What kinds of archives are there? Data archiving. Winzip archiver, general information about the program

It is necessary to distinguish between the actual archiver program, the archive format and compression methods. Even the same compression method can have different implementations. For example, there are more than a dozen archiver programs that can create archives in ZIP format. In turn, data in ZIP format can be compressed using various methods: Deflate, Deflate64, BZip2. The Deflate method has several implementations with different speeds and compression ratios. Using this method, the 7-zip archiver allows you to create archives in ZIP and 7Z format.

Typically, archivers can create archives in their own exclusive format using their original methods. For example, the RAR archiver allows you to create RAR archives. The archive format and compression methods are the main advantages of a particular archiver.

In the simplest case, the archiver only allows you to pack or unpack one file. In addition to data compression itself, modern archivers provide some additional functions. There are several main ones:

Compression of some files and entire directories;

Creating self-extracting (SFX) archives. That is, an archiver program is not required to unpack the archive;

Changing the contents of the archive;

Encryption of archive contents;

Information for archive recovery in case of partial damage and the ability to restore damaged archives;

Dividing the archive into several parts or volumes;

Console version of the program for working from the command line;

Graphical (GUI) version of the program.

It is worth noting that, despite the formal presence, the implementation of each additional function can be performed at a completely different level.

In addition to differences in functionality, archivers can be divided into two groups: asymmetric and symmetric. Asymmetric archivers require significantly less time and RAM for the unpacking operation than for the packing operation. This allows you to quickly retrieve archive contents on low-power computers. Symmetric archivers require the same time and amount of RAM for packing and unpacking operations. The use of such archivers on a wide fleet of computers or for quick access to archive contents is limited. The well-known RAR archiver uses the asymmetric dictionary compression method as its main one, and for texts it can use the symmetric PPM method. Therefore, unpacking RAR archives compressed at maximum compression ratio may not be possible on computers with limited RAM. All or almost all advanced high-compression archivers are symmetric.

Despite very modest data on the prevalence of archivers, there are a large number of them. The bulk belongs to the category of experimental and archivers with limited functionality. However, each of them allows you to perform the actual data compression procedure.

Supported platforms: Windows, Linux, BeOS and DOS-32

WinRAR is an archiver of files in RAR and ZIP format for 32-bit and 64-bit Windows and Pocket PC operating systems. It is considered one of the best archivers in terms of the ratio of compression ratio to operating speed. Distributed under a shareware license. The version for the Pocket PC platform has a Freeware license.

Possibilities:

• Creation of archives in RAR and ZIP formats.
• Unpacking files in CAB, ARJ, LZH, TAR, GZ, ACE, UUE, BZIP2, JAR, ISO, 7z, Z formats.
• The ability to encrypt archives using the AES (Advanced Encryption Standard) algorithm with a key length of 128 bits, while the password hash using the SHA-1 algorithm is used as the encryption key.
• Capable of working with files up to 8.589 billion (approximately 8 x 109) gigabytes in size.
• Creation of self-extracting, continuous and multi-volume archives.
• Adding additional information to archives to restore the archive if it is damaged, including the creation of special recovery volumes that allow you to restore a multi-volume archive if parts with information are damaged.
• Full support for the NTFS file system and Unicode file names.
• Command line support.

· Since version 2.90, support for a new archive format is introduced - RAR3. Previous versions cannot work with the new format;

· From version 3.50, themes and skins begin to be supported, and they are also correctly integrated into the context menu on x64 Windows systems;

· Since version 3.60, the compression algorithm supports multi-core processors and processors with Hyper-threading technologies - this provides a significant increase in compression speed;

· Since version 3.70, the archiver is officially compatible with Windows Vista, creates SFX archives with a privilege request;

· Since version 3.80, ZIP archives that contain Unicode file names in UTF-8 format are now supported;

· Since version 3.90, there is a division into 32- and 64-bit versions of the program. The 64-bit version only works on 64-bit Windows operating systems and provides some performance gains.

· Since version 4.00, the RAR archiving algorithm has been changed, which significantly increases the unpacking speed. Depending on the data type, the decompression speed can be up to 30% faster. A password manager appears, which allows you to save archive passwords for future use.

WinZip is a shareware file archiver and compressor for Microsoft Windows and Apple Mac OS X from Corel. PKZIP is the main format, although other archive formats are supported.

Possibilities:

• Creation, addition, extraction from ZIP archives, as well as your own .zipx format
• Supports compression algorithms JPEG, LZMA (12.0), bzip2 (9.0), PPMd (10.0) and special algorithms for audio files (based on WavPack), which allows you to reduce the archive at the expense of a potential increase in compression and extraction time (especially when using PPMd).
• Decompression of .bz2, .rar, .iso, .img, 7-zip files
• Built-in support for LHA archives (.lha and .lzh)
• Customizable integration into the Microsoft Windows shell.
• Supports 128- and 256-bit AES encryption keys. This allowed it to replace the less secure PKZIP 2.0 encryption method used in earlier versions. Version 9 also supports 64-bit encryption in PKZIP.
• Direct burning of archives to CD/DVD
• Backup Automation
• FTP protocol support
• Sending ZIP archives by email
• Unicode support (from version 11.2)

The ZIP format archiver (PKZIP) was originally created for MS-DOS in 1989 by PKWare.

