Files and file structures Computer as a unifood device. The graphic image of the hierarchical file structure is called how the graphic image of the hierarchical file structure is called

On one computer there can be several drives - devices with disks. Each drive is assigned a single-bore name (after which the colon is put), for example, and:, in:, s:. Often on personal computers, a large capacity disk embedded in the system unit (it is called hard disk), divided into sections. Each of these sections is called a logical disk, and it is assigned a name from :, D :, E: etc. Names A: and in: usually refer to interchangeable discs of small volume - flexible disks (flop). They can also be considered as disk names, only logical, each of which is fully occupied by the real (physical) disk. Consequently, A:, in:, with:, D: - These are all logical disks.

The name of the logic disk containing the file is the first "coordinate", which defines the location of the file.

3. Disc file structure

The entire set of files on the disk and the relationship between them is called the file structure. Various OSs can support different file structures. There are two varieties 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 the disk, just specify the file name. For example, if the Tetris.exe file is on the disk A: then its "full address" looks like this: A: \\ Tetris.exe

Operating systems with a single-level file structure are used on the simplest training computers equipped with only flexible discs.

A multi-level file structure - a tree-shaped (hierarchical) method of organizing files on a disk. To facilitate understanding of this issue, we use the analogy with the traditional "paper" method of storing information. In such analogy, the file seems to be some entitled document (text, drawing) on \u200b\u200bpaper sheets. The next largest element of the file structure is called a catalog. Continuing the "paper" analogy, the directory will be submitted as a folder into which you can attach a lot of documents, i.e. files. The directory also receives its own name (imagine that it is written on the folder cover).

The catalog itself can be part of another, external in relation to the directory. This is similar to how the folder is invested in another folder of the larger size. Thus, each directory may contain a lot of files and nested directories within itself (they are called subdirectors). The top-level directory that is not invested in any other directory is called the root directory.

In the Windows operating system, the term "folder" is used to refer to the concept "directory".

The graphic image of the hierarchical file structure is called wood.

In fig. 2.1 Directory names are written by capital letters, and files are flat. Here in the root directory there are two folders: Ivanov and Petrov and one FIN.COM file. The Ivanov folder contains two invested Progs and Data folders. Data folder - empty; In the ProgS folder there are three files, etc. On a tree, the root directory is usually depicted by a symbol.

Fig. 3.1. Example hierarchical file structure

Description Presentation Files and File Structures Computer as a Unifimate Slides Device

Keywords Logical Name of the External Memory Device File file naming files directory root directory file structure path to file full file name

Logical Names of external memory devices Each external memory connected to the computer has a logical name. In Windows, the logical names of the external memory devices consisting of one Latin letter and a colon mark are taken: for floppy disk drives (floppy disks) - A: and in: for hard drives and their logical partitions - C:, D: C (C :) D (D :) For optical drives - names following alphabetics after the last name of the last Hard disk or partition of the hard disk DVD RW drive (E :) A (A :) for the flash memory connected to the computer - the name following The last name of the optical drive (for example, F :) Removable disk (F:) In Linux, other rules of the naming of the disks and their sections are taken. For example: logical partitions belonging to the first tough disc, receive the names of HDA 1, HDA 2, etc.; Logical sections belonging to the second rigid disk receive the names of HDB 1, HDB 2, etc.

The file is the named area of \u200b\u200bexternal memory. The file system is part of the OS, which defines the method of organizing, storing and naming files on media information. Documents files are created and processed using application files. Document application Graphic text application program. File. The file name consists of two parts separated by the point: the file name and extension itself. Actually the file name gives the user. The name extension is usually specified by the program automatically when creating a file. File File Extensions Systems System File DRV, SYS Text File TXT, RTF, DOCX, ODT Graphic File BMP, GIF, JPG, TIF, PNG, PDS Web Whelper HTM, HTML Sound File WAV, MP 3, MIDI, KAR, OGG Video Faille AVI, MPEG Archive ZIP, RAR Network Table XLS, ODS Code (text) BAS, PAS

