Tk_MainLoop - loop for events until all windows are deleted
Tk_MainLoop is a procedure that loops repeatedly calling Tcl_DoOneEvent. It returns only when there are no applications left in this process (i.e. no main windows exist anymore). Most windowing applications will call Tk_MainLoop after initialization; the main execution of the application will consist entirely of callbacks invoked via Tcl_DoOneEvent.
application, event, main loop
To install Tk, copy and paste the appropriate command in to your terminal.
perl -MCPAN -e shell
For more information on module installation, please visit the detailed CPAN module installation guide.