WinZip was created in early 1990 as a commercial GUI for PKZIP. Around 1996, the creators of WinZip incorporated compression code from the PKZIP project, thus eliminating the need for a console version.

From version 6.0 to version 9.0, registered users could download the latest versions of the software using their original registration information, thereby receiving updates for free. Starting from version 10.0, the free update system was disabled. WinZip is available in standard and professional versions.

In May 2006, Corel Corporation, known for its WordPerfect and CorelDRAW product lines, announced that it had completed the acquisition of WinZip Computing.

Before version 11.2, it was possible to enable support for ARC and ARJ archives using external programs.

From version 14.5, the program's graphical shell menu has been changed to a Ribbon interface.

April 2011 - version 15 was released, supporting the Russian language.

2012 - release of WinZip ver. 16.5, the engine of which is optimized for multi-core processors. OpenCL support has also been added for AMD GPUs (however, not for Intel and Nvidia), while the performance increase in this application for Trinity and Llano APUs was up to 45%.

7-Zip is a free file archiver with a high degree of data compression. Supports multiple compression algorithms and multiple data formats, including the proprietary 7z format with the highly efficient LZMA compression algorithm. The program has been developed since 1999 and is free and open source, most of which is freely distributed under the terms of the GNU LGPL license, with the exception of the unRAR decompressor code, which has restrictions. The main platform is Windows (including Windows CE), where two versions of the program are available: with a graphical interface and a command line version. The console version was ported by the developer community to POSIX systems under the general name p7zip. Ported versions for other systems, as well as the original 7-zip program, are available on the SourceForge system website (as of November 7, 2010, the program has been downloaded from the site more than 109 million times). 7-Zip is the winner of the 2007 SourceForge.net Community Choice Awards in the categories of Best Project and Best Technical Design.

Possibilities

• Supported algorithms:
• LZMA, LZMA2, PPMd, Bzip2, Deflate and Deflate64
• Supported formats:
• packing and unpacking: 7z, BZIP2 (BZ2, TB2, TBZ, TBZ2), GZIP (GZ, TGZ), TAR, ZIP, XZ;
• unpacking only: 001, ACE, ARJ, CAB, CHM, CPIO, DEB, DMG, FLV, ISO, JAR, LHA, LZH, LZMA, LZO (TZO), MSI, NSIS, PE, RAR, RPM, SWF, SWM, VHD, WIM, XAR, Z (TAZ); FAT, HFS, MBR, NTFS, UDF, SquashFS, CramFS
• Very high compression ratio in the new 7z format thanks to the improved Lempel-Ziv algorithm.
• For ZIP and GZIP formats, the compression rate is 2-10% higher than that of PKZIP and WinZip.
• Ability to create self-extracting archives for 7z format.
• In the 7z format it is possible to create multi-volume archives (with the exception of self-extracting ones).
• Possibility of encryption using the AES-256 algorithm for 7z and ZIP format archives.
• Integration into the Microsoft Windows and Windows NT shell.
• Plugin for the FAR Manager program.
• Plugin for Total Commander and Unreal Commander (wcx).
• Built-in performance testing utility.
• Multilingual graphical interface (Windows only) with two-window file manager functions.
• Powerful command line version.
• Special version for 64-bit Windows operating systems.
• Unicode encoding support for file names.

7-Zip uses multithreading and allows you to use a different number of threads for compression, depending on the algorithm or format. When creating archives in which files can be compressed independently of each other (for example, ZIP), the program can use up to 8 threads simultaneously. For the LZMA compression algorithm, the archiver can use up to 2 streams simultaneously. The impossibility of using more of them is explained by the sequential nature of continuous compression. The LZMA2 compression algorithm does not have this drawback.

When compressing in the 7z format, special normalizer filters are also used. Thus, for more optimal compression of 32-bit x86 code, normalizing converters BCJ and BCJ2 are used. The program also has an optimizing delta converter for certain types of multimedia data, such as uncompressed 24-bit images.

Compression results are highly dependent on the data being compressed. Typically 7-Zip compresses the 7z format 4-25% better than the zip format.

7-Zip 4.65 ranks 24th in the ranking of archivers by compression ratio; for comparison, the popular WinRAR 3.80 and WinZip 12 rank 32nd and 34th, respectively. The leaders of the PAQ rating, better known for their GUI modification, are KGB and WinRK, which have an order of magnitude longer compression time.

