use strict;
use warnings;

local $/='end';
my @aFound;
while (my $line=<DATA>) {
  # normally we would chomp to get rid of 'end'
  # but this may not be a good idea if the file ends in
  # junk outside of start ... end.
  # chomp $line;

  # make sure we really have a match just in case there is
  # an 'end' without a preceding "start"!
  # also use the s modifier at the end of your regex so that
  # . matches "\n"
  # see http://perldoc.perl.org/perlre.html#Modifiers
  # for further information
  
  next unless ($line =~ /\s+start\s+(.*)end\z/s);

  # store extracted string for later use
  push @aFound, $1;
}

# do something with the text between start...end
# you'll want to change this:
# your post looks like you would like to further separate
# each word on a separate line, but for now, lets just
# print out the run of characters between start...end.

print join("\n", @aFound), "\n";

__DATA__
asdasd start asdasd asdasdasd asdasdas end asdasdas

adasdas start as asdas dasdasdad asdasddas end qweqwe

asdasd start asdsadsdasddasds sdasdas asdasdasdasd asdasdsa
asdasd asdasdasd end
here is some trailing garbage

##</code><code>##

asdasd asdasdasd asdasdas 
as asdas dasdasdad asdasddas 
asdsadsdasddasds sdasdas asdasdasdasd asdasdsa
asdasd asdasdasd