The window title for an MS-DOS – based application, which is displayed when the application runs in a window, identifies the application and its operating state. The operating system sets the title when an application first starts, but the application can change portions of the title to better communicate its state to the user.
The window title consists of three strings: a virtual machine state, a virtual machine title, and an application title. The system creates the window title by concatenating the three strings, separating the strings with a system-defined separator, typically a hyphen.
The virtual machine state, which can be set by the operating system only, identifies whether the virtual machine is inactive or whether the user is carrying out tasks, such as cut and paste operations. The state is frequently an empty string. The virtual machine title and the application title, which can be set by an application, identify the application and the current document or activity of the application, respectively.
By default, the operating system sets the virtual machine title to the title stored in the corresponding .PIF file or to a title specified by the shell. You can determine the current virtual machine title by using the Get Virtual Machine Title function. You can change the title by using the Set Virtual Machine Title function.
The system typically sets the application title to the name of the application, so the virtual machine title and application title are frequently the same when the application first starts. Many applications change this title to the name of the current document or to an empty string if there is no current document. You can determine the current application title by using the Get Application Title function. You can change the title by using the Set Application Title function.
If you set the virtual machine title or application title, the length of the individual titles must not exceed 30 and 80 characters, respectively.
You can call the window title functions at any time. Furthermore, you can call these functions regardless of whether your application is running with the Windows 95 or MS-DOS operating system. However, not all operating systems support these calls. The functions are not supported if a call to a function leaves the AX register unchanged.