#!/usr/local/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 $pos = 9;
while(( $pos = index($var, ' ', $pos)) > -1 ) {
	substr($var, $pos, 1) = "\n";
	$pos += 10;
}
print "\n$var\n";