logical blocks in the file, їх distribution on disk Abo for skin exchange

there is a message from the center of communication.

Such organization of the file system є one-way within the

one koristuvach, so that all files are tied in a group of accessories until

like koristuvachev.

3. Intraarchical file system. File system files

prompted the structure to be called a tree. At the roots of the tree

This is the name of the root of the file system. Yaksho vuzol tree

є sheet, the whole file, which can be avenge of the Dani koristuvach,

but it is a file-directory. Vuzli tree from leaf є

files-directories. Menus in such an archive file system can

see in the new way. The first type is to name the file

the closest directory, to be able to browse files, such as є

The closest thing to the F0 directory is the F1 file, which is also

directory, that file F2. For a successful menu in such a system on one

rівні cannot be repeated name. From the side, scraps of all files

tied for the help of a tree, we can talk about so called outside of me

file, which can be stored from all files, which can be stored from

the root of the file system to a specific file. Outside the F3 file there will be

start like this: / F0 / F1 / F3. This kind of organization is good Tim, oh won

allows you to do something like a short file (as a system

rely on respect, which is true in this catalosis),

file. Change the names of the files to the path, and in any tree from the root to

be it a university іsnu diny shlyakh, otzhe, tsim see

the problem of unification of the name. The first time such a pidhid buv vikoristaniy y

operating system Multix, which was distributed at the University of Berkeley

for example 60s. The most beautiful solution has become a year for

buggy operating systems. It is a good idea for the center of the skin, for the skin files

You can bind attributes that are bound with access rights. Rights

I can access my mother's files as well as directories.

The structure of the whole system is good for organizing the insurance on a large number of robots,

for the analysis of the daily problems and changes, and such a system could be even better

grow up.

4. Personality and data acquisition in the operating system. Tsey nuance,

It is easy to understand and foldable at a time. Simple - to that

say about new, literally a few phrases, but folding, more

problems, about which you can talk dovgo.

Personality - the power of the operating system and identification

of a specific corystuvach and obviously accept that

dii, zokrema schodo danikh.

As soon as you love the MS-DOS operating system,

then there was not a buzz of the understanding of the koristuvach with the inheritance,

won odnokoristuvatska.

Another level of operating systems is the price of operating systems, such as

allow restructuring of koristuvachіv, or all koristuvachі

like a single set of deyaky sub'єktіv and tied each other in one way.

The application of such operating systems can be used for operations

IBM systems for mainframes-computers. For example, the lecturer does not know, hto

from which hearsay to which group to lay, or all, who sit in front of him,

Koristuvachi yogo course. It's good, it's bad. I'll see the rumor

course of lectures - tse good, ale for the lecturer

it’s nasty, so in one day, I don’t wake up to the experience of all. Youmu treba

There will be all the listeners as if they were willing, but not as if they were.

Apparently, for such a one-dimensional person, all

those functions, about which you were told (zokrema zahist), ale taka

organization of koristuvachiv transferring the approval of groups of koristuvachiv.

And for me it’s handy, let’s say, on our faculty server my

the laboratory is seen, and within the framework of the laboratory it is possible to

give one one access rights to files too.

Apparently, similar to file systems, it is

organization of koristuvachiv. Tobto mi maєmo understand "all koristuvachi"

that understanding "group of koristuvachiv". The group has real users.

Such an organizational organization of the persona

moments. When restoring someone who is koristuvach, you need a copy

attach yogo to yakois group - tse mozhe buti laboratory

the head of the group. Oskіlki koristuvachі ob'єdnanі in a group, then come

Possibility of access rights to resources of koristuvachiv. Tobto

koristuvach can, for example, declare that all resources are available for

all koristuvachiv groups. Such a scheme can be used for bagator_vnevoyu (group

to be divided into groups, etc.) with a clear distribution of rights that

possibilities. Infected operating systems, which have the right

access can be started not only with such an hierarchical structure, but with

they can be foldable, so that access rights can be added, and

ієrarchіyu.

Lecture No. 7

3. Operating system UNIX.

We switch to the installation of the operating system UNIX, some bugs

solution to be used in operating systems, we will

to look from the butt of the central operating system.

In the mid-60s, at Bell Laboratories, AT&T carried out

pre-release and distribution of one of the first operating systems at the current

її rosumіnnі - Multix operating system. Qia operating system

the power of the operating system is small for an hour,

insured for a wide range of systems, as well as in the whole system

basic solutions for organizing file systems, zokrem, bul

proponed to the tree-like file system. View of the shop

in a dozen hours the ear of the UNIX system arrived. One s

The history of the development of the network of systems to keep track of,

the PDP-7 computer is even more low-priced software security and is required

the machine, the yaka allowed the organizovuvati to be comfortable for the robot of the koristuvach,

zokrema processing of text information. Vidoma group of people - tse

Ken Thompson and Dennis Ritchie, got busy with the development of a new operative

systems. The greatest version of the history of history is to talk about those who are busy with the stench

realizing the actions of the grids and those that you can use, as the bullets are available,

They turned out not to be handy - just the stench appeared to be played with the central machine. As a result

Windows operating system UNIX.

Especially the system of systems

the program, yaka bula is written from vikorystannya movi, vidminnoi vid

machine movi (assembler). For the purpose of writing the system

software security, zokrem, operating system and UNIX, also

robots were carried out, which were distributed from the BCPL Movies. Z new bouv of claims

mov B, yaka operated with machine words. Dalі abstraction machine

sliv - BN, і nareshty mova Сі. Since 1983, the UNIX operating system (її

first version) the bule was rewritten to MOV Сі, і it was, it's close

90% of the operating system and bulo are written by my viskogo rivnya, not

lay down from the architecture of the machine, and 10% of the whole system is written in

assembler. At ten times the most critical ones were gone in an hour

parts of the operating system

Otzhe, the first important and revolutionary result bulo vikoristannya

movi viskogo pivnya Tsey fact wiklikav negotiated, no more

viriv, so it can be a little bit more

rіvnya assocіyuvsya because of the great ineffectiveness. Mova Sі Bula

constructions in such a rank, allowing, from one side, to write

complete effective programs, from the side, translate it into

effective code.

The first power is movi Sі, as it pіdvischuvala її efficiency, - tse

robot from showcases. The other power of the Pole is that when

Programming on assemblers is often viciously biased.

