Files and file structures Computer as a universal device. A graphic representation of a hierarchical file structure is called What is the name of a geographical representation of a hierarchical file structure

"File archive" - File system server. ftp client. File exchange program - ftp. Server file system2. User. FTP protocol. Server protocol interpreter1. Server Data Transfer Program2. data. Data channel. Use of archives. The server usually starts when the computer boots up. Data exchange in FTP takes place over a TCP channel.

"Image in Word" - Working with pictures in text editor Microsoft Word. Selection of lines, arrows, shapes. Hello! Reset picture settings. Consider the Draw panel menu. Actions with drawings. Brightness change. Exercise. Two buttons on the Drawing panel will help you add a picture, add a picture. To create the shadow of an object.

"Image" - Image compression. Representation of images. Omit encoding to binary values. Exercises. Next, check neighboring areas for homogeneity and merge where possible. Image database search. Then restore (decode) the image. Database structures for images. Sample database architecture for images.

“The body is called a cylinder” - The height of the cylinder is 8 m, the radius of the base is 5 m. The cylinder is crossed by a plane so that the cross section is a square. Solution: The project "Mathematics in the profession "Cook, confectioner". Task number 3. Cylinder. A regular hexagonal prism is inscribed in a cylinder. Find the length (h) of the OK perpendicular. 4) According to the condition AB \u003d A "B" \u003d M "\u003d 8. In a right-angled triangle AOK, the leg AK \u003d 4. Then, according to the Pythagorean theorem, h \u003d OK \u003d \u003d\u003d 3 m.

"Creating graphic images" - The AutoShape button is designed to draw various geometric shapes. AutoShapes. Comparative characteristics raster and vector graphics. The position of the graphic image in the text. Inserting a picture from a file. Inserting a picture from the collection Microsoft office. Insert? Drawing? From file. Insert a picture from the collection into text.

"Computer graphics" - Raster graphics. Large amounts of data. Each point of the screen can have only two states - "black" or "white". File formats raster graphics. A pixel is the smallest element of a bitmap. Computer graphics. Color images can have different color depths (bits per dot 4, 8, 16, 24).

There can be several disk drives on one computer - devices for working with disks. Each drive is assigned a one-letter name (followed by a colon), such as A:, B:, C:. often on personal computers a large capacity disk built into the system unit (it is called a hard disk) is divided into sections. Each of these partitions is called a logical drive and is named C:, D:, E:, etc. The names A: and B: usually refer to small removable disks - floppy disks (floppies). They can also be considered as the names of disks, only logical ones, each of which completely occupies a real (physical) disk. Therefore, A:, B:, C:, D: are all names of logical drives.

The name of the logical drive containing the file is the first "coordinate" that specifies the location of the file.

3. File structure of the disk

The whole set of files on the disk and the relationships between them is called the file structure. Different operating systems may support different organization of file structures. There are two types of file structures: simple, or single-level, and hierarchical - multi-level.

A single-level file structure is a simple sequence of files. To find a file on a disk, it is enough to specify only the file name. For example, if the file tetris.exe is located on drive A:, then its "full address" looks like this: A:\tetris.exe

Operating systems with a single-level file structure are used on the simplest educational computers equipped only with floppy disks.

A multi-level file structure is a tree-like (hierarchical) way of organizing files on a disk. To facilitate understanding of this issue, we will use the analogy with the traditional "paper" way of storing information. In such an analogy, the file is presented as some titled document (text, drawing) on ​​paper sheets. The next largest element of the file structure is called a directory. Continuing the "paper" analogy, we will represent the directory as a folder in which you can put a lot of documents, i.e. files. The directory also gets its own name (imagine that it is written on the cover of the folder).

A directory can itself be part of another directory external to it. This is similar to how a folder is nested inside another larger folder. Thus, each directory can contain many files and subdirectories (called subdirectories) within it. catalog itself top level, which is not nested in any other directory, is called the root directory.

IN operating system Windows uses the term "folder" to refer to "directory".

A graphic representation of a hierarchical file structure is called a tree.

On fig. 2.1 directory names are written in uppercase letters, and files - lowercase. Here in the root directory there are two folders: IVANOV and PETROV and one file fin.com. The IVANOV folder contains two subfolders PROGS and DATA. The DATA folder is empty; there are three files in the PROGS folder, and so on. In the tree, the root directory is usually represented by a symbol.