Advantages

• free open source software distributed under the free GNU LGPL license (except for the unRAR unpacker, the license of which prohibits restoring the RAR compression algorithm);. As a result, it supports multiple platforms.
• open archive format and compression algorithm.
• high compression ratio. In general, you can select parameters at which the file size and compression speed will be similar to WinRAR.
• high unpacking speed (for archives with LZMA compression method). According to the author:
• unpacking speed reaches 20-30 megabytes per second on a 2 GHz Intel Core 2 or AMD Athlon 64 processor.
• unpacking speed is about 1-2 megabytes per second when using ARM, MIPS, PowerPC and similar processors at a frequency of 200 MHz.
• multithreaded compression. If on a single-core processor the speed of 7-Zip is close to WinRAR, then on a dual-core processor 7-Zip is much faster;
• AES-256 encryption support;
• support for 64-bit systems;
• the program has many precise settings for compression algorithms; there are ready-made presets for inexperienced users;
• the total volume of files in one 7z format archive can be 16 exabytes;
• There is an open 7-Zip API that allows you to integrate 7-zip with other software products.

Flaws

• Does not save information about file permissions.
• Does not allow files to be extracted if all parts of the archive are not available.

conclusions

Information compression algorithms are being actively improved, and modern archivers make it possible to compress data much more efficiently. However, the most advanced programs in terms of information compression are not always the most multifunctional, and therefore the most widespread. Therefore, most users choose programs that provide a lower compression ratio, but have a well-designed interface and a large number of additional features.

Data compression is used very widely. You could say almost everywhere. For example, PDF documents typically contain compressed information. Quite a lot of EXE executable files are compressed with special compressors. All kinds of multimedia files (GIF, JPG, MP3, MPG) are a kind of archives.

The main disadvantage of archives is the inability to directly access data. They must first be extracted from the archive or unpacked. The unpacking operation, like packing, requires some system resources. This is not an instant operation. Therefore, archives are mainly used with relatively rarely used data. For example, to store backups or installation files.

So, when choosing an archiver, you should not be guided only by the speed of operation and the compression ratio provided. It is necessary that it have a developed and convenient window interface, support different platforms (so that there are no compatibility problems) and have a large number of additional features. It is important when choosing an archiver to take into account the prevalence and possible further support by the authors of new versions.

Bibliography

1. Zverev V.S. Informatics: Textbook for university students. Astrakhan, 2003

2. http://wikipedia.ru

3. Povalyaev. E. “Archivators.” ComputerPress No. 2 2007

4. Volovnik A. “Meet information technologies.” SPb. BHV-Petersburg. 2006

5. Sennov A. “Course of practical work on a PC” St. Petersburg. BHV-Petersburg. 2005

An archive file is a set of one or more files compressed into a single file, from which they can be extracted in their original form if necessary. The archive file contains a table of contents that allows you to find out what files are contained in the archive. The archive's table of contents contains the following information for each file it contains:

· file name;

· information about the directory in which the file is contained;

· date and time of the last modification of the file;

· file size on disk and in archive;

· cyclic control code for each file, used to check the integrity of the archive.

Self-extracting (SFX, from the English SelF-eXtracting) archive is an archive to which an executable module is attached, which allows you to extract files by simply running the archive as a regular program. Thus, no additional external programs are required to extract the contents of the SFX archive. SFX archives, like any other executable files, usually have the extension .EXE.

SFX archives are useful in cases where you need to transfer an archive to someone, but you are not sure that the recipient has the appropriate archiver to unpack it. You can also use SFX archives to distribute your own programs.

Multi-volume archives (archives of several parts)– sequences of archive files (volumes). Tom- these are fragments of an archive consisting of several parts. Typically, volumes are used to store a large archive on several floppy disks or other removable media. Archive volumes do not allow files to be added, updated, or deleted later.

When creating a multi-volume archive in WinRar, the first volume in the sequence has the usual extension .rar, and the extensions of subsequent volumes are numbered as .r00, .r01, r02, etc. Volumes can also be contiguous and self-extracting. The first self-extracting volume has a different (i.e. non-.rar) extension, for example, .exe for DOS or OS/2 SFX volumes).

To unpack volumes, you must start extracting from the first volume (with the .rar extension). If the volumes are on non-removable media (for example, on a hard drive), then you first need to write all the volumes into one folder.

In addition to creating the above types of archives, the WinRar archiver allows you to create continuous (Solid) archives.

Continuous archive is a RAR archive packaged in a special way in which all compressed files are treated as one sequential data stream. Continuous archiving significantly increases the compression ratio, especially when adding a significant number of small, similar files. However, there are some disadvantages of continuous archiving to be aware of:

Continuous archives are updated more slowly than regular archives;

Encrypted continuous archives cannot be modified;

To extract a single file from a continuous archive, all previous archived files must be analyzed, so extracting individual files from the middle of a continuous archive is slower than extracting from a regular archive. However, if all or the first few files are extracted from a continuous archive, then in this case the unpacking speed is almost equal to the unpacking speed of a regular archive;

If any file in a continuous archive is damaged, then all the files following it will not be able to be extracted. Therefore, when saving a continuous archive on an unreliable medium (for example, a floppy disk), it is recommended to add recovery information.

Continuous archives are best used in cases where:

The archive is rarely updated;

There is no need to frequently extract one or more files from the archive;

Compression ratio is more important than compression speed.

