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

chomp( my @lines = (<DATA>) );
my $num = @lines;
my $count = 1;
for my $line ( @lines ) {
    say "the last line is $line" if $num == $count++;
}

__DATA__
foo
bar
baz
qux

##</code><code>##

$ perl 1202892.pl
the last line is qux

##</code><code>##

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__

##</code><code>##

$ perl 1202892-2.pl
the last line is m