For example, if the result of the calculation is viraz є

not only of the written value, but of the industrial value,

which can be recorded along the way for a fake victorian. Tsi

opportunities have become available in the Movies Ci, so you can understand

move Sі nabagato shirshe, nіzh near quiet moves, like boules in obscurity

hour. Zokrem, the operation was assigned to the deputy operator.

privlasnennya, scho allowed the program to have a fatal effect. Tsi

power that gave rise to the "tenacity" of the mov,

system components and the ability to optimally translate the code of

Z professional (canonical) point of view, mova Ci - zhakhliv

mova. The main vimoy, yak to be presented at home

program, є safeguarding the safety of the program.

Make sure that you are guilty of the

program, and in advance to such

offensive: strict control of types (it is not possible, for example,

I do not change the type of speech before the cym

one of them to type іnshy). Mova Sі maє the power of reimagining

types for promotions. Іnsha krimіnalna rіch - tse securing control over

access to the memory of programs (so that in the middle of the memory you can

If the number is not, then we can’t interpret it.)

The ability of an uncontrolled victorian qih to give a value

vkazivniki. Moreover, through the indicator you can "cheat" the function

inconsistencies and inconsistencies of actual parameters in formal parameters

etc. The third power is control over the interaction of modules. Bagato

pardon is in that kind of fall, since the function has declared one set

formal parameters, and the adjustment to it must be followed

(Moreover, the evidence can be either for a number of parameters or for types). Have

My Ci can always fool the program - replace the formal parameter

one type of date parameter of the other type, and the replacement of ten parameters of transfer

one. Tse to bring to the mercy.

The axis is three positions, which are not happy with the Vimogam

safe. However, it will show that the most tenacious will appear

filthy (for a look) mov.

Otzhe, 1973 rik - rik appear written by my Sі operatsіynoї

UNIX systems. What are the main powers of the small system? Perche

Yakness is the concept of files. The main object, yakim operaє

operating system є file. File from the point of view of the operational

UNIX systems - the best pristine. File - tse directory, which is

to take revenge on information about files, to take revenge on new ones. I was so far away, on

what can be pratsyuvati.

Another power is a special structure of the operating system. On vidminu

from the frontal operating systems, for which the skin command is "sewn up"

internal operating systems, tobto. її is not possible bulo yak-something modifіkuvati,

in UNIX-i command problems are even more elegant. First, UNIX

declare the standard interface for transmission of parameters to the call to the middle

process. In a different way, all commands are implemented as files. Tse meansє,

you can easily add new commands to the system, as well as clean up

modif_kuvati їх. So, the UNIX system can be easily developed and developed.

Rospochnemo discernment of the specific powers of the operating system.

File system. Organizing files. Robot with files.

The UNIX file system is secured for a lot of

file system Її structures were painted on the last lecture. Won

represented by a tree, the root of a є, so titles, koreneviy

catalog. Vuzla, viewed from the leaves of a tree, є catalogs. Leaves

There can be either files or files (in the traditional way), or empty directories.

The system is assigned to an understand and to a file - tse im'ya, yake associyovane z

a set of tributes at the border of the directory, where the file is to be found. Krim

in addition, є an understanding of the main name - a unique way from the root of the file

system to the file. Allowed zbig imen files

at the latest catalogs.

As a result, the file system is not tree-like. Є

the power of the destruction of the State Archive for the rakhunok of the cattle, which allows the association

little name (s) from the file itself, - tse, so

ієrarchіchna and tree-like.

In the operating system of UNIX, there is a trio of hierarchies

koristuvachіv (usі corystuvachі divided into groups), the structure of which in

At the zagalny vipadku, the bulo is seen in the foreground lectures. At the zv'yazy z tsim kozhen

The file system file has two attributes. The first attribute is tse, so

ranks vlasnik file. Tsey attribute of dressings with one specific

koristuvach, which є vlasnik file. Vllassnik file can

articles for the changes, how to open the file, as well as the є command, yak

Allowing the file owner to minify. Another attribute is a tse attribute, dressings z

zakist access to the file (the report will say more about it).

Access to the skin file is regulated by three categories. Persha

You can connect everything from the file to everything you need. Other category -

the rights of the group, to which the owner of the file should be assigned (see the rights

a vignette of a general group. For tsimi three categories

three days are regulated - reading from a file, writing from a file and a vikonannya

file. The skin file is assigned, which can be categorized as

process.

Robot with files

The structure of the file system and the disk is understandable. For be-like

the numbered system and the understanding of the system memory

attachment (SVZP). SVZU - tse pristіy, before what kind of access

Apparatus zavanazhuvach machine with the launch of the operational system Mayzhe

whether the machine has a range of addressable memory space,

distribution at the so-called post-storage zapam'yatovoy attachment (ROM). Have

ROM grows small program (hardware zavanazhuvach), yak when

the inclusion of a hardware rewiring of the machine,

to the SVZU unit, which is distributed in the operational memory and the transfer of control to

The addresses are fixed, which should be provided for the number of danims. Get involved, well tsey

Licheni block tribute є, so we call it, we will add it to the program.

Slide it means that the equipment cannot be stored away from the operation

The system, and the software lock is a component of the operating system.

I already know that the data required for the launch of the operational

The be-yak_y system_ has taken the space of the CDW for deyak_

areas given, are called blocks. Size of the logical block

є fixed OS attribute. In the operations

UNIX system size the block to a specific parameter that can

Change the deposits from the system version. We will be for singing

kazati, scho logical block VZP dorіvnyuє 512 bytes.

Imagine the address space of the SVZU at the viewer

block Zero block SVZU - tse block of cob entangling, or a block,

as there is a program zavantazhuvach. Distribution of the block in the zero

Blots of SVZU are started separately, that is why they are installed separately.

turn itself until the zero block. The last component of the file

systems, how to lay down from the apparatus.

The upstream block is the superblock of the file system. Win revenge

operational information about the line mill of the operating system, as well as

data about the parameters of the file system adjustment. Zokrema, superblock

revenge information about the number of so-called index descriptors in

file system. The superblock also reveals information about the number of blocks,

warehouse file system, as well as information about storage blocks

files, about the index descriptors, and about the data,

to characterize the hour, date of modification and special parameters.

| Block | Superblo | Region | Blocks | Region |

| pochatkovoї | to | index | files | saving |

| zavantazhennya | file | descriptor | | |

| | systems | iv | | |

The superblock is followed by an area (space) of index descriptors.