Multi-volume and self-extracting archives can also be continuous.

The Backup Wizard provides five types of backups, differing in the selection of data. For example, you can archive only files that have changed since the last backup. Some types of archiving use markers, or archiving attributes, that are determined when files are modified after the backup procedure. When archiving, the attribute is reset.

Normal archiving (Normal type)

All selected files and folders are archived. The backup does not use markers to determine which files are subject to the procedure. Any existing markers are reset and each file is marked as archived. This, by the way, speeds up recovery - the archived files are the latest, and there is no need to restore multiple archives.

Colorful archiving (Soru type)

All selected files are copied without marking them as archived (that is, the archive attribute is not reset). This mode is used when you need to archive individual files in the interval between creating regular and incremental archives, since copy archiving does not affect other results.

Incremental archiving (type Incremental)

Only files created or modified since the last regular or incremental backup are archived. The files are marked as archived (that is, the archive attribute is removed). With both regular and incremental archiving, data recovery requires the presence of both the last regular and all incremental archives.

Differential archiving (Differential type)

Files created or modified since the last regular or incremental backup are archived. Files are not marked as archived (that is, the archive attribute is not removed). When creating a regular and differential archive, restoring files and folders requires both the latest regular and the latest differential archive.

Daily archiving (Daily type)

All files changed during the day prior to the daily backup are copied. Processed files are not marked as archived (that is, the archived attribute is not reset). This mode is used to backup changes made during the day.

Combining backup types

Backup efficiency is achieved by combining different types. Some types of archiving require more time for backup, but less time for restoring information, others - vice versa. When combining different types, it is important to consider the condition of the markers. The Incremental and Differential backup types check and rely on tokens.

Here are some options for combining different

types of archiving.

1. Normal Differential. On Monday, regular archiving is performed, and from Tuesday to Friday, differential archiving is performed. The latter does not reset markers, so each archiving operation covers all changes that have occurred since Monday. In the event of a data failure on Friday, you will only have to restore the Normal archive from Monday and the Differential archive from Thursday. This approach requires more time for backup, but less time for recovery.

2. Normal and Incremental. Regular archiving is performed on Monday, and incremental archiving is performed from Tuesday to Friday. The latter erases markers so that each backup operation only includes files that have changed since the last backup. If there is a data failure on Friday, you will have to restore the Normal archive from Monday and all Incremental archives from Tuesday to Friday. This approach requires less time for backup, but more time for recovery,

3. Normal, Differential and Soru. This method is similar to the first one, which combined the Normal and Incremental types, except that copy archiving is carried out into the environment. The latter covers all selected files, does not erase markers or interrupt the normal backup schedule. Therefore, each of the difference archives includes all changes that have occurred since Monday. The copy archive created on Wednesday is not used if there is a failure on Friday. Copy archiving is needed when you need to create a “snapshot” of data.

End of work -

This topic belongs to the section:

Lecture notes on the discipline Operating systems and environments

Astrakhan region of secondary vocational education.. Astrakhan College of Computer Science.. Lecture notes on the discipline Operating systems and environments semester..

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Operating System Definition
The operating system determines the appearance of the entire computing system. Today there are a large number of operating systems, each of which has its own user implementation features

OS evolution
First period (1945 -1955) The creation of the first digital computers occurred after the Second World War. In the mid-40s, the first tube computing devices were created

Requirements for modern operating systems
Modern operating systems meet the demands of constantly evolving hardware and software. They are able to control the operation of multiprocessor systems and network components

Kernel and auxiliary OS modules
Modern OSs have an architecture based on dividing all its modules into two groups: - kernel - modules that perform the main functions of the OS;

- modules that perform auxiliary
Running the kernel in privileged mode

In order to ensure high reliability and stability, the operating system must occupy a more privileged position in relation to ordinary applications. Operating system
Multi-layer OS structure

A computing system running a kernel-based OS can be depicted as three hierarchically arranged layers: the bottom layer is hardware, the intermediate layer is the kernel, and the top layer is
Microkernel architecture concept

Microkernel architecture is an alternative to the method of constructing an operating system discussed above, according to which all the main functions of the operating system that make up the multilayer
Concepts of computing process and resource

A process (or task) is an abstraction that describes a running program. For the operating system, a process is a unit of work, a request to consume system resources. After
Creating Processes and Threads

The following events can lead to the creation of a process - the need to perform some function that is required for the user program (the creation of a process by the operating system) or
Process control information

o Scheduling and status information – includes information about the state of the process, the priority of the process, the scheduling algorithm used, information about the event due to which the process was found
Process states

Preemptive and non-preemptive scheduling algorithms
Non-preemptive multitasking - non-preemptive multitasking is a method of scheduling processes in which the active process runs until it is on its own initiative, not

Quantization-based scheduling algorithms
Many preemptive scheduling algorithms are based on the concept of quantization. In accordance with it, each process in turn is given a limited continuous period for execution.

