#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

my $nix = << '__NIX__';
line 1
line 2
__NIX__

my $win = << '__WIN__'; # ^M present at end of lines.
line 1
line 2
__WIN__

# ^M present here, too:
my $quoted = 'line1
line2
';

say /\r/ for $nix, $win, $quoted;