#!/usr/bin/perl
use strict;
use warnings;

my $range="0-2,6-10,13,15";
my $test="this is a test with more than 15 characters";

for my $r (split (",",$range))
{
	if ($r =~ /^(\d+)(-(\d+))?$/)
	{
		my $first=$1;
		my $length=1;
		if (defined ($3))
		{
			$length=$3-$1+1;
		}

		print "$r - ", substr ($test, $first,$length),"\n";
	}
}

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;

my $range="0-2,6-10,13,15";
my @range=split(",",$range);
my $test="this is a test with more than 15 characters";

my $last=0;
my $regex="";
for (@range)
{
	if (/^(\d+)(-(\d+))?$/)
	{
		my $first=$1;
		my $length=1;

		if ($last lt $first)
		{
			$regex.="."x($last-$first);
		}
		$last=$first;
		if (defined ($3))
		{
			$length=$3-$1+1; $last=$3;
		}
		$regex.="(".("."x$length).")";
	}
}

my @matches = $test =~ /$regex/;

my $n=0;
for (@matches)
{
	print ++$n." ($range[$n-1]): \"" ."$_","\"\n";
}