USER INTERACTION WITH OS

One of the three most important functions of an OS is its user interface. It is thanks to him that it becomes possible to run programs, control their execution and provide file maintenance. These same means of interacting with the operating system include many other means and functions.

By now, two fundamentally different interface systems have developed (in translation - interaction with the user). The first system is called command interface or command line interface... It allows the user to control the launch and execution of programs by specifying control texts from the text console, i.e. teams. Such a system was formed in the early 70s of the XX century and was most fully developed within the framework of the Unix operating system. Note that control with the help of special texts is very close in features to ordinary programming in high-level languages, and therefore the command interface is easily mastered by programmers, for non-professional users this approach can turn out to be as difficult as learning to program.

The second of the mentioned interface systems is graphical. It was developed by PARC (Palo Alto Research Center of Xerox) in the late 70s of the XX century, but was widely used first in Apple operating systems (MacOS) in the mid 80s, and then in operating shells, and later in operating systems from Microsoft. It is well known to the wide masses of non-professional users for the graphical shells MS Windows 3.1, Windows 9x, Windows NT and their later modifications.

Controlling a computer using a graphical interface is as much about a command line interface as watching comics (storytelling in pictures) is about reading fiction. Undoubtedly, both first options are easier for an inattentive or illiterate person, as well as for a person who is not used to bothering himself. At the same time, the number of users of both comics and the graphical interface exceeds the number of users of strict texts by an order of magnitude, if not by orders of magnitude.

Management with the help of a graphical interface is psychologically many times easier and requires significantly less volitional efforts, attention and memorized information. Practically in the graphical interface, the necessary information is almost always present directly on the screen, where it is proposed to make one of the possible choices. But at the same time, complex configuration requires many dialog boxes, and in many cases the overall picture of the configuration turns out to be hard to see. In practice, this approach is capable of solving only a small number of typical configuration tasks, but it has neither depth nor versatility. Ideally, the graphical interface is very close to the programming language Cobol, so beloved by the Americans, which is designed to solve economic problems and allows you to write algorithms not using specialized and rather abstract operators, but using almost ordinary English phrases. In particular, arithmetic operations in Cobol are written not by mathematical symbols, but by the English words add, subtract, multiply. A layman is very much comforted by this style, but a professional is annoyed by the lack of compactness and clarity in informational control structures.

Despite the widespread use of a graphical interface in an OS such as Windows, internal communication between the components of the operating system itself inevitably has the character of control texts, in particular, machine commands and text calls of system functions. The fundamental complexity of the task within the program of the analogue of influencing the graphical interface forcibly leaves the command line interface in some background, not visible to non-professional users. Therefore, almost all attention in this chapter will be focused on the command line interface, and we will not consider the capabilities of the graphical interface, referring for its study to many guides on the surface management of specific operating systems.

An interface is an intermediary that transforms the control of a computer's operation into a user-friendly form.

Before getting familiar with the interface elements, let's take a look at the controls in Windows. It is generally accepted that the keyboard and mouse are the input devices for the PC. This is not entirely correct, since these elements are used not only for input, but also for controlling elements of the Windows OS.

The mouse is the main control element of the Windows operating system. It contains, as a rule, two control buttons: left and right, and a scroll wheel. The left key is multifunctional, with its help you can perform a number of operations: launching programs, selecting objects, "dragging" objects, etc. The right key is used to launch the Context Menu. The scroll wheel is used to move within the document. In laptops, a "touchpad" is provided as a replacement for a mouse - a special, touch-sensitive platform.

The keyboard is mainly used to enter text in documents, however, it can also act as a control element using controls and so-called "hot" keys. The keys are intended for their use. Ctrl and Alt.

The Windows OS interface consists of the desktop, the taskbar, the system of icons or shortcuts, and the user menu.

Rice. 2.2 Windows 7 desktop.

