[Perl-unix-users] Tk::Entry, how can enter key within it run a sub

[Markham, Richard]

Title: Tk::Entry, how can enter key within it run a sub

given the following:

my($input) = $frame3->Entry(-width => 150,
                            -background  => 'white',
                            -foreground  => 'black',
                            -textvariable=> \$inputcmd)->pack;

How could I cause a return key press within this widget to run a subroutine?
Most implementations I see use Button which calls a sub which calls a $entry->get.
MainLoop appears to me as something you couldn't add additional code to do such.

TIA