use strict; use warnings;
use feature qw/ say /;

# setting up the demo
use Path::Tiny;
my $file = Path::Tiny->tempfile;
$file->spew("$_\n") for ('a' .. 'm');
#######

my $last_line;
open my $fh, '<', $file or die "Cannot open file: $!";
while ( my $line = <$fh> ) {
    chomp $line;
    $last_line = $line;
}

say "the last line is $last_line";

__END__