The desktop is the image on the monitor screen that appears after the PC boots up, on which the main control elements are located. The main ones are icons. Various objects are displayed with the help of icons: launching programs, documents, disks, folders, graphic and video files, etc. Moreover, objects can be represented both as objects themselves and as links to objects. In the second case, the icons are called labels, and have a pointer in the form of a small arrow in the lower left corner. The number and location of icons on the desktop is individual for each user. Working with icons is controlled by the mouse.

The taskbar is located at the bottom of the desktop and consists of a "notification area" on the right side, a "taskbar" on the left, and the "Start" button on the far left.

The "notification area" contains various information necessary for the current work on the computer. The "taskbar" displays running applications. The Start button contains the user menu.

Working with these elements is carried out using the mouse pointer.

For example, to view documents currently open in Word, you need to place the mouse pointer over the Word icon on the taskbar. All open documents will be displayed on the screen as separate windows.

Rice. 2.3. Taskbar with open documents.

The user menu, launched by left-clicking on the "Start" icon, is the main component of Windows. It contains the basic elements of working with a computer.

Fig 2.4. User's menu.

The menu consists of two columns.

The left side contains icons for the most frequently used programs. The arrows to the right of programs show a list of files recently opened in that program. “All programs” is a list of all programs installed on the computer. At the very bottom there is a search line that can easily find any file or folder on your computer by keyword.

· "Computer" opens the file manager;

· "Control Panel" - Windows settings;

· "Programs by default" associate a document type with the corresponding application;

· "Help and Support" - a detailed electronic textbook on Windows;

· "Shutdown" is used when the computer is turned off.

The presentation of information in Windows is built in the form of windows.

Rice. 2.5. "Computer" folder window.

The window consists of the following elements:

· Title of the window, which indicates the open program;

Window control buttons (minimize, expand to full screen, close);

· user's menu;

· Toolbar;

· Informational part.

The window can be arbitrarily positioned on the desktop, and the size of the window can be changed. When working with several programs, you can open multiple windows at the same time. This mode of operation is called multi-window. The transition from one window to another is carried out using the mouse pointer.

The easiest way to customize the interface is by calling the context menu by right-clicking on a free area of ​​the desktop. On the command "personalization" a window opens with various elements of setting the Windows interface.

Rice. 2.6. Interface settings.

Windows appearance includes the following elements: desktop background, cursor, color scheme, system sounds, etc. Any of these elements can be changed separately, but the easiest way is to select a set of settings in the form themes... Microsoft offers a wide variety of themes, including high-contrast layouts for the visually impaired.

One of the main parameters of the image on the monitor screen is permission screen. It is set in the form of specifying the number of dots horizontally and vertically in the settings of the "Screen" menu item. By default, when you install Windows on your computer, the most reasonable layout for the display is installed. Despite the possibility of self-adjusting the image, it is recommended to change them only when replacing the monitor, as monitor settings affect the image quality.

Another design element is gadgets- gadgets. They are installed using the "gadgets" item of the context menu.

Rice. 2.7. Gadgets.

The gadget can be placed anywhere on the desktop and installed on top of all windows. In this case, it is useful to make the gadget translucent so that it does not interfere with your work. If you wish, you can add to your collection of gadgets on the Internet.

Most users easily operate with terms, not really thinking about their meaning. Even the fact that one word is used in different contexts is no longer surprising, although this aspect should be given attention. What is an interface - the interaction between people and technology, which nowadays manifests itself in many areas.

Interface - what is it?

Often this word flickers in computer terminology, although a frequent visitor and in a completely different context. In engineering psychology, the term is explained as different methods of communication between the user and office equipment. The designation "interface" came from the British, which means "between persons". In the field of Internet technologies, this term encompasses unified communication systems that guarantee the exchange of data between objects. The most common term is "user interface" - a set of methods that help a person to operate equipment.

Experts distinguish two types:

1. Boolean interface type. A set of established algorithms and agreements for the exchange of data between elements.
2. The physical type of the interface. The connection of automatic, physiological and multifunctional data, with the support of which the connection is realized.

This term has its own classification in defining the set of software and hardware that form the interconnection of devices:

1. Intra-machine interface- connection of wires, interfacing circuits with PC elements and signal transmission algorithms. Distinguish between simply connected and multiply connected.
2. Front end- the concept of interconnection of a PC with remote devices. There is a peripheral and network interface.