The index descriptor is a special structure of the given file system,

as to be put in a mutually unambiguous relation to the skin file.

The size of the space of index descriptors is set by the parameter

generations of file systems for a number of index descriptors, such as

indicated at the superblock. Skin index descriptor revenge taku

Information:

2. The field will be retrieved.

4. Dovzhin file in bytes.

The upcoming space of the file system is the whole blocks of files. Tse

space on the system attachment, in which all information is distributed,

how to save from files and about files that were not placed in the front blocks

file system

Remaining the area of ​​tribute in the old systems is realized in a rational way, ale

behind the blocks of the file system - the whole area of ​​saving.

This is the conceptual structure of the file system. Now it's clear

Superblock. The greatest interest in the superblots

fields: information fields about file blocks and file indexes

descriptors. The UNIX file systems have two chinniks added.

The first bureaucrat - tse those, that the file system was broken at that hour,

If the Winchester obsyag is 5-10MB, it is already great. Middle structures

the space of the outbuilding. Another factor is the power of the file system.

to optimize access. Optimal access criterion - number of exchanges

file systems from external attachments, like won viroblya

baked goods

List (array) of file blocks in the warehouse to be stored in fifty

elements and loans 100 bytes. At the buffer, you can store for fifty

The elements of the recorded numbers of the blocks in the space of the memory blocks. Tsi

numbers recorded from another element until forty-ninth. The first element

Array to revenge the number of the last one I will write in the whole array. Zero element

the whole list is continued, etc.

How many processes are required for expanding the size of a file

additional valid block, then the system is behind the client Block number (NB)

vibiraє element of array (copy to the superblock of the presence in

operational memory, that may be the case for all such systems does not

need to feed up to SVZU) and the unit should be

the file for expansion (when the NB indicator is displayed). Yaksho

to view the file quickly, or if you see the whole file, then

rooms, scho vivilsya, enroll in the array of vilny blocks, at a

You can also see a correction of the NB speaker.

Oskilki rozmіr array dorіvnyuє to fifty elements, then maybe dvі

Critical Situations Persha - if there are no new blocks

to be given a favor to this number from the whole array, some of the winners have already been rewarded. In tsyom

vipad with the file system, one valid block is vibrated (with a

to be seen from the list of valid blocks) and storage of an array of valid blocks

copied from the whole block. If the value of the NB indicator is reset to zero, and in

a zero element will be written to the array with the number of the block, which was selected for

copy to our new array. Results with permanent sound

blocks, there will be a list, in which there will be different numbers of absolutely all

file system blocks.

Another is a critical situation - if you need to reject a valid block, please

vm_stu array vycherpavsya. The system of dіє is like this: yaksho

a zero element to the list is given to zero, which means that everything has been drawn

the space of the file system, and it will appear at some time. Yaksho vin not

return to zero, instead of to the address of the continuation array, i

operating system for a separate unit and for space

continuation on the site to the array in the superblots.

Another array, which is located in the superblots, is the tse array, which is stored

from a hundred elements and to replace the numbers of the new index descriptors.

Robot from the cym array is easy to work with. Poki scho є misce in tsomu

array, then with valid index descriptors, valid indexes

descriptor write to vilny miscya array. Yaksho array of memorials

again, write down the array of leaning back. Yaksho, navpaki, vmist

the array was drawn, then the process starts, which

view the area of ​​index descriptors and remember

array with new values. The situation is possible, if you need to open the file, tobto.

a new index descriptor is required, and in an array of many

process launches also know the valid index descriptors. Tse

another situation, if the system is prompted to declare,

(Persha - if some blocks of the file system end).

Lecture number 8

Index descriptors. Index descriptor

blocks, go to disk. The size of the region and index descriptors on the basis of

parameter (which is assigned to the hour of the system installation), but the initial

number of index descriptors for a specific file system.

Regional Development

descriptor.

The index descriptor is a UNIX object, which can be used instead of

unambiguously recognizable to a file instead of a

file є a special file, associations from external attachments. Have

The index descriptor contains the following fields:

1. The field indicating the type of the file (chi ni directory).

2. The field will be retrieved.

3. Number of references to the whole index descriptor from the previous

directories in the file system (the situation has a damaged file tree

systems). If the value of the field is zero, then it will be

tsey index descriptor є valid.

4. Dovzhin file in bytes.

5. Statistics: fields that characterize the date and hour of the day of the day.

6. The addressing field for file blocks.

I respect those who are in the index descriptor in the dumb file,

I want the object to characterize the file. Let's wonder yak

the addressing of the blocks is organized, in which they are located in the place of the file.

The address field has the number of the first ten file blocks. Yaksho

the file is small, then all the information about the distribution of these blocks is located in

index descriptor. I will change the file ten blocks, I will start

practical list structure. The eleventh element of the addressing field

place a number to a block with the space of file blocks, in which there are 128

file on blocks.

As the file is larger, then it will be victorious two times.

element of address. Win revenge the number to the block, in which there is 128

records about block numbers, with 128 numbers in file blocks

systems, so that here it is victorious to subtract indirectness. Yaksho file shche

more, then thirteen elements will be victorious and will be consumed

Indirectness (similarly to sublinearity, but one more rіven is needed).

Boundary size for a file (with size block 512) for a file (128 + 1282 +

1283) * 512 bytes = 1GB + 8MB + 64Kb> 1GB.

We have been homely with you, stretching out our course, we are going to kill

respect for the inconsistency of the news and for the bad news. Persha

the problem is that the file system is not small in the superblock array

blocks, then it would be the rank of shukati

blocks, і tsya of the robot was bored, і the file system fell on

іdeynomu іvnі. Similarly to the list of wild index descriptors,

I want a little shit here buv bi simpler, lower for vilny blocks, prote,

here є elements of optimization. Indirect addressing of blocks

files allowing for build-up overhead vitrati from reading blocks of files

proportionally to the size of the file. Tobto, if the file is small, then overhead

Vitrat is dumb, so when you open a file in the operative memory, it goes off

copy of the index descriptor to the file, that without additional bits to CDW

you can go from ten blocks to a file at once. It is necessary

pratsyuvati with blocks, spaced at the first level of the indirect address,

there is one additional exchange, or access is possible

up to 128 blocks. Analogous mirkuvannya and for blocks of another and third

order. Building b, nasty are those who, when exchanging with a great file, are brought

zd_ysnuvati bezl_ch additional exchanges, the UNIX protector system is tricky -

vona vicoristovuє gliboku echelonovanu buffering of exchanges іf VZP. Tobto

if I can’t accept deyaki overhead vitrati on one ruble, then the stench

compensate for the best optimization of the interaction of the system with

zvnishnyoi memory.