Priority-based scheduling algorithms
Servicing processes based on priorities presupposes that threads have some initially known characteristic - a priority, on the basis of which the order of their execution is determined.

Managing Processes and Threads in Windows 2000
Processes in the W2K OS are organized to support various operating environments. Important characteristics of processes in the OS include the implementation of processes as objects, the ability to generate

Processes in Linux
Linux OS uses two categories of processes: system and user. To execute them, two modes are required - user and kernel mode. User processes run as per

Types of interrupts
All computers provide an implementation of an interrupt mechanism, through which devices can interrupt the normal operation of the processor.

Depending on the source, interruptions are divided into
Interrupt handling

An interrupt triggers a series of events that occur in both hardware and software. In Fig. Figure 1.6 shows a typical sequence of these events. After the device is finished working
Goals and means of synchronization

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Methods for dealing with dead ends

The problem of deadlock is extremely serious and complex. The fight against deadlock situations is based on one of three strategies: - preventing deadlocks;
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Types of addresses
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Memory paging
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Segmented memory allocation
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Organization of data input and output
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How cache memory works
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Cache Internals
Let's look at the main elements of the cache. When studying the internal structure of the cache, the following matters: - cache size;

- block size;
- display function;

- algo
I/O using interrupts

The problem with programmable I/O is that the processor must wait a long time until the I/O controller is ready to read or accept new data. While waiting, the processor must
Direct Memory Access

Although interrupt-driven I/O is more efficient than simple programmable I/O, it still takes a lot of CPU time to transfer data between memory and controller
Physical organization of I/O devices

I/O devices are divided into two types: block-oriented devices and byte-oriented devices. Block-oriented devices store information in fixed-size blocks
Speed ​​matching and data caching

When exchanging data, the problem of speed coordination always arises. For example, if one user process produces some data and transfers it to another process through RAM, then
Disk memory for files is not reserved, but allocated as needed. This memory allocation mechanism is called dynamic. The larger the cluster size, the more irrational the use

File management systems
A file is a named memory area on some physical medium intended for storing information.

The file management system is made up of software
File system FAT

A hard drive, having a significantly larger volume than a flexible MD, also has a more complex structure - it can be divided into several sections that act in the system as independent (logical) drives.
Main logical areas of the disk

Starting sector (boot sector, Boot - sector), File Allocation Table (FAT - File Allocation Table), Root Directory (Root-Directory), Data area (about
Key NTFS Features

NTFS is a flexible and powerful file system that, as we'll see, is built on a simple and elegant model. Some of the most noteworthy features of NTFS include the following:
NTFS volume and file structure

NTFS uses the following disk storage concepts: Sector. The smallest unit of physical storage on a disk. The size of the data in bytes is a power of two and is almost always equal to
Physical organization of s5 and ufs

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Checking the availability of network services
If problems are detected with a particular network service, various diagnostic tools are used to check its availability, depending on their availability in a given OS.

Setting up the computer name and workgroup
In a networked environment, each computer has its own name. You can choose this name yourself. It is recommended to associate the computer name with your first or last name, nickname, however, in general

Diagnostics of network settings
If a user contacts support for any reason related to the functioning of the network, the support engineer may ask the user to configure his computer related

Systematic approach to security
The importance and complexity of the security problem requires the development of an information security policy, which implies answers to the following questions: What information to protect?

Windows 2000 overview
Windows 2000 is a multi-purpose OS with built-in support for peer-to-peer and dedicated server networks. The technologies implemented in it make it possible to reduce the total cost of ownership (tota

Control
Windows 2000 creates a more consistent end-user experience by providing the programs, data, and OS settings they need. The following new items should be noted:

Hardware support
Microsoft Windows 2000 Professional currently supports more than 7 thousand device models, including infrared communications devices, scanners, digital cameras and modern multimedia devices

Asymmetric multiprocessing
There are also asymmetric multiprocessor operating systems in which the processors use different areas of physical memory or have other differences. These systems can only run a single process

Safety
Windows 2000 Professional is the most secure desktop OS in the Windows family. Here are some of the distinctive features and security enhancements that make it stand out.

Domains and workgroups
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Before you begin installation
First, review the hardware requirements for installing Windows 2000 Professional and make sure your computer meets these requirements; determine if your hardware is included in the

File systems
After creating the installation partition, Setup will prompt you to select the file system under which this partition will be formatted. Windows 2000 supports three file systems: NTFS, FAT and FAT32.

Licensing
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Using the Management Console and Task Scheduler
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Control console
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Snaps
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Creating and editing a hardware profile
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Activating a Hardware Profile
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Virtual memory
The Windows 2000 memory model is based on a flat, linear 32-bit address space. Windows 2000 uses a virtual memory management system to manage memory.

Virtual address space
A virtual address is an address space that an application uses to reference memory. When a process starts in Windows 2000, VMM provides it with 4 GB of virtual memory.