What is an intuitive interface?

What is a user interface is a view where one position is represented by a person, and the opposite is a device. The phrase is often mentioned by IT specialists, but already in the interpretation of a set of methods and laws of system interaction:

• TV menu and remote control;
• clock screen and its settings;
• instrument board and control levers.

If we consider the system interface as a communication between the user and office equipment, then it can be characterized as a dialogue. The user sends requests for data to the office equipment or asks for help, and in return receives the necessary comments or a guide to action. A usability interface is a characteristic of how convenient, ergonomic, and how much effort it takes to get the best possible result.

What is a site interface?

If the interface is a combination of hardware and software that guarantees the interaction of devices, then the Internet site is a built-in mechanism for the user to communicate with the system. The user can:

• use the services;
• make orders and applications;
• fill out questionnaires.

What is a user-friendly interface? The term means that you like the appearance of the resource, the mechanism of its operation is clear, the system clearly gives recommendations. Basic requirements for the site interface:

• naturalness;
• consistency;
• direct access to the help system;
• consistency.

What is an interface in a computer?

The user interface of the application also plays a very important role, because the program itself is assessed by these indicators. The developers note the following basic provisions:

1. A reference to the device for which the application is being made.
2. The icon must reflect the main idea.
3. The touch area of ​​the touch screen must have a significant error.

Operating system interface

There is also such a term as "operating system interface" - a set of tools that transmit control commands. The following is a breakdown into subspecies:

1. Command line interface- the type of text communication between the user and the PC, when phrases are typed on the keyboard manually.
2. Programming interface- requests are passed by programs. A series of OS utilities has been developed, from which the user selects the one he needs.

What is the program interface?

The program interface is a set of guiding components of the program that help the user to perform a number of actions: keys and windows on the monitor. To see a movie, they use a media player program, and the image and sound are already regulated by buttons and sliders. The system interface guarantees the necessary data in programs; there are two types of interface pages:

1. Queries where a menu-driven approach is implemented.
2. Search results.

Game interface

What is a graphical interface is a type of user interface in which menus and buttons are presented on the screen in the form of graphical images. It provides an opportunity for fans of online games to control heroes and communicate with other players. Thanks to this program, users enter any actions of the figures using a mouse or keyboard. This view was created for the convenience of technicians, but over time became the invention that shaped the PC market.

There are several fundamental concepts in the field of information technology. One of them is "interface". Note that it can be interpreted from different points of view. The previous chapter described the concept of "System Call Interface". If you look for such a term in Yandex Dictionaries, you will receive more than a dozen definitions of the term, most of which are given in combination with other terms, for example: "Data transfer interface", "Programming interface", "Application interface". In the dictionary "Natural Sciences" on GLOSSARY .RU the following definition of a fundamental concept is given.

An interface in the broadest sense is a standards-defined boundary between interacting independent objects. The interface defines the parameters, procedures and characteristics of the interaction of objects.

In the "Publishing Dictionary" there is such a definition of the basic term "interface". This:

1. The system of connections and interaction of computer devices.
2. Means of user interaction with the computer operating system, or user program. A distinction is made between a graphical user interface (interaction with a computer is organized using icons, menus, dialog boxes, etc.) and an intelligent interface (means of interaction between a user and a computer in the user's natural language).

As you can see, this term has two meanings here. But we will briefly focus on the second - the "user interface". On the already mentioned source GLOSSARY .RU it is defined as follows: "The user interface is the elements and components of the program that are capable of influencing the user's interaction with the software, including:

• information display means, displayed information, formats and codes;
• command modes, user interface language;
• data entry devices and technologies;
• dialogues, interactions and transactions between the user and the computer;
• user feedback;
• decision support in a specific subject area;
• the procedure for using the program and its documentation ".