Rice. 3.1. An example of a hierarchical file structure

Keywords:

• logical name of the external storage device
• file naming rules
• catalog
• root directory
• file structure
• the path to the file
• full filename

2.4.1. Logical names of external storage devices

Each computer can have multiple external storage devices connected to it. The main external memory device of a PC is HDD. If the hard disk has a sufficiently large capacity, then it is divided into several logical partitions.

The presence of several logical partitions on one hard disk provides the user with the following benefits:

• you can store the operating system in one logical partition, and the data in another, which will allow you to reinstall the operating system without affecting the data;
• you can install different operating systems on one hard disk in different logical partitions;
• maintenance of one logical partition does not affect other partitions.

Each external storage device connected to the computer, as well as each logical partition hard drive have a logical name.

In the operating room Windows system accepted logical names of external memory devices, consisting of one latin letter and a colon sign:

• for floppy disk drives (floppy disks) - A: and B:;
• For hard drives and their logical partitions - C:, B:, E: it. d.;
• for optical drives - the names that follow alphabetically after the name of the last hard disk or hard disk partition on the computer (for example, F:);
• for flash memory attached to the computer, the name following the last name of the optical drive (for example, G:).

The Linux operating system has different rules for naming disks and their partitions. For example:

• logical partitions belonging to the first hard disk are named hdal, hda2, etc.;
• logical partitions belonging to the second hard drive are named hdbl, hdb2, etc.

2.4.2. File

All programs and data are stored in the computer's external memory as files.

The file system is a part of the operating system that determines how files are organized, stored and named on storage media.

A file is characterized by a set of parameters (name, size, creation date, last modification date) and attributes used by the operating system to process it (archive, system, hidden, read-only). The file size is expressed in bytes.

The file name usually consists of two parts separated by a dot: the actual file name and the extension. The actual name of the file is given by the user. It is recommended to do this meaningfully, reflecting the contents of the file in the name, although the user can set an arbitrary set of characters as the name. The name extension is usually set automatically by the program when the file is created. Extensions are optional, but they are widely used. The extension allows the user, without opening the file, to determine its type - what kind of information (program, text, picture, etc.) it contains. The extension allows the operating system to automatically open the file.

In modern operating systems, the file name can include up to 255 characters, and it can use letters of national alphabets and spaces. The file name extension is written after the dot and usually contains 3-4 characters.

On Windows, the following characters are not allowed in a filename: \, /, :, *, ?, ", |. On Linux, these characters, except /, are allowed, although they should be used with caution, as some of them may have a special meaning, as well as for reasons of compatibility with other operating systems.

The Linux operating system, unlike Windows, distinguishes between lowercase and uppercase letters in a file name: for example, FILE.txt, file.txt, and FiLe.txt are three different files in Linux.

The table shows the most common file types and their extensions:

The following types of files are distinguished in Linux OS:

• ordinary files - files with programs and data;
• directories - files containing information about directories;
• links - files containing links to other files;
• special device files - files used to represent the physical devices of a computer (hard drives, optical drives, printer, sound speakers etc.).

2.4.3. Catalogs

Each computer storage medium (hard disk, optical disk or flash memory) can store a large number of files. For the convenience of finding information, files are grouped into groups, called directories or folders, according to certain criteria.

The directory also gets its own name. It can itself be part of another directory external to it. Each directory can contain many files and subdirectories.

The top-level directory is called the root directory.

OS Windows any information carrier has a root directory that is created by the operating system without user intervention. Root directories are denoted by adding "\" (backslash) to the logical name of the corresponding external memory device: A:\, C:\, D:\, E:\, etc.

In Linux, directories on hard drives or their logical partitions do not belong to the top level of the file system (they are not root directories). They are "mounted" to the mnt directory. Other external storage devices (floppy, optical, and flash drives) are "mounted" in the media directory. The mnt and media directories, in turn, are "mounted" into a single root directory, which is denoted by the "/" sign (forward slash).

2.4.4. Disk file structure

File structures are simple and multi-level (hierarchical).