File Blocks The size of the space for file blocks is unambiguous

rank for the information rakhunok in the superblots.

Process protection area. The desired area is displayed behind the blocks

files, Ale Vona can be placed in a file system

for a good mix of CDWs. Tse to lay down a specific implementation

systems. By day, tsya region є cinnamon region, to which

to see the processes, as well as the area to be victorious for

to optimize the launch of processes, so that most often the victorious ones go to the vicarious ones,

the so-called, t-bit file (the report will be stated later).

So, we have seen the structure of the file system and її

organizing on a systemic arrangement. Like a system design,

the structure of the file system that is linked to it by the algorithms of the robot

pads, for an hour, robots with them, the overhead vitrati did not go beyond the boundaries

smart. The UNIX file system with real robots is highly optimal

file system Windows NT (compare the dates of the distribution !!!), for the simplicity

that optimizatsiyi, like being trained on the skin.

Catalogs

You have been told that one of the powers of the UNIX operating system

and those that all information is distributed in files, tobto. dumb

special tables, like the operating system,

the table is quiet, as long as it works, it still functions in

space of operational memory. Directory, at a glance of the file system,

The whole file, in a different way, about those files,

catalog.

Catalosis A has files B, C and D, unaffected by those

files B and C can be either files or directories, and

file D є directory.

The catalog is stored with elements, where there are two fields. Perche field -

number of the index descriptor, another field - the target file, yake

associated with a cim index descriptor. Index numbers

Descriptors (in the vastness of index descriptors) are repaired from one.

The first index descriptor is the index descriptor of the directory. Have a fancy vipadku

at the catalysis there can be a recording, which can be applied to one and the same index

descriptor, but at the catalosis it is hard to know the records, the same name may be missing.

I am in the boundaries of the directory є unique, but in the place of the file you can

the association is a great number of names. Tom є deyaka

the ambiguity of the visitor to the file in the operating system UNIX.

The file is not just named by a set of tributes: vin maє

index descriptor and may be the name of the name (tobto the name is secondary

component).

When the directory is opened, two entries are created in the new directory:

special file with im'yam "." (full stop)

the descriptor of the directory itself, that file ".." (two dots),

associate the index descriptor (ID) of the Batkiv catalog For our

butt catalog A maє, for example, VD z number 7, and catalog D maє VD z

number 5. File F maє VD No. 10, file G maє VD No. 101. I have a file vipadku-

catalog D matime like this vm_st:

| Ім'я | №ІД |

| "." | 5 | The first record is to record on yourself. |

| ".." | 7 | Another entry is for dad (catalog A). |

| | | catalosis. |

| "G" | 101 | The axis will fit the D catalog.

Attachment to the file-directory of the original files of koristuvach polyaga

instead of the field to the file type in the VD. For the root directory of the field dad will

take advantage of the new one himself.

Now it is schematically discernible, as it is possible to vikoristovuvaty on the name

that directory structure. In systems, at the skin moment an hour of robots

koristuvach, the current catalog is assigned, so that the catalog and all the way

a root tied with a tsim catalog, which for

All names of files cannot be repaired because of the "/" symbol. Yaksho current catalog D,

then you can just talk about files F and G, but if you need file B,

then it is necessary to choose a special file ".."

given vipadku, construction ".. / B". We decided on the file ".." - tse

means that it is necessary to read the VD dad and according to the new way in the place

catalog A. Poten by file-catalosis A need vibrate row with im'yam B and

visually to the ID file, and then to expand the display to the file. The whole operation

to finish a labor worker, a prosthesis will look at those who do not see files often,

doesn’t know how to use robotic systems.

We said that we could help ourselves together.

kіlka іmen, tobto. instantly you can view files with one and the same

VD. The problem is how the robot can synchronize with a file in

at the time of the opening by different processes or by different names. UNIX has a

you can do it correctly (it’s easy to see it for a while).

Special attachment files

We already know two types of files: files-directories and work files,

of which data are collected. Є third type - attachment files. Qia

type is characterized by a type, meaning in VD. Вміст у files

attachment is nemaє, and є deprive VD that im'ya. The VD will include information about those

What type of attachment will be attached to the zim file: byte-based

pristіy abo blocking pristіy. Byte-oriented

pristіy - tse pristіy, exchange with yakim, one by one

byte (for example, keyboard). Block-arrangement of pristіy - tse

prist_y, with yakim exchange can be done in blocks.

Also є the field, which is the name of the number of the driver, tied to the

annex (in one annex there may be a number of drivers, but not

navpaki). The correct field is the number of the driver tables

type of annexes. In systems є two tables: for block-

That for byte-based attachments. Also in the VD there is a deyak

digital parameter, which can be passed to the driver

I will clarify the information about the robot.

Organizational exchange of data from files

Visually significant with a sprinkle of low-root introductions / vivod

systems. The UNIX file systems have special actions

functions, which are called systemic links. System wiklicks

go to the operating system, so that

functions that determine the actions of the operating system. Realization

system and library functions (for example, mathematical)

see. As a bibliotech function will be added to the process,

if you want to use the library, then all the events are great

will be vikonuvatisya in the middle of the process, and the system

transfer of control of the operating system to the vicon

diya. At UNIX-e for the protection of low-root I / O, tobto.

introduction / vivod, which is implemented with the help of system wiklikiv, є

set of functions. The main axis of them:

1.open - Display of an explicit file. One of the parameters of the whole function

є row with іm'am file, and rotate in deyake number,

as a file descriptor. In the process of koristuvach,

as well as divers who associate with the process

(except for the code that danih, zrazumilo) deyaka service information,

zokrema table of file descriptors. Vaughn, yak and all tables in

UNIX system, position, tobto. descriptor number

I will write down the number in the tables. File descriptor (FD)

associated with the file and all the necessary attributes for the robot with it.

FD numbers are unique in the boundaries of one process. Є similar

function create - function to display a new file.

