#!/usr/bin/perl

use strict;
use warnings;

my $var = "this is just a sample of a string, there is nothing really important in the scalar, just a lot of text";
my @box = split(/\b/, $var);
my @line;

while (@box) {
  shrink();
}

sub shrink {
  my $word = '';
  while (length $word <= 10) {
    last unless (@box);
    $word .= shift @box;
  }
  push (@line, $word);
}

print join("\n", @line), "\n";