What is a graphic representation of a hierarchical structure called? The graphical representation of a hierarchical file structure is called. Full file name

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

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

Logical names of external memory devices Each external memory device connected to a computer has a logical name. In Windows OS, logical names of external memory devices are accepted, consisting of one Latin letter and a colon: 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 the alphabetical order after the name of the last hard drive or hard drive partition on the computer DVD RW drive (E:) A (A:) for flash memory connected to the computer - the name following last name of the optical drive (for example, F:) Removable disk (F:) 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 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 OS that determines the way 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 creating the file. File type Examples of extensions 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 OS, root directories are indicated by adding the sign “\” to the logical name of the corresponding external memory device (A: \, C: \, D: \, E: \) In Linux OS, hard drive directories are not root directories. They are "mounted" into 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.

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

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

Disk file structure In Windows, directories on different disks can form several separate trees. In Linux, directories are combined into one tree, common to all disks. Tree-like hierarchical structures can be depicted 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. In Windows OS, the file path begins with the logical name of the external memory device; After the name of each subdirectory there is a backslash: E: \images\photos\Katun. jpeg In Linux OS, the file path begins with the name of the single root directory; The name of each subdirectory is followed by a forward slash: /home/methody/text The path to the file and the file name written down in sequence form the full name of the file. No two files can have the same full name.

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

Task 2 The teacher worked in directory D: \Lessons\7th grade\Practical work. Then I went up one level in the directory tree, went down to the Presentations 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 catalogue: Lessons 7th grade. D: Practical work. Having gone up one level, he found himself in the directory: Having gone down one level, he found himself in the Presentations directory: Presentations. In the Presentations directory, he deleted the file Introduction. Full name of the 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 moved to another directory or to another medium, the original file is destroyed); renaming (the actual file name is renamed); deletion (the object in the source directory is destroyed). This is how it works. s wf. When searching for a file, you can use a file name mask - a sequence of letters, numbers and other characters allowed in file names, including: ? (question mark) - means exactly one arbitrary character; * (asterisk) - means any (including empty) sequence of characters of arbitrary length. For example, by mask n? . * files with arbitrary extensions and two-letter names starting with the letter “n” will be found.

The most important thing is that 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 the disk and the relationships between them. File structures can be simple or 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 located. The file path and file name written down in sequence form the full file name. The full file name 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 classroom? Name 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 memory devices on the computer that you have access to? What is a directory? Which directory is called the root directory? How can files in external memory be organized? What is a graphical representation of a hierarchical file structure called? What is the path to a file on disk? What is the full file name? List the main operations performed with files. File Pushkin. doc is stored on your 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 a sequence of letters without spaces or commas). Sasha worked with the directory: D: \ LESSONS \ COMPUTER SCIENCE \ PRACTICAL WORK. He 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\PHOTOS\2011\SPRING. First, he went up three levels, then went down to the EXAMINATION directory, and after that he went down to the COMPUTER SCIENCE directory. Specify the full path for the directory the user is in. 1). 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 (check) 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. Please indicate which of the following file names matches the mask? ese*ie. ? t* 1. seseie. ttx 2. esenie. ttx 3. eseie. xt 4. sesenie. txt A B C D E E LITERATURE C: Pushkin \. doc POETRY

Background Note A file is a named area of external memory. Each external memory 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 File structure of the disk File type Examples of 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 Spreadsheet xls, ods

One computer can have several disk drives - devices for working with disks. Each drive is given a one-letter name (followed by a colon), for example A:, B:, C:. Often on personal computers, a large-capacity disk built into the system unit (called a hard drive) is divided into partitions. Each of these partitions is called a logical disk, and it is given the name C:, D:, E:, etc. The names A: and B: usually refer to small-capacity removable disks - floppy disks (floppy disks). They can also be considered as 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 determines the location of the file.

3. Disk file structure

The entire collection of files on the disk and the relationships between them is called the file structure. Different operating systems may support different file structure organizations. 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 disk, you only need to specify the file name. For example, if the tetris.exe file 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 an analogy with the traditional “paper” method of storing information. In this analogy, a file is represented 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 think of a directory as a folder into which you can attach many documents, i.e. files. The directory also gets its own name (think of it on the cover of a folder).

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

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

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

In Fig. 2.1 directory names are written in capital letters, and file names are written in lowercase letters. 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, etc. In the tree, the root directory is usually represented by a symbol.

Rice. 3.1. Example of a hierarchical file structure

“File archive” - Server file system. Ftp client. File sharing 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. Data exchange in FTP takes place over a TCP channel.

“Image in Word” - Working with pictures in the Microsoft Word text editor. Selecting lines, arrows, shapes. Hello! Reset picture settings. Examine the Drawing panel menu. Actions with drawings. Change brightness. Exercise. Two buttons on the Drawing panel will help you add a picture or add a drawing. To create a shadow of an object.

"Image" - Image compression. Presentation of images. Omit encoding to binary values. Exercises. Next, check adjacent areas for uniformity and drain where possible. Search the image database. Then restore (decode) the image. Database structures for images. Sample database architecture for images.

“A body is called a cylinder” - The height of the cylinder is 8 m, the radius of the base is 5 m. The cylinder is intersected by a plane so that the section turns out to be a square. Solution: Project “Mathematics in the profession “Cook, confectioner”. Problem No. 3. Cylinder. A regular hexagonal prism is inscribed in a cylinder. Let's find the length (h) of the perpendicular OK. 4) By condition AB = A"B" = M" = 8. In a right triangle AOK the leg AK = 4. Then, by the Pythagorean theorem, h = OK = = = 3 m.