Catalogs The directory is a named set of files and subdirectories (nested directories). The top-level directory is called the root directory. In Windows, the root directories are designated by adding a "\\" (A: \\, C: \\, D: \\, E: \\, C: \\, D: \\, E: \\) to the logical name (A: \\, C: \\, D: \\, E: \\) in Linux directories are not root directories. They are "mounted" in the MNT catalog. Other external memory devices (flexible, optical and flash drives) are "mounted" to the Media catalog. MNT and Media catalogs, in turn, are "mounted" into a single root directory, which is indicated by the "/" sign.

The file structure of the disk file structure is a set of files on disk and interconnections between them. Simple file structures can be used for disks with a small (up to several tens) files. --- --- --- --- --- - a: \\ d 1. TXT D 2. TXT D 3. TXT D 4. TXT D 5. TXT

The file structure of the disk file structure is a set of files on disk and interconnections between them. Hierarchical file structures are used to store large (hundreds and thousands) the number of files. The graphic image of the hierarchical file structure is called wood. - - - - - - - - - E: \\ Video recording. AVI schedule. XLS Texts Letter. TXT numbers. TXT image photo of baby. JPEG Katun. JPEG Onegin. Doc Aquarium. BMP melody. MP

The file structure of the disk in Windows directories on different disks can form several separate trees. In Linux, catalogs are combined into one tree, common to all disks. Vidoid hierarchical structures can be depicted vertically and horizontally. Bin Home Usr Var ... SHOGUN METOHODY BIN ETC DOC ... -FILENAME-WITH- TEXT

The full name of the file path to the file is the names of all directories from the root to the one in which the file is directly located. In Windows, the path to the file begins with the logical name of the external memory device; After the name of each subdirector, the reverse slash is put: E: \\ Images \\ photo \\ Katun. JPEG in the Linux OS path to the file begins with the name of the single root directory; After each subdirectory name, a direct slash is installed: / Home / Methody / Text The consistently recorded path to the file and the file name constitutes the full name of the file. There can be no two files that have the same full names.

The user worked with a catalog C: \\ Physics \\ Tasks \\ Mechanic. At first he rose to one level up, then once again rose to one level up and then descended into the catalog of the exam in which the file is located. Doc. What is the path to this file? Solution: Task 1 C: Task physics. The user worked with the mechanic catalog. Having rising one level upwards it was in the directory: Rising another level upwards it turned out to be in the directory: After that, he went down to the Exam directory: Exam Full Path to the file is: C: \\ Physics \\ Exam.

Task 2 Teacher worked in the catalog D: \\ Lessons \\ 7 Class \\ Practical work. Then he moved in the catalog tree to the level above, descended into the presentation subdirectory and deleted the Introduction file from it. PPT. What is the full file name that teacher deleted? Decision. The user worked with the catalog: Lessons Grade 7. D: Practical work. Having risen to one level up. It was in the directory: descending one level down. It was in the presentation directory: Presentations. In the presentation directory, he deleted the Introduction file. Full name of the remote file: D: \\ Lessons \\ 7 Class \\ Presentation \\ Introduction. PPT.

Working with files creates files using programming and application software. Basic operations with files: copying (a copy of a file in another directory or another carrier is created); Movement (file transfer to another directory or another media, the source file is destroyed); Rename (renaming the file name itself); Removal (in the source directory the object is destroyed). Àï è ñ ô Àéëèè êê è. s WF. When searching for a file, you can use the file name mask - a sequence of letters, numbers and other valid characters in file names, including:? (question mark) - means exactly one arbitrary symbol; * (asterisk) - means any (including an empty) sequence of arbitrary length characters. For example, on mask N? . * Files with arbitrary extensions and two-letter names starting with the letter "N" will be found.

