IO::Handle->format_line_break_characters( [STR] ) $:
IO::Handle->input_record_separator( [STR] )       $/

##</code><code>##

IO::Handle->input_record_separator( ["\r"] );

##</code><code>##

#!/usr/local/bin/perl
use strict;
use warnings;
use Data::Dumper;
use IO::File;
use Text::CSV_XS;
IO::Handle->input_record_separator( "\r" );
my $file = defined $ARGV[0] ? $ARGV[0] : 'normal.txt';
my $io   = new IO::File "$file", "<" || die "horribly";
my $csv  = new Text::CSV_XS;
# my $test = $io->getline;
# print Data::Dumper->Dump([$test],['io']);
my $columns = $csv->getline($io);
print Data::Dumper->Dump([$columns],['csv']);
exit 0;

##</code><code>##

cat mac.txt | perl -e '$/="\r"; while(<>){$_=~s/\015$/\n/; print $_;}'