Paging
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Swap file size
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Productivity increase
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Registry subtrees
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Regedt32.exe program
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Basic structure
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Installing and configuring network protocols
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Sharing ipconfig and ping utilities
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Namespace
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Local accounts
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Account Naming Rules
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Password requirements
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- Always assign a password to account A
Local groups

A Local group is a set of user accounts on a local computer designed to grant access permissions to resources on the computer where the group is created.
Shared folder permissions

Change Create sticks, add files to them, change and (Change) add data in files, change file attributes, delete folders (files) and perform actions allowed by Read permission.
Applying access permissions to a shared folder

The type of access to the shared folder depends on the permissions assigned to user and group accounts. The following discusses the consequences of using different permissions.
- Multiple permissions with

Basic rules for assigning permissions to a shared folder
Application folders are used for server applications that can be accessed by a client computer. The main advantage of shared applications is that you do not need to install software

Assigning access permissions to a shared folder
Once you have opened access to the folder, you must assign the appropriate permissions to user accounts and groups.

1. On the Sharing tab of the folder properties dialog box, click the Perm button
Connecting to a shared folder

You can connect to the shared folder using the Run command, the My Network Places icon, or the Map Network Drive wizard. In the latter case with
Audit Policy Basics

When planning your audit policy, you must determine which computers you will install audit on. By default, auditing is disabled. As you select computers to audit, you can also plan how
There are the following main directions of audit policy

1. Decide whether you need to track system usage trends. If so, plan to archive event logs. This will allow you, for example, to view how system resources are being used,
Windows Backup

Windows 2000 has archiving and recovery tools - the Backup program. The program includes Backup Wizard - a utility program that greatly facilitates archiving
Archiving planning

Archiving is planned and carried out in accordance with the needs and requirements of the enterprise. The main purpose of backup is to be able to restore data if necessary, so any plan
Data recovery

Successful data recovery can only be ensured by adhering to certain rules, such as complete documentation of all archiving activities.
Prepare

Selecting archives and data to be restored
Before starting recovery, you must select the desired data.

You can select individual files or folders, an entire archiving job or several sets. Archive set (backup se
Exploring the capabilities of the cmd utility

The command shell is a separate software product that provides direct communication between the user and the operating system (OS). Text-based command-line user interface
Until now, when giving examples, we assumed that we were entering commands manually every time. When processing a large number of files or when systematically executing the same commands, this becomes an issue.

In the first case, only existing files are deleted; in the second, the disk surface is also checked and defects are eliminated.

Archiving files

The term "archiving" is not entirely accurate. The main purpose of archiver programs is to compress files in order to save memory. Since compressed files are often impossible to work with for their intended purpose, they are used to store copies of files, i.e. for archiving them. The following can be compressed (compacted): files, folders, disks. Compressing files and folders is necessary either for transporting them, or for backup, or for exchanging information over the Internet. Disk compaction is used to improve the efficiency of using their working space (usually for disks of insufficient capacity).

There are many archiver programs that have different indicators for the degree and time of compression; these indicators can be different for different files (text, graphic, executable, etc.), that is, one archiver compresses a text file well, while another compresses an executable one.

Archiver (packer) is a program that allows, through the use of special information compression methods, to create copies of smaller files, as well as combine copies of several files into one archive file, from which you can, if necessary, extract the files in their original form.

The entire range of archivers existing today can be divided into three groups:

which we will conventionally call file, program and disk.

File archivers allow you to pack one or more files (for example, the entire contents of a given subdirectory along with its subdirectories) into a single archive file. The size of the latter is, as a rule, smaller than the total size of the source files, but you cannot use packed programs or data while they are in the archive until they are unpacked. To unpack an archive file, the same archiver is usually used.

Software archivers act differently. They allow you to pack one single file in one go - an executable EXE-type program, but in such a way that the archived program will immediately, after it is launched for execution, self-extract itself in RAM and immediately begin working.

Disk archivers allow you to programmatically increase the available space on your hard drive. A typical disk archiver is a resident driver that, unnoticed by the user, archives any information written to the disk and unpacks it back when read. However

File read/write operations are somewhat slower as the processor takes time to pack and unpack.

For archiving, special programs are used - archivers or archive managers. The most famous archivers: WinZip; WinRar; WinArj. These programs provide the ability to use other archivers, so if the computer where the files compressed in them are transferred does not have the specified programs, the archives can be unpacked using another archiver. Corresponding programs created in MS DOS, but capable of running in Windows, are still widely used.

Almost all archivers allow you to create convenient self-extracting archives (SFX - Self-extracting archives) - files with the .exe extension. To unpack such an archive, you do not need an archiver program; you just need to run the *.exe archive as a program. Many archivers allow you to create multi-volume (distributed) archives, which can be located on several floppy disks.

The main characteristics of archiver programs are:

speed of work;

service (set of archiver functions);

compression ratio - the ratio of the size of the source file to the size of the packed one

The main functions of archivers are:

creating archive files from individual (or all) files of the current directory and its subdirectories, loading up to 32,000 files into one archive;

adding files to the archive;

extracting and deleting files from the archive;

viewing archive contents;

viewing the contents of archived files and searching for strings in archived files;

entering comments to files into the archive;

creation of multi-volume archives;

creation of self-extracting archives, both in one volume and in the form of several volumes;

ensuring the protection of information in the archive and access to files placed in the archive, protection of each of the files placed in the archive with a cyclic code;

testing the archive, checking the safety of information in it;

recovering files (partially or completely) from damaged archives;

support for archive types created by other archivers, etc.