The most important file is the named area of \u200b\u200bexternal memory. The file name, consists of two parts separated by the point: the file name itself and the extension itself. The directory is the named set of files and subdirectories (nested directories). The top-level directory is called the root directory. The file structure of the disk is a set of files on disk and interconnections between them. File structures are simple and multi-level (hierarchical). The path to the file is the names of all directories from the root to the one in which the file is directly. The consistently recorded path to the file and the file name make up the full file name. The full name of the file is unique.

Questions and tasks What is the file? What are the basic rules for naming files in the operating system installed on computers in your class? Name the names of your known programs that open files with the following extensions: TXT, DOC, BMP, RTF, ARJ. Name the logical names of the external memory devices on the computer to which you have access. What is the catalog? What catalog is called root? How can files in external memory be organized? What is the name of the graphic image of the hierarchical file structure? What is the path to the file on the disk? What is the full file name? List the basic operations performed with files. Pushkin file. Doc is stored on a rigid disk in the poetry catalog, which is a directory literature subdirectory. The table shows the 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 catalog: D: \\ Lessons \\ Informatics \\ Practical works. He rose into two levels up, then descended into the algebra subdirector and created the QuAR file in it. TXT. What is the full name of the file that Sasha created? The user worked with the catalog: D: \\ Documents \\ photo \\ 2011 \\ spring. At first he rose to three levels up, then descended into the exam catalog and then descended into the computer science catalog. Specify the full path for the catalog in which the user was. 1) D: \\ Documents \\ Pictures \\ Informatics 2) D: \\ Documents \\ Informatics \\ Exam 3) D: \\ Documents \\ Exam \\ Informatics 4) D: \\ Documents \\ Pictures \\ 2011 \\ Spring \\ Exam \\ Informatics List Inex Select ( Mark the checkmark) 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 name, select (Mark the checkbox) those that do not satisfy the mask? L * CK *. *? : _ click. TXT Black. PPT LO 3 CK. Sts clock. TT blink. UTA AppLock. Stu Blocker. HTM ELPACK. Ty Blocker. HTML. Specify which of the files specified below satisfy the mask? ESE * IE. ? T * 1. Seseie. TTX 2. Esenie. TTX 3. ESEIE. XT 4. SESENIE. TXT A B C D E literature C: Pushkin \\. Doc Poetry

The support summary of the file is the named external memory area. Each external memory connected to the computer has a logical name (A: B: C: D: E: F: ...) File search File file name Address File name Disc: \\ path Name. Expansion simple hierarchical file structure file file type extensions System file DRV, SYS text file TXT, RTF, DOCX, ODT graphic file BMP, GIF, JPG, TIF, PNG, PDS sound file WAV, MP 3, MIDI, KAR, OGG video file AVI, MPEG Archive Zip, RAR Electronic Table XLS, ODS

Keywords:

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

2.4.1. Logical names of external memory devices

Multiple external memory devices can be connected to each computer. The main device of the external memory of the PC is a hard disk. If a hard disk has a sufficiently large container, then it is divided into several logical partitions.

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

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

Each external memory device connected to the computer, as well as each logic section of the hard disk, has a logical name.

In the Windows operating system, the logical names of the external memory devices consisting of one Latin letters and a colon mark are taken:

• for floppy disks (floppy disks) - A: and in:;
• for hard drives and their logical partitions - from:, B:, E: IT. d.;
• for optical drives - names following alphabetics after the name of the last one available on the computer of a hard disk or partition of a hard disk (for example, F :);
• for the flash memory connected to the computer - the name following the last name of the optical drive (for example, G :).

Other rules for naming disks and their sections are adopted in the Linux operating system. For example:

• logical sections belonging to the first rigid disk receive the names of HDAL, HDA2, etc.;
• logical sections belonging to the second rigid disk receive the names of HDBL, HDB2, etc.

2.4.2. File

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

The file system is part of the OS, which defines the method of organizing, storing and naming files on media information.