2.read / write - system wiklici read / write, parameters such

є FD number and attributes, which are not so important for

our look.

3.close - system wiklik of completion of the robot with the file, the parameter

which є FD number. Send the beast to the full function of the FD

will become valid, and the robot will complete the process from the file.

Axis deyakі systemnі wikliki, scho to preserve the introduction / vivedennya (before speech, stench

may not add the code to your programs). Details to wonder

independent. I have brutalized your respect, as a system wiklik, to that

that introduction / delivery can be made available through the introduction / delivery library. For

so many titles, file sharing and functions fopen, fread, that

etc. (3 prefix f). A lot of bibliotechny functions. The functions are self-sacrificing

to low-root functions in sob.

The organization of the exchange from the system point of view in the operations

UNIX systems. When organizing the exchange of the operating system, the system is

that data, associated with the operating system.

Table of index descriptors for all files. Persha table danikh

associations with the operating system - table of index descriptors

view files (TIDOF). Qia table to revenge records, skin

Reveal a copy of the index descriptor for skin infection in the system

file. Through a copy of the copy, access to the file blocks is provided. Kozhna

records in tables should also include a field that characterizes the number of

file systems, such as vikoristovuyt daniy descriptor (filer). Tobto yaksho

one and the same display file from one or two processes, recorded in TIDOF

there is only one, a little more skin-dodatkove, the file is full

lichilnik per unit.

File table File table (TF)

Lecture number 9

We said that the system can work with a built-in file in that

only in that case, when the process of restoring the freedom of pratsyuvati s

cim file. The fact of such a restoration is called a display file. At

to a file in between the process of a skin file to be displayed

(you can see the existing file, anyway) to be placed in

specificity to a unique integer number, as called file

descriptor (FD). At the border of the FD process, there is a numbering from 0 to k-1.

The value of k is the whole parameter of the adjustment of the operating system, which is the initial value,

Skіlki immediately from the critical files can be in the process. Here

then it means that we are talking about a number of files instantly

(as it is written in a UNIX book), protest, for good reason, k -

the maximum number of FDs, which can be associated with one

file, which is one and the same file at the interface to the process can be viewed two

once, and two FDs are established. What do you give me, I can see it

piznishe, ale tselkom correct. Send a message to the file of all operations of the exchange

go through file descriptor links

do not bother). Low parameters associated with the skin file descriptor

(There are a few words about them).

Let's wonder, how to organize the introduction / delivery, or rather the processing

low-root exchange from the point of view of the operating system. Infection will

it is said about logical scheme organization of the introduction / vivod, the scheme is real

It is built in a cheap way, but it is not so important for us.

Usi dans, with the operating system, can be divided into two

class. The first type of tribute is tribute, association with operational

system, tobto zagalnosystemnі danі. Until the tsikh danikh, TIDOF is introduced.

The size of the fixation tables and the start of a few seconds at once from the critical

FD. Kozhen record at the ts_y tables_ to take revenge on the deyak_informats_yu, middle

what kind of tsikavitime we are attacking:

1) Copy of the VD of the open file. For any kind of file, VD, like

characterizing instead of a file, copied and distributed in

TIDOF. Writing all the manipulations with the file (for example, a

the address file) are viewed from the copy of the VD, and not from the VD itself on the disk.

TIDOF displaces at the operational memory, tobto. access to information in

she is good at it.

2) The checker for the given moment of the files, linked from the data of the VD. Tse

means, for be-what kind of display in the file linked from

For the data of the ID, the system is working with a single copy of the ID.

Now let's move on to the so-called file tables (TF). Files table

store from fixed number of records. Kozhen recording TF

will be displayed to the current system file ((more precisely FD)). With tsom in

The importance of the difference is important є the difference is also unambiguous.

That vypadok, if not є in a mutually unambiguous manner, mi

Visible below. Kozhen recording TF to avenge proponents of reading / recording by

file. Tse means

for two in one process, then with the skin indications of dressings, one

the stench of one kind of one does not lie

vipadkiv). Kozhen record TF to revenge so titles index

falloff is a whole number.

The price of the operating system, tobto. give, describe

the system has problems with zagalom.

With the skin process, the so-called table of open files is tied

(Pacific Fleet). I will write down the number in the table є FD number. Kozhen row of tsyogo

Information about showcases, tied with FD, hiba rosirvan. One

parties, file descriptors - tse dan, scho є an attribute to the process,

from the side, the indicator is the tse dan, which is an attribute of the operational

systems. It’s not logical, it’s not logical, and it’s clear at once, who

illogicality to manifest itself. The conceptual

food, tied from the form to the process. Operating system UNIX

we have a fork () function. Tse system wiklik. In case of malignant systemic

wikliku in the system to see a deyaka diya, yaka for a great

you can be blind, - to copy the process,

to which the function was created, tobto. the process is happening. For whom

It’s necessary, I’ll say three things more.

Formation of the process-dvіynika maє takі power. Perche

power: process-syn, which will be formed by the beast to function

fork (), there are all those files, like the bullets are opened in the process of the dad. Friend -

the system allows you to do something with power, identifying, de

process-dad, and de process-sin, I want the stink in the gallant vipad

however.

Supposedly, є process number 1, і it is associated with a table with

file # 1. A file with a Name, and a file for the whole process

assignments at the type of file descriptor I.

according to the row of the Pacific Fleet, there will be a record, which can be sent to the TF. Have TF

it is assigned as an attribute, linked from the file, and also є

showcase reading / writing, tobto. that showman, behind yakim mi pratsyuєmo,

Obmіnyuchis information іf file. Entries in TF may be posilannya on TIDOF,

Yakoyu є copy of ID, similar to the file with names Name.

Supposedly, the file with Name.

The system put youmu at the type of file descriptor J.T.

displaying the J-th row of the Pacific Fleet in the first process. At the end of the record

display file Name. First step of the index of the decay rate for both types

to get one. All records will have their own, tied with cymbals,

showers read / write. File descriptors I and J independent

each other, tobto. pіd hour of reading / writing through file descriptor I,

the file descriptor indicator J does not change. Tsey will write down

on the same index descriptor from TIDOF, and the value of the pilot will be

one two.

