#! perl -snli.org
use strict;
use vars qw[$B $E $R $s];
BEGIN{
    @ARGV= map{glob}@ARGV; # Not necc. on *nix
    $s=0
}

	/<!- $B -->/ .. (/<!- $E -->/ && ($s = 1))
	? ($s and print($R), $s = 0 )
	: print