Simple file structures can be used for disks with a small (up to several tens) number of files. In this case, the table of contents of the disk is a linear sequence of file names (Fig. 2.8). It can be compared to the table of contents of a children's book, which contains the names of the stories included in it and page numbers.

Rice. 2.8.
Simple file structure

Hierarchical file structures are used to store large (hundreds and thousands) number of files. Hierarchy is the arrangement of parts (elements) of the whole in order from highest to lowest. The initial (root) directory contains files and subdirectories of the first level. Each of the first-level directories can contain files and subdirectories of the second level, and so on (Figure 2.9). In this case, the table of contents of the disk can be compared with the table of contents of our textbook: it contains chapters consisting of paragraphs, which, in turn, are divided into separate paragraphs, etc.

Rice. 2.9.
Hierarchical file structure

The user, combining files into directories at his own discretion, gets the opportunity to create a convenient information storage system. For example, you can create separate directories to store text documents, digital photos, melodies, etc.; in the catalog for photos, combine photos by years, events, accessories, etc. Knowing which directory a file belongs to makes finding it much faster.

A graphic representation of a hierarchical file structure is called a tree. On Windows, directories on different drives can form several separate trees; in Linux, directories are combined into a single tree common to all drives (Figure 2.10). Tree-like hierarchical structures can be displayed vertically and horizontally.

Rice. 2.10.
Directory Tree in Linux OS

2.4.5. Full file name

To access the desired file stored on a certain disk, you can specify the path to the file - the names of all directories from the root to the one in which the file is directly located.

In operating system windows way to file starts with the logical name of the external storage device; Each subdirectory name is followed by a backslash. On the Linux operating system, the file path starts with the name of a single root directory; Each subdirectory name is followed by a forward slash.

The path to the file and the file name written in sequence form the full file name. There cannot be two files that have the same full name.

An example of a full filename in Windows OS:

E:\images\photo\Katun.jpeg

An example of a full filename in Linux OS:

/home/method/text

Task 1. The user worked with the C:\Physics\Problems\Kinematics directory. First, it went up one level, then went up one level again, and then went down to the Exam directory, which contains the Computer.doc file. What is the path to this file?

Solution.

The user worked with the C:\Physics\Problems\Kinematics directory. Having risen one level up, the user found himself in the C:\Physics\Problems directory. Having risen one more level up, the user ended up in the C:\Physics directory. After that, the user went down to the Exam directory where the file is located. The full path to the file looks like: С:\Physics\Exam

Task 2. The teacher worked in the directory D:\Lessons\8th grade\ Practical work. Then I moved up a level in the directory tree, went down to the Presentation subdirectory and deleted the Introduction.ppt file from it. What is the full name of the file that the teacher deleted? Solution.

The teacher worked with the directory D:\Lessons\8th grade\Practical work. Having risen one level up, he ended up in the directory D: \ Lessons \ 8th grade. After that, the teacher went down to the Presentations directory, the path to the files of which looks like: D:\Lessons\Class 8\Presentations. In this directory, he deleted the file Introduction.ppt, the full name of which is D:\Lessons\8 class\Presentation\Introduction.ppt

2.4.6. Working with files

Files are created using programming systems and application software.

In the process of working on a computer on files, the following operations are most often performed:

• copying (a copy of the file is created in another directory or on another medium);
• moving (the file is transferred to another directory or to another medium, the original file is destroyed);
• renaming (renames the file name itself);
• deletion (the object is destroyed in the source directory).

When searching for a file whose name is not known exactly, it is convenient to use the file name mask. The mask is a sequence of letters, numbers, and other characters allowed in file names, among which the following characters may also occur: "?" (question mark) - means exactly one arbitrary character; "*" (asterisk) - means any (including empty) sequence of characters of arbitrary length. For example, the mask n*.txt will find all files with the extension txt whose names begin with the letter "p", including the file n.txt. The mask n?.* will find files with arbitrary extensions and two-letter names starting with the letter "n".

The most important

The hard drive is the main storage device in a PC. If the hard disk has a sufficiently large capacity, then it is divided into several logical partitions. Each external storage device connected to the computer, as well as each logical partition of the hard disk, has logical names.

A file is a named area of ​​external memory. The file name usually consists of two parts separated by a dot: the actual file name and the extension.

A directory is a named collection of files and subdirectories (subdirectories). The top-level directory is called the root directory.