Supposedly, the process # 1 is processed before the fork () function,

copied the process

from fork (), and another process will be associated with Pacific Fleet No. 2. So it will be

display the file Name for ID I and ID J.

see the files at the recessions from the daddy,

Pacific Fleet will be displayed not on new TF records, but on those

Daddy got the message from FD. Do cich processes show you reading

the records will be the same, tobto. if you put the showcaster in one process,

then it is automatically overridden for the process. Tsey vipadok, yak

once that, if there is no mutually unambiguous similarity between the rows of TF and

rows of Pacific Fleet. When the chicks are bred, the clerk will increase by two. I,

for example, from the VD, for the address block of the blocks, there is access to

block files Taka information organization obmin means, scho obmin

from in place of the skin file, it is centralized, tobto. by the way

with a permit, all requests for exchange should be sent through one single entry,

The files that were linked from the VD cym were not readable from the system. There are many

koliziy, if in an hour the rogue should be repaired by the viconians, or

nevikonanih exchanges tied with one descriptor.

For any formulation of a new process, the aprіorі system will

null, pasting and other files descriptors from the TOF, linking from

with the value files. Zero FD of dressings from the system file introduced, from

he will be called upon to associate the name of the claviaturia. First FD - tse

standard file vivodu, link from it to the associations of the monitor screen. The other

FD - the whole standard file for diagnostics diagnostics, with it also

Call for monitors' screen associations.

Easy to read for the butt of types when turned to quiet

system wiklicks.

Twisted before the fork () function. Yak vidomo, with the beefed up to the full function

the system is a copy of the outgoing process. At the same time, the PAF duplication system

one process in the Pacific Fleet, the process-decline, as well as one-by-one

index of decay for rows of TFs, associated with visible files

out-of-order process, as well as overcritical files

data from VD, in TIDOF.

Turning to the open () function. When finished to the full function, view

onset:

1. For common name to start a catalog

2. The VD number is indicated. There is a joke behind the VD number.

tables TIDOF.

3. If the record is given by the number indicated, the physical number

a single row TIDOF that can be switched up to croc 5.

4. If the row is not visible, the form is displayed

a new row, showing the new VD and fixing її

5. Coriguєmo lichilnik posilan (strikers) on the TIDOF record. Number

Recordings in TIDOF to register before recording TF, as well as to TOF

until the programs turn the number of the TOF term, at yak

During operations, the introduction / implementation of systems is obvious.

Vzaєmodiya iz outbuildings. We already said that all attachments,

if you are serviced by the UNIX operating system, you can

classified into two types - byte-based attachments and block-

free annexes. Slid means, but one and the same pritіy

the system can be seen as a byte-based system, as a block

orієntovane (butt - operative memory). Vidpovidno, є

block-based and byte-based drivers. Past lectures

looked through special files, associations from external annexes, that

talked about those who є table of drivers in blocking attachments

This table of byte-based attachment drivers. Apparently, on ci

The main feature of organizing robots with blocking

annexes є the ability to buffer the exchange. The essence of the fieldє in

offensive. In the operational memory of the system, a pool of buffers is organized, de

skin buffer ma razmіr one block. Kozhen іf cich blocksіv can be used

associations with the driver of one of the physical blocking

attachments

It’s clear, how to visit the last day of the week

block iz annex numbered M.

1. In the middle of the buffers in the buffer pool, there is a sound of the given

block, tobto. when a buffer is detected, to avenge the N-th block of the M-th

I will add, fiksuєmo number of the tsy buffer. In a whole lot of vipad,

turning to a real physical annex does not appear, but

operation of reading information on submissions from information

from the known buffer. Passable croc 4.

2. Whenever the given buffer nears the distance, then the buffer pool

there is a message of the buffer for reading and changing the data

block. Yaksho є vilny buffer (really, tsya situation

only when the system is started), then the physical number is

Moving on to croc 3. If you didn't know the buffer, then we

vibraєmo buffer, until there is no beast

hour. Yakshcho in the buffer

violated to write information to the buffer, then it will be displayed

the real record of the spaced in the buffer block on the physical

pristіy. Go to the fiksuєmo number and also go to

3. Reading the N-th block I will attach to the knowledge

4. To reset the indicator to zero for an hour in the given buffer

increase on one unit in one of the buffers.

5. Transferred as the result of reading in the place of the given

You bachite, here is the optimization, tied to the minimization

I will arrange the real beasts to the physical. Tse to finish the cinnamon at

system robot. Record blocks follow a similar circuit. So

buffering at low-root injection / vivodi was organized by the rank.

Perevagi are obvious. Inadequate є those who have a system

є critical to unauthorized hacking, tobto.

the situation, if the system's buffers are not vivant, but are displayed on a stand-by

the application of the operating system program, which can lead to

go to the information.

Another shortcoming of the Pole is in the fact that for the buffering of the rosirvano

at times the fact of the beating is up to the system and behind the exchange and the real exchange. Tsey

not so many times appear at times, as in real physical exchange

be seen. Tobto. it is necessary, permissible, to write down the block, win

to write to the buffer, and it will be displayed from the system, so the exchange ends

Successfully, if the system actually records the block on the CDW, it’s impossible. At

At any given moment, the situation is tied to him, but you can write down

do not pass, admittedly, through the defects of the nose. Go through the situation, when

for the process was successful

(the process of trimming the message, everything is written down), but for the sake of the exchange

In this rank, the system is insured for a

Correct professional skills and exploitation. To fight with ymovirnistyu

waste information in case of abnormal situations, the system is sufficient

"reasonable", and is correct. Zokrem, in the system є singing parameter,

as soon as possible, as soon as possible,

through yakі zdіysnyuє to get rid of systemic tributes. Friend - є

the team, which can be available for koristuvachev, is the SYNC team. For a price

command zd_ysnyuєtsya skidannya tribute to disk. І tertє - system of ma

deyakoy overwhelming

typing, like updating information, or about secondary blocks, like

without going into the identity of the file, it will be recorded in

The file system is unrecognizable. You can have a try

I will analyze and update it by hand, if it’s worth it. Our

university is one of the first in the country to operate

the UNIX system, and at once you can tell about the problems of unreliable systems,

from a glance fatal information, buv.

