https://help.tallysolutions.com/docs/td9rel54/td9/using_output_window/command_tab.htm

Command Tab

The Command Tab comprises of an edit box and allows execution of OS commands. The output of the same is available above the edit box.

To activate Command Window edit box, press Ctrl + E or go to View > Command Window

The following operations can be performed using the command window:

%f replaces character for the current file name.

If GUI based applications need to be launched without blocking Tally Developer, use " start ” prefix.

Special command "?" displays the help.

"cls" command can be used to clear the window.

Up arrow and Down arrow navigate between the recent commands executed in the command window.

Double clicking on an existing executed command line brings that command into the edit box.

Double clicking on a command prompt opens the folder shown in Windows Explorer. Double clicking on any other data lines will copy the line text to clipboard.

Help displays all the OS commands and their descriptions.

Starting an Application

Any application can be started by specifying the command in the command window. Multiple projects and files can be opened by specifying command line parameter using the command window.

Following are a few examples:

To open notepad through command window, type notepad.exe and press Enter .

To open Tally.ERP 9, type tally.exe and press Enter .

Suppose you are working on a TDL project which is under source control and it allows  the command line options like checkin, checkout, and others, then the Command window can be used from Tally.Developer 9.