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

The file name, as a rule, consists of two parts separated by the point: the file name itself and the extension itself. Actually the file name gives the user. It is recommended to do this in meaningful, reflecting the file content name, although the user can specify an arbitrary set of characters as a name. The name extension is usually specified by the program automatically when creating a file. Extensions are not mandatory, but they are widely used. The extension allows the user without opening the file, to determine its type - what type of information (program, text, drawing, etc.) is contained in it. The extension allows the operating system to automatically open the file.

In modern operating systems, the file name may include up to 255 characters, and the letters of national alphabets and spaces can be used in it. The file name extension is recorded after the point and usually contains 3-4 characters.

In Windows OS in the file name, it is prohibited to use the following symbols: \\, /,:, *, ",", |. In Linux these characters, except /, are allowed, although it should be used with caution, as some of them may have a special Meaning, as well as for considerations of compatibility with other OS.

The Linux operating system, unlike Windows, distinguishes lowercase and uppercase letters in the file name: for example, file.txt, file.txt and file.txt is in Linux three different files.

The table shows the most common types of file types and their expansion:

In Linux, allocate the following types of files:

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

2.4.3. Catalogs

On each computer media (hard, optical disk or flash memory), a large number of files can be stored. For convenience of finding information, files on certain features are combined into groups called directories or folders.

The directory also gets its own name. He himself can be part of another, external in relation to the catalog. Each directory may contain multiple files and nested directories.

The top-level directory is called the root directory.

In Windows, any information carrier has a root directory that is created by the operating system without user participation. The root directories add to the logical name of the corresponding external memory device of the "\\" sign (reverse slash) are indicated: A: \\, C: \\, D: \\, E: \\, etc.

In Linux, rigid drive directories or their logical partitions do not belong to the top level of the file system (are not root directories). They are "mounted" in the MNT directory. Other external memory devices (flexible, optical and flash drives) are "mounted" to the Media catalog. MNT and Media catalogs, in turn, are "mounted" into a single root directory, which is indicated by the "/" sign (direct slash).

2.4.4. File disk file

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

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

Fig. 2.8.
Simple file structure

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

Fig. 2.9.
Hierarchical file structure

User, combining at its own discretioning files to directories, it is possible to create a convenient storage system for itself. For example, you can create separate directories for storing text documents, digital photos, melodies, etc.; In the catalog for photos, combine photos by year, events, accessories, etc. Knowing how the catalog belongs to the file, significantly speeds up its search.

The graphic image of the hierarchical file structure is called wood. In Windows, catalogs on different disks can form several separate trees; In Linux, catalogs are combined into one tree, common to all disks (Fig. 2.10). Vidoid hierarchical structures can be depicted vertically and horizontally.

Fig. 2.10.
Directory tree in Linux OS

2.4.5. Full file name

To refer to the desired file stored on some 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.

In the Windows operating system, the path to the file begins with the logical name of the external memory device; After the name of each subdirectory, the reverse slash is put. In the Linux operating system, the path to the file begins with the name of the single root directory; After the name of each subdirector, the straight slash is put.

The consistently recorded path to the file and the file name make up the full file name. There can be no two files that have the same full names.

An example of a full file name in Windows:

E: \\ Images \\ Photo \\ Katun.jpeg

An example of a full file name in Linux OS:

/ Home / Methody / Text

Task 1.. The user worked with the C: \\ physics catalog \\ kinematics. At first he rose to one level up, then rose once again to one level up and then went down to the examination directory in which the informatics file is located. What is the path to this file?

Decision.

The user worked with the C: \\ physics catalog \\ kinematics. Rising one level up, the user turned out to be in the catalog with: \\ physics \\ tasks. Rising another level up, the user was in the catalog with: \\ physics. After that, the user went down to the Exam directory where the file is located. The full path to the file is: C: \\ Physics / Exam

Task 2.. The teacher worked in the catalog D: \\ Lessons \\ 8 Class \\ Practical work. Then he moved to the catalogs to the level above, went down to the presentation subdirectory and deleted the Introduction file from it. What is the full file name that teacher deleted? Decision.