This year we wrote a rosm about those that we have є system wikliks that

libraries of introduction / vivod. Another one, which is permissible

optimize the system for the robot, - the price of the standard input / output library,

tied to the stdio.h include file. The essence of the conceptual exchange is the same

itself, for organizing low-root input / output. Riznitsya in that

open () rotateє file descriptor number, fopen () rotateє

Shows the structure of the special type FILE. The other is the main

Tse library of functions. Bagato function service, yaki nadaq tsya

library, which can be realized in the boundaries of your address space. Have

Zokrem, such a functional service є one more level of buffering

introduction / delivery. The essence of yogo is that the resources can process

see a buffer, which is similar to the buffer pool

operating system that minimizes the beast of your process before

system wiklicks introduction / vivod. Zrozumіlo, scho tsya library for input / output

to implement for additional programs, like a vicorist system wiklici

introduction / delivery. Tse means that there is a sub-buffering factor, if

the price of inconsistency.

Subway buffering, mabut, rich cinnamon. Vaughn allow you to turn around

before reading, or I will write it down through the library functions with tributes at the pivblok

for a third block, and if it’s a part of it’s going to sleep, then the system itself is

buffering, collecting parts and replacing some animals to the system

vicliku viconuє lishe one beast. It's obvious. Invisible those who are

buffering to be organized between the address space of the process

all by inheritance (synchronization is destroyed with the exchange of

at a vipad, like a file through a library of processes,

In addition, in the skin process є its own buffer, which can

akumulyuvati tsi danii and zhodnoi odnosti, yak in

by us in the diagram, do not go). Tim is not mensch, standard

library introduction / vivodu є hand tool; won maє also koshty

blocking the buffering center.

Lecture №10

Past lectures, they picked up the coming moments, knitted from

organizing the function of the file system. Systemic organization

low-root exchange. Mi z'yasuvali, for the rakhunok of organizing donations,

the operating system UNIX can be reached with simple and "insight"

viral problems of possible conflicts in one and the same

the same file. Mi bachili, all of them display one and the same file (pid

file my mind is not just, but instead)

from a single copy of the VD. We were z'yasuvali with you, how much more visibility

files, linked to one VD, generate the power of practicality for the processes

with my own testimonials, I will read / write down by file, by vignette vipadkiv,

If the file is processed through the process, then tobto. file bulo otrimano

from the process-dad through the fork () function by the process-blue.

We were zyasuvali, that the system of add-ons, how to be serviced.

into two classes: block-based and byte-based. One and another

attachment can be done at once and byte-based, and block-

orієntovanim. It’s not possible to lay down yak from the outbuilding itself, so it’s obvious

Drivers - programs of keruyuchy cims to add. With the help of such

I will arrange є operative memory.

We have seen the principle of organizing low-root exchange

block-based annexes, and in the context of

by means of buffering, how to get stuck in UNIX OS, the essence of which

field in that, for the analogy with buffers, reading / writing from the operational

memory (hardware), the operating system of the software

take in, as you allow to minimize the number of animals to

I'll arrange a physical one. The whole mechanism is visibly displayed and developed for UNIX OS.

Then you will respect that buffering can be exchanged.

The first dodatkovy r_ven can be found for the one that prist_y

You can use your own hardware buffers, implemented for analogous buffers

operative memory.

We also talked about those who like low-root introduction / vivod,

with connected functions, which will prevent system calls (open, read, write

etc.)

library for input / output stdio.h

for organizing exchanges one more level of buffering (for optimizing

zvernen to systemic victories), which is associated with the process, tobto.

Buffering for loading resources in the process. Mi otsіnyuvali, well, good,

shitty. Obviously, buffering is quicker than the number of exchanges

we will have more invitations than

view exchange. However, those are rotten, for the buffering rakhunok decrease

the reliability of the system. For example, when unsupported for the system

Harchuvannya, all buffers consume information. The moment of brutality before the exchange is far away

real exchange and the possibility of not accepting the situation. Ale, unaffected by

tsi incomplete information, ado

Ridko even more.

I wrap up your respect, for some UNIX zaschazhuє zastroyeniya to VNZ.

The superblock is located in the operational memory, and in real life from information

superblocks are not loaded from the disk, but from the operative memory, I want it here

the problem itself is the problem of unsanctioned handling.

Open file, mi pratsyuєmo from VD. Mi z'yasuvali, the robot z VD

communicate through the robot with a copy, distributed in the software

tables in the operational memory. Tse means, shho mayzhe no overhead

vitrate, tied with small files, and overhead vitrati small when

robots with magnificent files. Walk like this, so that the whole infrastructure can be

I will receive the file system robot, pratsyu for opening the file system

advanced buffering.

File attributes

We talked about the organization of the coristuvac systems; won maє

the structure

Be-like koristuvach to lay down to the groupie. Up to the State Archives

koristuvach_v, assigned to the hierarchy of the filer and the rights of koristuvach_v.

The file is assigned to the file. Spatku vlasnik file є

koristuvach (or, more precisely, the process of koristuvach), which has opened the file. Attribute

The "file vlasnik" can be changed with the changeown command. Skin file maє

attributes to the zahist, tied with the ієrarkhієyu. Є the right to access

go to the file from the side of the vlasnik to the file. Tse rights to read, on

record, for a visit. At the skin file, krym rights, tied іf rіvnem

koristuvacha, є right, tied with a group. Tse is right for everyone

koristuvach_v group, to which to lay the master file, cr_m

yogo (tobto the rights of the master of that yogo group of rіznі). Third category

zakistu - all inshi. Tse ti rights, as may be usi koristuvachi

systems, krim vlasnik and її group. The system has a team

Change of access rights change mode.

Krim attributes in access, skin file can be marked,

zokrema, t. t-bit and s-bit, as it also becomes a deyako

command. We already know the structure of the file system;

The file can be used for a heavily fragmented viewer. Besides,

the file can be great, but when you see a great file, you get overhead

Vitrati, tied with access to distant file blocks. To that vіdkrittya

file is a trivial process. Optimize your performance,

The system has the ability to identify files with a t-bit. Pislya tsyogo

see the next step: at the time, when you click on the file,

values ​​t-bit, then for the first wiklik for a session of robotic systems and

copy the file to the save area. With cutaneous re-wiclik

file, a list of views to the catalog of the area of

if the file is there є, then the locked file will be viewed not from the VZP,

a z cієї galuzy. So there is only one road of minimizatsii zvernen to VNZ.

The possibility of establishing a t-bit is the prerogative of the system.

administrator, that system administrator he picks up the processes (i

apparently, files), which require a t-bit. Name it mean

those processes that happen most often (for example, for example, where

workshop, then t-bit maє sense means the compiler file).

