file I/O best practices

read.pl

my $filename = 'data.txt';
if (open(my $in, '<', $filename)) {
  while (my $row = <$in>) {
    chomp $row;
    print "$row\n";
  }
} else {
  warn "Could not open file '$filename' $!";
}

write.pl

my $filename = 'data.txt';
if (open(my $out, '>', $filename)) {
  while (my $row = <$out>) {
    chomp $row;
    print "$row\n";
  }
} else {
  warn "Could not open file '$filename' $!";
}