The file structure of a disk is a collection of files on a disk and the relationships between them. File structures are simple and multi-level (hierarchical).

Path to the file - the names of all directories from the root to the one in which the file is directly located. The path to the file and the file name written in sequence form the full file name. The full filename is unique.

Questions and tasks

Description of the presentation FILES AND FILE STRUCTURES A COMPUTER AS A UNIVERSAL DEVICE on slides

Keywords logical name of the external storage device file file naming rules directory root directory file structure file path full file name

Logical Names of External Storage Devices Each external storage device that you connect to your computer has a logical name. In Windows OS, logical names of external memory devices are accepted, consisting of one Latin letter and a colon sign: for floppy disk drives (floppy disks) - A: and B: for hard drives and their logical partitions - C:, D: C (C:) D (D:) for optical drives - the names following alphabetically after the name of the last hard disk or hard disk partition on the computer DVD disc RW drive (E:) A (A:) for flash memory connected to the computer - the name following the last name of the optical drive (for example, F:) Removable disk (F:) Linux has different rules for naming drives and their partitions . For example: logical partitions belonging to the first hard disk are named hda 1 , hda 2 , etc. ; logical partitions belonging to the second hard disk are named hdb 1 , hdb 2 , etc.

A file is a named area of ​​external memory. The file system is a part of the operating system that determines how files are organized, stored and named on storage media. Document files are created and processed using application files. Document Application Graphic Text Application program. File. The file name consists of two parts separated by a dot: the actual file name and the extension. The actual name of the file is given by the user. The name extension is usually set automatically by the program when the file is created. File type Extension examples System file drv, sys Text file txt, rtf, docx, odt Graphic file bmp, gif, jpg, tif, png, pds Web page htm, html Sound file wav, mp 3, midi, kar, ogg Video file avi, mpeg Archive zip, rar Spreadsheet xls, ods Program code (text) bas, pas

Directories A directory is a named collection of files and subdirectories (subdirectories). The top-level directory is called the root directory. In Windows operating systems, root directories are indicated by adding "\" (A: \, C: \, D: \, E: \) to the logical name of the corresponding external storage device. In Linux operating systems, hard drive directories are not root directories. They are "mounted" to the mnt directory. Other external storage devices (floppy, optical, and flash drives) are "mounted" in the media directory. The mnt and media directories, in turn, are "mounted" into a single root directory, which is denoted by the "/" sign.

File structure of a disk The file structure of a disk is a collection of files on a disk and the relationships between them. Simple file structures can be used for disks with a small (up to several tens) number of files. ——— ——— ——— ——— ——— ——— —— A: \ d 1. txt d 2. txt d 3. txt d 4. txt d 5. txt

File structure of a disk The file structure of a disk is a collection of files on a disk and the relationships between them. Hierarchical file structures are used to store large (hundreds and thousands) number of files. A graphic representation of a hierarchical file structure is called a tree. —— —— —— —— —— —— —— —— —— E: \ video recording. avi chart. xls texts letter. txt numbers. txt images photo of Biya. jpeg Katun. jpeg Onegin. doc aquarium. bmp ringtone. mp

Disk file structure In Windows, directories on different disks can form several separate trees. In Linux, directories are combined into a single tree that is common to all drives. Tree-like hierarchical structures can be displayed vertically and horizontally. bin home usr var … shogun methody bin etc doc … -filename-with-text

Full file name Path to the file - the names of all directories from the root to the one in which the file is directly located. On Windows, the file path starts with the logical name of the external storage device; after the name of each subdirectory, a backslash is put: E: \images\photos\Katun. jpeg On Linux, the file path starts with the name of a single root directory; Each subdirectory name is followed by a forward slash: /home/methody/text The path to the file and the filename written in sequence form the complete filename. There cannot be two files that have the same full name.

The user worked with the directory C:\Physics\Problems\Mechanics. First it went up one level, then it went up one level again, and after that it went down to the Exam directory, which contains the Questions file. doc. What is the path to this file? Solution: Problem 1 C: Physics Problem. The user worked with the Mechanic catalog. Going up one level, he found himself in the directory: Going up another level, he ended up in the directory: After that, he went down to the directory Exam: Exam The full path to the file looks like: C: \Physics\Exam.

