$/ = undef;

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;

local $/ = undef;
my $info = <DATA>;

while ( $info =~ /<tag>(.+?)<\/tag>/g ) {
        print "$1\n";
}

__DATA__
<tag>This is a line</tag>
<tag>This one goes
over multiple lines</tag>

__END__