sleep 1;                     # <--- WORKS!
    #use Time::HiRes 'usleep';   # <--- DOES NOT!!!!!
    #usleep( 2000 );             # <--- ???? 
    my $html = ui_template( 'Regex Editor', '', $html );
    # $html =~ s/\W/_/g;         # no effect
    print $html;
    # close STDIN; close STDOUT; # no effect
    exit 0;                      # no effect