Task 2 The teacher worked in the directory D: \Lessons\7th grade\Practical work. Then he moved to a higher level in the directory tree, went down to the Presentation subdirectory and deleted the Introduction file from it. ppt. What is the full name of the file that the teacher deleted? Solution. The user worked with the catalog: Lessons Grade 7. D: Practical work. Going up one level, it ended up in the directory: Going down one level, it ended up in the Presentations: Presentations directory. In the Presentations directory, he deleted the file Introduction. Full name remote file: D: \Lessons\7th grade\Presentation\Introduction. ppt

Working with files Files are created using programming systems and application software. Basic operations with files: copying (a copy of the file is created in another directory or on another medium); moving (the file is transferred to another directory or to another medium, the original file is destroyed); renaming (renames the file name itself); deletion (the object is destroyed in the source directory). Operate with files and folders. swf. When searching for a file, you can use a filename mask, which is a sequence of letters, numbers, and other characters allowed in filenames, including: ? (question mark) - means exactly one arbitrary character; * (asterisk) - means any (including empty) sequence of characters of arbitrary length. For example, by mask n? . * will find files with arbitrary extensions and two-letter names starting with the letter "n".

Most importantly, a File is a named area of ​​external memory. The file name consists of two parts separated by a dot: the actual file name and the extension. A directory is a named collection of files and subdirectories (subdirectories). The top-level directory is called the root directory. The file structure of a disk is a collection of files on a disk and the relationships between them. File structures are simple and multi-level (hierarchical). Path to the file - the names of all directories from the root to the one in which the file is directly located. The path to the file and the file name written in sequence form the full file name. The full filename is unique.

Questions and tasks What is a file? What are the basic rules for naming files in the operating system installed on the computers in your class? What are the names of programs you know that open files with the following extensions: txt, doc, bmp, rtf, arj. What are the logical names of the external storage devices on the computer to which you have access. What is a directory? What is the root directory? How can files be organized in external storage? What is the graphic representation of a hierarchical file structure called? What is the path to a file on disk? What is the full filename? List the basic operations performed with files. File Pushkin. doc is stored on the hard drive in the POETRY directory, which is a subdirectory of the LITERATURE directory. The table shows fragments of the full file name: Restore the full file name and encode it with letters (write down the sequence of letters without spaces and commas). Sasha worked with the directory: D:\LESSONS\INFORMATICS\PRACTICAL WORKS. It went up two levels, then went down to the ALGEBRA subdirectory and created the Qur file in it. txt. What is the full name of the file that Sasha created? The user worked with the directory: D:\DOCUMENTS\PHOTO\2011\SPRING. First, he went up three levels, then went down to the EXAM directory, and after that he went down to the COMPUTER SCIENCE directory. Specify the full path for the directory where the user ended up. 1) D: \ DOCUMENTS\PHOTO\INFORMATICS 2) D: \ DOCUMENTS\INFORMATICS\EXAM 3) D: \ DOCUMENTS\EXAM\INFORMATICS 4) D: \ DOCUMENTS\PHOTO\2011\SPRING\EXAM\INFORMATICSFrom the list of names, select ( tick) those that satisfy the mask? l*ck. *t? click. txt black. ppt lock. sts clock. tt blink. uta applock. stu blocker. htm elpack. ty blocker. html. From the list of names, select (tick) those that do NOT match the mask? l*ck*. *? :_click. txt black. ppt lo 3 ck. sts clock. tt blink. uta applock. stu blocker. htm elpack. ty blocker. html. Which of the following file names match the mask? ese*ie. ? t* 1. seseie. ttx 2.esenie. ttx 3.eseie. xt 4. sesenie. txt A B C D E F LITERATURE C: Pushkin \. doc POETRY

Reference Note A file is a named area of ​​external memory. Each external storage device connected to the computer has a logical name (A: B: C: D: E: F: ...) File search Full file name Address File name drive: \path name. extension Simple Hierarchical Disk File Structure File type Extension examples System file drv, sys Text file txt, rtf, docx, odt Graphic file bmp, gif, jpg, tif, png, pds Audio file wav, mp 3, midi, kar, ogg Video file avi, mpeg Archive zip, rar Spreadsheet xls, ods