Introducing Unixish  Unixish is a simple framework for creating
data transformation routines that can be applied to arrays or
streams. The data transformation routines can also be accessed
via command-line, much like your usual Unix utilities. In fact,
the Data::Unixish distribution comes with several clones of Unix
utilities like cat, shuf, head, tail, wc, sort, yes, rev.
Creating a data transformation routine, called a dux function
(where dux is short for Data::Unixish) is easy enough. Let's say
you're creating a function called revline to reverse the
characters of each line of text. You write a function called
revline and place it in Data::Unixish::revline package.  package
Data::Unixish::revline; sub revline {     my %args = @_;     my
($in, $out) = ($args{in}, $args{out});     while (my ($index,
$item) = each @$in) {         $item = reverse($item) if
defined($item);         push @$out, $item;     [200, "OK"];
Several things to note here. First, you accept arguments via a
hash. The input and output are