“Creating graphic images” - The AutoShape button is designed for drawing various geometric shapes. Autoshapes. Comparative characteristics of raster and vector graphics. The position of the graphic image in the text. Inserting a picture from a file. Insert a picture from the Microsoft Office collection. Insert? Drawing? From file. Insert a picture from the collection into the text.

“Computer graphics” - Raster graphics. Large volumes of data. Each point on the screen can have only two states - “black” or “white”. Raster graphics file formats. Pixel is the smallest element of a raster image. Computer graphics. Color images can have different color depths (bits per dot 4, 8, 16, 24).

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

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

Having multiple logical partitions on one hard drive 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 drive in different logical partitions;
Maintenance of one logical partition does not affect other partitions.

Each external memory device connected to the computer, as well as each logical partition of the hard drive, has a logical name.

The Windows operating system accepts logical names for external memory devices, consisting of one Latin letter and a colon:

for floppy disk drives (floppy disks) - A: and B:;
for hard drives and their logical partitions - C:, B:, E: it. d.;
for optical drives - names that follow the alphabetical order after the name of the last hard drive or hard drive partition on the computer (for example, F:);
for flash memory connected to a 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 external memory of the computer in the form of files.

The file system is a part of the OS that determines the way 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 specify an arbitrary set of characters as the name. The name extension is usually set automatically by the program when creating the file. Extensions are not required, 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.) 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 a period and usually contains 3-4 characters.

On Windows, the following characters are prohibited in file names: \, /, :, *, ?, ", |. 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 file types are distinguished in Linux OS:

regular 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 and optical drives, printer, sound speakers, etc.).

2.4.3. Catalogs

Each computer storage medium (hard drive, optical disk, or flash memory) can store a large number of files. To make it easier to find information, files are grouped according to certain characteristics into groups called directories or folders.

The directory also gets its own name. It itself can 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.

In Windows OS, any information carrier has a root directory, which is created by the operating system without user intervention. Root directories are designated by adding the “\” (backslash) sign 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" into 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 can be simple or multi-level (hierarchical).

Simple file structures can be used for disks with a small (up to several dozen) number of files. In this case, the disk table of contents 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) of files. Hierarchy is the arrangement of parts (elements) of a whole in order from highest to lowest. The initial (root) directory contains first-level files and subdirectories. Each of the first-level directories can contain files and subdirectories of the second level, etc. (Fig. 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, by combining files into directories at his own discretion, has the opportunity to create a convenient information storage system. For example, you can create separate directories for storing text documents, digital photos, ringtones, etc.; in the photo catalog, combine photos by year, event, affiliation, etc. Knowing which directory a file belongs to makes searching for it much faster.

A graphical representation of a hierarchical file structure is called a tree. In Windows, directories on different drives can form several separate trees; in Linux, directories are combined into one tree, common to all disks (Fig. 2.10). Tree-like hierarchical structures can be depicted 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 itself is located.

In the Windows operating system, the file path begins with the logical name of the external memory device; Each subdirectory name is followed by a backslash. In the Linux operating system, the file path begins with the name of the single root directory; Each subdirectory name is followed by a forward slash.

The file path and file name written down in sequence form the full file name. No two files can have the same full name.

Example of a full file name in Windows OS:

E:\images\photos\Katun.jpeg

Example of a fully qualified file name in Linux OS:

/home/method/text

Problem 1. The user worked with the directory C:\Physics\Tasks\Kinematics. First, he went up one level, then he went up one level again, and after that he went down to the Exam directory, in which the Informatics.doc file is located. What is the path to this file?

Solution.

The user worked with the directory C:\Physics\Tasks\Kinematics. Having gone up one level, the user found himself in the C:\Physics\Tasks directory. Having gone up one more level, the user found himself in the C:\Physics directory. After this, the user went down to the Exam directory, where the file is located. The full path to the file is: C:\Physics\Exam

Problem 2. The teacher worked in the directory D:\Lessons\8th grade\Practical work. Then I went up one level in the directory tree, went down to the Presentations 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 gone up one level, it ended up in the D:\Lessons\8th grade directory. After this, the teacher went down to the Presentations directory, the path to the files of which looks like: D:\Lessons\8th grade\Presentations. In this directory, he deleted the file Introduction.ppt, the full name of which is D:\Lessons\8th grade\Presentations\Introduction.ppt

2.4,6. Working with files

Files are created using programming systems and application software.

When working on files on a computer, 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 moved to another directory or to another medium, the original file is destroyed);
renaming (the actual file name is renamed);
deletion (the object in the source directory is destroyed).

When searching for a file whose name is not known exactly, it is convenient to use a 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 appear: “?” (question mark) - means exactly one arbitrary character; “*” (asterisk) - means any (including empty) sequence of characters of arbitrary length. For example, using the mask n*.txt, all files with the txt extension whose names begin with the letter “p” will be found, including the file n.txt. Using the mask p?.*, files with arbitrary extensions and two-letter names starting with the letter “n” will be found.

The most important

The main external memory device of a PC is the hard drive. If the hard drive has a sufficiently large capacity, then it is divided into several logical partitions. Each external memory device connected to the computer, as well as each logical partition of the hard drive, 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 the disk and the relationships between them. File structures can be simple or multi-level (hierarchical).

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