Introduction
Windows-based applications consist of executable files and DLLs. Most applications interact with the user through a graphical user interface (GUI) or a character-mode interface. A running application is known as a process. Each process owns system resources. The threads of a process execute its code. The following topics describe the creation and usage of DLLs, processes, and threads. However, for this session we will only discuss Character-Mode Applications.
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Overview |
Description |
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Character-Mode Applications |
Character-mode applications do not provide their own graphical user interface. Instead, they interact with consoles. |
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Dynamic-Link Libraries |
DLLs are executable modules that contain functions and data. DLLs provide a way to modularize applications so they can be loaded, updated, and reused more easily. |
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Process Status Helper |
The process status helper functions make it easier for you to obtain information about processes and device drivers. |
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Processes and Threads |
A thread is the basic unit to which the operating system allocates processor time. A process is an executing application that consists of one or more threads. |
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Services |
A service is an application that conforms to the interface rules of the Service Control Manager. Services can execute even when no user is logged on. |
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Synchronization |
Threads can use synchronization functions to coordinate access to a resource. |
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Tool Help Library |
The functions provided by the tool help library make it easier for you to obtain information about currently executing applications. |
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Window Stations and Desktops |
A desktop is a securable object contained within a window station. A desktop has a logical display surface and contains user interface objects such as windows, menus, and hooks. Each desktop is associated with a thread and can be used to create and manage windows. |
Character-Mode Applications
In this chapter we will concentrate on the character-mode applications. Consoles manage input and output (I/O) for character-mode applications which are applications that do not provide their own graphical user interface. The console functions enable different levels of access to a console. The high-level console I/O functions enable an application to read from standard input to retrieve keyboard input stored in a console's input buffer. The functions also enable an application to write to standard output or standard error to display text in the console's screen buffer. The high-level functions also support redirection of standard handles and control of console modes for different I/O functionality. The low-level console I/O functions enable applications to receive detailed input about keyboard and mouse events, as well as events involving user interactions with the console window. The low-level functions also enable greater control of output to the screen.
Intro to Character-Mode Applications
Consoles provide high-level support for simple character-mode applications that interact with the user by using functions that read from standard input and write to standard output or standard error. Consoles also provide sophisticated low-level support that gives direct access to a console's screen buffer and that enables applications to receive extended input information (such as mouse input).
Consoles
A console is an interface that provides I/O to character-mode applications. This processor-independent mechanism makes it easy to port existing character-mode applications or to create new character-mode tools and applications. A console consists of an input buffer and one or more screen buffers. The input buffer contains a queue of input records, each of which contains information about an input event. The input queue always includes key-press and key-release events. It can also include mouse events (pointer movements and button presses and releases) and events during which user actions affect the size of the active screen buffer. A screen buffer is a two-dimensional array of character and color data for output in a console window. Any number of processes can share a console. We won’t dive the details for this topic. For more info please find it in MSDN - Character Mode Applications.