Archive types

Various algorithms are used for compression, which can be divided into reversible

and compression methods with partial loss of information . The latter are more effective, but are used for those files for which partial loss of information does not lead to a significant decrease in consumer properties. Typical lossy compression formats are:

Jpg - for graphic data;

Mpg - for video data;

Mp3 - for audio data.

Typical compression formats without loss of information:

Tif, .pcx and others - for graphic files;

Avi - for video clips;

Zip, .arj, .rar, .lzh, .cab, etc. - for all types of files.

Basic compression algorithms

When talking about compression algorithms, we will mean reversible algorithms.

The RLE (Run-Length Encoding) algorithm uses the principle of identifying repeating sequences. Compression records a sequence of two repeating quantities: the value being repeated and the number of times it is repeated.

Original sequence: 3, 3, 12, 12, 12, 0, 0, 0, 0. Compressed information: 3, 2, 12, 3, 0, 4.

Compression ratio: 6/9*100% = 67%.

KWE (Keyword Encoding) algorithm involves the use of a dictionary in which each word corresponds to a two-byte code. Compression efficiency increases as the volume of encoded text increases.

Huffman algorithm involves encoding not by bytes, but by bit groups. There are three main stages in it.

1) The frequency of repetition of each of the occurring symbols is revealed.

2) The more frequently a character occurs, the fewer bits it is encoded.

3) A correspondence table is attached to the encoded sequence.

Explore the built-in office tools of the Windows operating system and use them to create a lab report. Using the archive manager, get

practical skills in working with archival data. The results of data archiving should be presented in the report, having analyzed the sizes of the source files and their archived copies.

Execution order

1) Working with Microsoft Paint::

– Open Paint via the main menu: Start - Programs - Accessories.

– Using Paint, draw a picture according to the number of your version from the section “ Options for work assignments." The height of the image should be 9 cm.

– Close Paint.

2) Working with the Calculator program:

– Open program Calculator via main menu: Start – Programs –

Standard.

– Through the View menu, change the calculator view to “Engineering”.

sin (5 0.2) * π + ln (N), where N is the number of your option.

– Take a screenshot of an image Desktop window with the open Calculator program with the results of calculations by pressing the Print key on the keyboard

– Open program Paint. Paste the desktop image from the clipboard there.

– Edit the drawing so that only the image of the calculator with the calculation results remains.

– Close Paint and Calculator.

3) Creating archives and working with archived data:

– Open program 7-Zip File Manager via the menu: Start – Programs – 7-Zip.

– Using the file system navigation buttons in the program 7-Zip File Manager go to the folder where the Image_Lab32 and

– Select these two files and click onToolbars Add button.

– In the window that opensAdd to archive enter the name of the archive Drawings,

Archive format – Zip, Compression level – Ultra . Please note that

what other parameters does the archive have, but leave them unchanged.

– Click OK and watch the archive creation process. The file Drawings.zip should appear in the program window

– Take a screenshot of the program window image 7-Zip File Managerby pressing the keyboard shortcut “Alt+Print Screen”;

– Open program Paint. Paste the image from the clipboard there.

– Close the program Paint.

– A new file appears in the archiver window Arh_Lab32.bmp. Using the context menu on this file, select the menu item “7-Zip” – “Add to archive...”

– In the archive name input field, select the archive name from the pop-up list Pictures and click OK.

– Close the program 7-Zip File Manager.

– In your personal folder, create a folder " Archived files" and move the file there

Drawings.zip.

– By calling the context menu on the archive with the mouse Pictures.zip, select “7-Zip”

– “Extract to “Drawings\””)

4) Creating a lab report in WordPad:

– Open program WordPad via the main menu: Start – Programs –

Standard.

– Using this program, prepare a laboratory work report using the template shown in the figure below. Inserting the necessary pictures is done from your personal folder through the program menu item:“Insert” - “Object...”- switch " Create from file". Font used: Times

5) Report to the teacher when completed.

Control questions

1) What standard programs come with Windows?

2) How to run standard Windows applications?

3) What is the purpose of Notepad?

4) What types of text files can Notepad edit?

5) What is a cursor?

6) How do you switch fonts in Notepad?

7) How are font parameters set?

8) What are the main types of fonts and their characteristics?

9) How to open a document in Notepad?

11) What are the main features of editing a document in Notepad?

12) What is a clipboard?

13) How can you put an object on the clipboard?

14) How to paste an object from the clipboard into a document?

15) List the main elements of the Notepad window and indicate their functional purpose.

16) What editors are called graphic editors? What is their purpose?

17) How is an image constructed in raster graphics? in vector?

18) What type of editor - raster or vector graphics is the Paint graphic editor?