S-bits are visible on top of trochas, slightly turning to new ones.

Є that is the problem. Try to keep the system in order, because all

koshty, all command (for the blame of deyaky vbudovani) in kintsevoy

rakhunku are files, like a master. Yakis iz

The number of commands can be converted to quiet system files. Vinikaє

the problem is tied to this, from one side,

unauthorized access to the file. From the side, command me to

potential rights of all categories. Yak bootie? Є Possibility to mention

deyaki files s-bit. Vlasnik file with s-bit to become unaware, ale

when starting a file, the owner of the process, by running the file,

Nadajatsya the right to access to the given file.

Supposedly, є file, how to visit from іm'yam file, і win pratsyuє yakim-

then the file file2, which contains the confidentiality information.

Supposedly, file is file2, which contains information about

all registered koristuvachiv i, zokrema, file can be changed

password for the system. If I run the file from my name, then I can

win two situations: for I can’t work with file2, for what є

oblikova information about koristuvachiv

reshti; for it is a fault of everybody, that is not a fault of anybody. In the whole vipad

pratsyu s-bit. The essence of yogo robots is in the offensive. Vlasnik

output file є coristuvach ROOT. Supposedly, the whole file wants

launch koristuvach with the name MASH. Yaksho MASH launcher

bit, then go to the file є ROOT, and the owner

The process becomes MASH. I have a lot of files that are inaccessible to me

MASH, will be inaccessible to this process, and MASH will not be able to change your

system password. S-bit allows you to extend the rights of the owner (ROOT) to the file on

vlasnik (MASH) to a process (running a file), that for an hour session

robots will process you all files that are available

to the file owner (ROOT).

Accessibility: how to interpret access rights to directories

(some catalogs are also files)? I called to the reading room

directory means that it is allowed to enter the directory and open files

catalog. I have called on the record.

znischuvati files u tsyom katalosis. I called to the vikonannya - tse

There is a lot of joke about this catalosis (for example, with the help of the ls command).

The file system at a glance koristuvach.

Let's see the structure of the file system at a glance

koristuvach. Qia structure will be looked at for public

operating system, some of it is real - the structure can change.

At the root of the catalysis is the file from the unix. This is the file itself,

how to run the program by locking it up, such a form is the kernel

ETC catalog. In general, there are standard data files

systems and commands that will ensure the operation of the control system

system functions. 1. The passwd file. All koristuvachi in

the system is backed up via the whole file. Tse means, shho yaksho

koristuvach can be pratsyuvati, then the passwd file has a row, meanings

im'yam koristuvach, how to take revenge on a set of deyakykh tributes,

the symbol of the distributor. Зокрема, row to the passwd file revenge the number

groups, before what to lay koristuvach, in some way to revenge

password for entering koristuvach to the system. Coding -

means those that in the system of vicarists are mutually ambiguous the possibility of

display of the last symbols in the singing code, and in the system

The password will be displayed. Happy UNIX and save passwords in

near the stolen base danih (if the passwd file also є),

In addition, the passwd file is added to the script for reading, the algorithm for rewriting

You can also change the view, or you can enter the password.

characterizing the prince, the name of the father of the koristuvach; field in yaku

get into the status of a koristuvach; the field in which the "home" directory is indicated.

At a certain number of lines, it has been specified (or maybe it has been specified) with an interpreter

teams tsei koristuvach pratsyuvatime. You can do it too

parameters.

2. The rc file. There are a number of files in the text view.

teams, as there will be a visit before the hour of securing the operating system.

For example, when the operating system is locked up, you can start the process

Perevіrki safe file system.

I wrap up your respect for those operating system UNIX, for a vinyat

kіlkokh vipadkіv, revenge all your system information among the wives

text files. Qia information is easy to look at each other and it is easy

reproach. In its own hour, there will be a revolutionary croc.

3. At the same time, the commanders, who allow

change the passwords of a koristuvach (vikonuvaniy passwd file), allow

"Mount" to the file system and local file systems

update local systems, which allow starting the process

testing and correcting file systems. The process of converting the file

a system for a deyaky set of signs, for example, without

file file when editing files without any problems, give everything

BIN directory. At the same time, the number of standard

system commands available to koristuvachev.

MNT directory. Tse directory, up to which it is possible to "mount" local

file systems Until today, we respected that the file system

spaced out on one annex, but in reality it is not so. Є main

the file system on the system attachment, if

smart boundaries) number of local file systems, i.e.

mounted up to the system and behind the help of the singing command. Root locally

file system and there will be an MNT directory.

DER catalog. At the same time, the files that are associated with

specific drivers outbuildings, for example, console drivers,

line friend meagerly. We'll pam'yataєte, scho files, linked with drivers

zovnishnyh annexes, in the VD, which associations with their own images, may be a sign

in addition, there is a file-attachment, and also may be in the ID according to the

driver tables. Tsi files are mute.

USR directory. Tsei catalog MA pіdcatalogue LIB

there are libraries that implement the functions of the groups,

scho nadajutsya koristuvachev, incl. Сі-compiler from different types

libraries of education.

Also here є the BIN subdirectory (/ USR / BIN)

administrator of the system and additional information "homework" command, more

razmіshennya in katalozі / BIN vvazhaєtsya incorrect.

Subdirectory INCLUDE. Wee pam'yataєte, yak viglyadaє row include .

Tsey row gives a command to the Ci preprocessor to take the file from the directory

/ USR / INCLUDE. Tsey catalog has its own catalogs, and for us tsikaviy

SYS subdirectory (/ USR / INCLUDE / SYS). New include files,

association with systemic capabilities, zokrem signal.h - tse

pererahuvannya quiet signals, as there can be two processes.

From now on, we finished the description of the file system, and we can create files, so

the UNIX file system is archival, rooted for a lot of koristuvachiv. Fileova

UNIX system can do a lot of layer-by-layer buffering for exchanges from

real annexes. UNIX file system є information

the basis of the functionality of the operating system Tse file, which is expanding.

the system, in its own way, take advantage of the integrity, tobto. if you want to

Isnu One way from the root to any university (or arkusha).

The UNIX file system, from a glance of the logical organization of files,

its intelligence and its structure. Tse nakladyє singing umovi

on the administration of the system, because є problems of coordination of access rights to

different components of the file system, є problems of distribution of news

Information at the boundaries of the file system.

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