The teacher worked with the catalog D: \\ Lessons \\ 8 Class \\ Practical work. Rising one level, it was in the d: \\ lessons \\ 8 class. After that, the teacher descended into the presentation directory, the path to the files of which has the form: D: \\ Lessons \\ 8 Class \\ Presensence. In this directory, he deleted the Introduction file .PPT, the full name of which D: \\ Lessons \\ 8 Class \\ Presentations \\ BVENE.PPT

2.4.6. Working with files

Files are created using programming and application software systems.

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

• copying (a copy of a file in another directory or another carrier is created;
• movement (file transfer to another directory or another media, the source file is destroyed);
• rename (renaming the file name itself);
• removal (in the source directory the object is destroyed).

When searching for a file whose name is known inaccurately, it is convenient to use the file name mask. The mask is a sequence of letters, numbers and other valid characters in file names, among which the following characters may also occur: "?" (question mark) - means exactly one arbitrary symbol; "*" (Asterisk) means any (including empty) sequence of arbitrary length characters. For example, on a N * .txt mask, all files with the TXT extension will be found, the names of which begin with the letter "P", including the N.Txt file. Mask P? * Files with arbitrary extensions and two-letter names starting with the letter "N" will be found.

The most important thing

The main device of the external memory of the PC is a hard disk. If a hard disk has a sufficiently large container, then it is divided into several logical partitions. Each external memory device connected to the computer, as well as each logic section of the hard disk, has logical names.

The file is the named area of \u200b\u200bexternal memory. The file name, as a rule, consists of two parts separated by the point: the file name itself and the extension itself.

The directory is the named set of files and subdirectories (nested directories). The top-level directory is called the root directory.

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

The path to the file is the names of all directories from the root to the one in which the file is directly. The consistently recorded path to the file and the file name make up the full file name. The full name of the file is unique.

Questions and tasks

"File archive" - \u200b\u200bserver file system. FTP client. File-FTP file sharing program. Server file system2. User. FTP protocol. Server Interpreter1. Server data transfer program2. Data. Data channel. Using archives. The server usually starts at the time of downloading the computer. Data exchange in FTP passes through the TCP channel.

"Image in Word" - work with pictures in a text editor Microsoft Word. Selection of lines, arrows, figures. Hello! Reset pattern settings. Consider the drawing panel menu. Actions with drawings. Changing brightness. The task. Two buttons on the drawing panel will help add a picture, add a picture. To create an object shade.

"Image" - compression of images. Image presentation. Coding into binary values \u200b\u200bomit. Exercises. Next, check the neighboring areas for homogeneity and merge where possible. Search by image database. Then restore (decode) image. Structures databases for images. Approximate image database architecture.

"The cylinder is called the body" - the height of the cylinder is 8 m, the radius of the base is 5 m. The cylinder is crossed by the plane so that a square turned out in the section. Solution: Project "Mathematics in the profession" Cook, confectioner ". Task number 3. Cylinder. The correct hexagonal prism is inscribed in the cylinder. Find the length (h) perpendicular ok. 4) under the condition Av \u003d A "in" \u003d M "\u003d 8. In the rectangular triangle of AOK Katts AK \u003d 4. Then by the Pythagore Theorem H \u003d OK \u003d \u003d 3 m.

"Creating graphic images" - the autofigur button is designed for drawing various geometric shapes. Autofigurians. Comparative characteristics of raster and vector graphics. Position of the graphic image in the text. Insert pattern from file. Inserting pictures from the Microsoft Office collection. Insert? Picture? From the file. Insert the drawing from the collection to the text.

"Computer graphics" - raster graphics. Large data volumes. Each point of the screen can have only two states - "black" or "white". Formats of raster graphics files. Pixel is the smallest element of the bitmap. Computer graphics. Color images can have a different color depth (bit per point 4, 8, 16, 24).