19) What drawing tools are available on the Paint toolbar? What is their purpose?

20) What is the purpose of the color picker and editor tool customization palette?

21) Where are the coordinates of the graphics cursor displayed?

22) What is the difference between a text editor and a word processor?

23) What does the document formatting feature include?

24) What are the main formatting features included in Word Pad? How are they implemented?

25) What formats does WordPad allow you to save documents in?

26) What is the Calculator used for?

27) What types of calculators are included in Windows? How do you switch from one type of calculator to another?

28) What are the main features of simple and engineering calculators?

29) What is OLE technology?

30) What is an OLE object, OLE server, OLE client?

31) In what ways can you embed and associate external objects with a destination document?

32) List and describe ways of connecting an object OLE server with document receiver.

33) Compare the methods of embedding and linking objects.

34) To what extent do various Windows applications support OLE technology? Give examples.

35) What are the possibilities OLE technologies?

36) What is the purpose of Windows utilities?

37) How do I access Windows utilities?

38) What is Check Disk used for?

39) How often should I perform a standard and full hard drive scan?

40) What is the purpose of a disk defragmenter program?

41) What is disk defragmentation?

42) What is disk formatting? In what cases do you use formatting?

43) How can I format a disk?

44) What are the features of quick and complete disk formatting?

45) What is the purpose archiving programs?

46) What are compressed files and folders used for?

47) What programs are called archivers?

48) By what indicators do they differ? Archiving programs?

49) What are the capabilities of disk archivers?

50) List the most famous archivers.

51) What archives are called self-extracting? How are such archives unpacked?

52) What archives are called multi-volume?

53) What are the main characteristics archiving programs?

54) What are the main functions of archivers?

55) What types of compression algorithms can be divided into?

56) How do lossless compression algorithms differ from lossless compression algorithms?

57) What are the typical lossy and lossless compression formats?

58) What are the main compression algorithms?

	Options for work assignments
	Figure No.

10 A4

11 B4

12 C4

13 A5

14 B5

15 C5

16 A6

17 B6

18 C6

19 A7

20 B7

21 C7

22 A8

23 B8

24 C8

25 A9

26 B9

27 C9

28 A10

29 B10

30 C10

The way you archive files depends on the type of data being saved, how easy it is to restore it, etc. If you look at the properties of a file or directory in Windows Explorer, you will see the Archive attribute. It indicates whether the given file/directory can be archived. If the attribute is enabled, then the file/directory may need to be archived. The main types of archiving are:

Regular/full archiving. All selected files are archived regardless of the archive attribute value. After archiving a file, the archive attribute is reset. If the file is then modified, the archive attribute is turned on, indicating that the file needs to be archived.

Copy archiving. All selected files are archived regardless of the archive attribute value. Unlike regular archiving, the archive attribute is not changed. This then allows you to perform another type of archiving.

Differential archiving. Creates backup copies of files that have changed since the last normal backup. The presence of the archive attribute indicates that the file has been modified. Only files with this attribute will be archived. But the archive attribute does not change. This then allows you to perform another type of archiving.

Incremental archiving. Creates backup copies of files that have changed since the last regular or incremental backup. The archive attribute indicates that the file has been modified. Only files with this attribute will be archived. After archiving files, the archive attribute is reset. If a file has been modified, the archive attribute is turned on, indicating that the file requires archiving.

Daily archiving. Files modified over the past day are saved. This type of archiving does not change the attributes of the archived files. You can perform full backups weekly, plus daily, differential, and incremental backups. You can also create an extended archive set for monthly and quarterly archives, which will include files that are archived on an irregular basis. Tip Sometimes weeks or months pass before anyone realizes that a file or data source is missing. Therefore, when planning monthly or quarterly backups, do not forget that you may also need to recover outdated data.

Differential and incremental archiving

Currently, the best archiver for Windows is WinRAR.

WinRAR features:

WinRAR features:

Allows you to unpack archives CAB, ARJ, LZH, TAR, GZ, ACE, UUE, BZ2, JAR, ISO, and provides archiving of data in ZIP and RAR formats

Provides full support for ZIP and RAR archives

It has special algorithms optimized for text and graphics. For multimedia, compression can only be used with RAR formats

Supports drag & drop technology

Has a command line interface

Can perform continuous archiving, which provides higher compression rates than conventional compression methods, especially when packing large numbers of small files of the same content

Provides support for multi-volume archives, that is, it splits the archive into several volumes (for example, to write a large archive to disks). Volume expansion: RAR, R01, R02, etc. With a self-extracting archive, the first volume has the EXE extension

Creates self-extracting archives (SFX), regular and multi-volume archives, and protects them with passwords

Provides recovery of physically damaged archives

Has recovery tools that allow you to restore missing parts of a multi-volume archive

Supports UNICODE in file names

For beginners, there is a Wizard mode, with which you can easily carry out all operations on archives

WinRAR has other additional features. WinRAR is capable of creating an archive in two different formats: RAR and ZIP. Let's look at the advantages of each format.