With the development of computing, the methods and means of user interaction with the operating system have changed. The widespread use of digital computers has led to a mode of communication between humans and computers in a special language. At first, during the period of batch processing of tasks, this was realized using special storage media (for example, punched cards on which tasks for a computer were applied). But later, with the widespread use of terminals and keyboards, the command mode of user operation became the main one, in which interaction was based on a system of built-in commands. In the free encyclopedia "Wikipedia" it is defined as follows.

Command line interface (CLI) is a type of text interface (CUI) between a person and a computer, in which instructions to the computer are given mainly by entering text strings (commands) from the keyboard; in UNIX systems, the use of a mouse is possible. Also known as console.

Here is an approximate fragment of the screen that appears in the command line mode (Fig. 4.1).

Rice. 4.1.

The prompt () appears on the left in the line, after which you can type a command, the results of which are displayed further. Here is an example of executing the date command on a Linux system (Fig. 4.2).

Rice. 4.2.

The first operating systems from Microsoft for personal computers IBM PC (they were called MS DOS) also supported the command mode, similar to other systems. The line in which the commands were typed was similar to the ones above. Today, the command mode of operating systems is provided by the emulators cmd.exe (for 32-bit mode) or command. com (for 16-bit mode). In graphical mode of the UNIX / Linux family command line emulated by the Terminal program (xterm).

Note that for computers with the MS DOS operating system, the legendary Norton Commander program has become a successful addition to the implementation of such a user interface. It minimized the actions of typing in the command line, allowing you to operate, first of all, by selecting the appropriate command from the menu. This program also actively uses the function keys of the computer. Wikipedia describes this system as follows:

"Norton Commander (NC) is a popular file manager for DOS, originally developed by American programmer John Socha (some additional components were written in whole or in part by other people: Linda Dudinyak - Commander Mail, viewers; Peter Bradeen - Commander Mail; Keith Ermel, Brian Yoder - Viewers) The software was released by Peter Norton Computing (chaired by Peter Norton), which was later acquired by Symantec Corporation. "

Here is an example of a screenshot of this file manager (Fig. 4.3).

Rice. 4.3.

The popularity of the program was so great that numerous clones appeared that more or less accurately copied Nortonian

By the type of user interface, text (linear), graphic and speech operating systems are distinguished.

User interface called a set of techniques for user interaction with the application. The user interface includes communication between the user and the application and the communication language.

Text OS

Linear operating systems implement a command line interface. The main control device in them is the keyboard. The command is typed on the keyboard and displayed on the display screen. The end of the command is by pressing the Enter key. To work with operating systems that have a textual interface, it is necessary to master the command language of this environment, i.e. a set of commands, the structure of which is determined by the syntax of this language.

The first real operating systems had a text-based interface. It is now also used on users' servers and computers.

Graphics OS

Such operating systems implement an interface based on the interaction of active and passive graphical on-screen controls. The control devices in this case are a keyboard and a mouse. The active control element is the mouse pointer - a graphic object whose movement on the screen is synchronized with the movement of the mouse. Passive controls are graphical application controls (onscreen buttons, icons, radio buttons, checkboxes, dropdowns, menu bars, etc.).

An example of purely graphical operating systems are operating systems of the Windows family. The startup screen of such operating systems is a system object called the desktop. Desktop is a graphical environment on which objects (files and directories) and controls are displayed.

In graphical operating systems, most operations can be performed in many different ways, for example through the menu bar, through the toolbar, through the window system, etc. Since operations are performed on an object, it must first be selected (highlighted).

The basis of the graphical user interface is an organized system of windows and other graphical objects, in the creation of which the developers strive for maximum standardization of all elements and methods of work.

Window is a framed rectangular area on the monitor screen, in which applications, a document, a message are displayed. A window is active if the user is currently working with it. All operations performed in graphical operating systems take place either on the desktop or in a window.

Speech OS

In the case of the SILK interface (from English speech - speech, image - image, language - language, knowledge - knowledge) - on the screen, by a speech command, there is a movement from one search image to another.

It is assumed that when using the public interface, you will not need to understand the menu. Screen images will unambiguously indicate the further path of movement from one search image to another along semantic semantic links.