perl -ne'print if /^\[moo\]/../^\[cow\]/ and !/^\[/' log.log

##</code><code>##

use strict;
use warnings;

open FH, '<', 'log.log' or die "can't open file\n";
print "Items found under [moo]\n";
while (<FH>) {
   if (/^\[moo\]/../^\[cow\]/) {
      print unless /^\[/;
   }
}