What exactly is a "Console"?

Question

I am trying to writing a console application. It has its original console, let's name it console A. And I want this application to do the following things via C#:

1. Open another console B in another thread, then get input from A and output it to B;
2. type a command in A, such as dir, and show the output in B;

while doing the above things (still not done yet. X_X ), I find myself lack a through understanding of what a console window is, and how it is assigned to a console application, especially the very first console when my console application starts to run. Could some one shed some light on me?

Is console window physically a memory area in the video memory? Or something else? Could different threads within the same process have different console of its own for its own I/O?

Many thanks...

Hi, guys, now I am using one console application to start another console application in a new process. Thus I can have 2 consoles output at the same time.

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My understanding now is that, for Windows OS, a console is a special window, and it's a system resource that OS assigned to the application without-a-UI as a necessary user interface. Windows OS handles the wiring between the system-prepared console window with our UI-less application.

Answer 1

A console application has only one window. It does not have window management functions in order to spawn child "consoles".

You can start additional console applications, but these are separate entities.

Answer 2

In Windows terms, a Console is a textual GUI window that you see when you run "cmd.exe". It allows you to write text to, and read text from, a window without the window having any other UI chrome such as toolbars, menus, tabs, etc,..

To get started you'll want to load Visual Studio, create a new project and choose "Console Application". Change the boilerplate code that Visual Studio produces to:

using System;
using System.Text;

namespace MyConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Hello, world!");
            Console.ReadKey();
        }
    }
}

When you run your application, a console window will open with the text "Hello, world!" and it'll stay open until you press a key. That is a console application.

Is console window physically a memory area in the video memory? Or something else?

It's not physically a memory area in video memory, it's "something else". The Wikipedia Win32 console page gives a fairly robust descrption of the ins and outs.

Answer 3

No. It's a windows GUI subsystem. In WinAPI there are functions to work with console: http://msdn.microsoft.com/en-us/library/ms682073%28VS.85%29.aspx

Answer 4

A (OS) console is a process (containg one or more threads of executions, all of them sharing the same memory space), and this process has:

• standard input (a stream of input bytes), what you key in
• standard output (a stream of output bytes), what the program prints
• standard error (a stream of output bytes), what the program prints when it's complaining about something

So if you want to create another console (from .Net) and link the input/outputs I understand you have to create a process (executing "cmd.exe" by example).

I don't know the API of .Net for process manipulation but if it's like Java you can hook up stdin, out and err so you can play with your created process from the original one.

Answer 5

A windows application can have one console, or no console, it can't have more than one. See the documentation for AllocConsole. The console is basically an emulation of the 'pre-Windows' days when there would literally be a 'control console' i.e. a keyboard and screen attached to a mainframe computer. To do what you want you could spawn another process with its own console and communicate between the two, or make a GUI application which looks like a console window.