How to Build Console Applications With No GUI

​Console applications are pure 32-bit Windows programs that run without a graphical interface. When a console application is started, Windows creates a text-mode console window through which the user can interact with the application. These applications typically don't require much user input. All the information a console application needs can be provided through command line parameters.

For students, console applications will simplify learning Pascal and Delphi - after all, all the Pascal introductory examples are just console applications.

New: Console Application

Here's how to quickly build console applications that run without a graphical interface.

If you have a Delphi version newer than 4, than all you have to do is to use the Console Application Wizard. Delphi 5 introduced the console application wizard. You can reach it by pointing to File|New, this opens up a New Items dialog - in the New page select the Console Application. Note that in Delphi 6 the icon that represents a console application looks different. Double click the icon and the wizard will set up a Delphi project ready to be compiled as a console application.

While you could create console mode applications in all 32-bit versions of Delphi, it's not an obvious process. Let's see what you need to do in Delphi versions <=4 to create an "empty" console project. When you start Delphi, a new project with one empty form is created by default. You have to remove this form (a GUI element) and tell Delphi that you want a console mode app. This is what you should do:

1. Select File > New Application.
2. Select Project > Remove From Project.
3. Select Unit1 (Form1) and OK. Delphi will remove the selected unit from the uses clause of the current project.
4. Select Project > View Source.
5. Edit your project source file:
   • Delete all the code inside begin and end.
   • After the uses keyword, replace the Forms unit with SysUtils.
   • Place {$APPTYPE CONSOLE} right under the program statement.

You are now left with a very small program which looks much like a Turbo Pascal program which, if you compile it will produce a very small EXE. Note that a Delphi console program is not a DOS program because it is able to call Windows API functions and also use its own resources. No matter how you have created a skeleton for a console application your editor should look like:

program Project1;
{$APPTYPE CONSOLE}
uses SysUtils;

begin
// Insert user code here
end.

This is nothing more than a "standard" Delphi project file, the one with the .dpr extension.

• The program keyword identifies this unit as a program's main source unit. When we run a project file from the IDE, Delphi uses the name of the Project file for the name of the EXE file that it creates - Delphi gives the project a default name until you save the project with a more meaningful name.
• The $APPTYPE directive controls whether to generate a Win32 console or graphical UI application. The {$APPTYPE CONSOLE} directive (equivalent to the /CC command-line option), tells the compiler to generate a console application.
• The uses keyword, as usual, lists all the units this unit uses (units that are part of a project). As you can see, the SysUtils unit is included by default. Another unit is included too, the System unit, though this is hidden from us.
• In between the begin ... end pair you add your code.