i need help...im trying to create a way to take a string of numbers seperated by commas, sort them numerically (ala Sorting by_number, credit to ncw), and in the process, turn any consecutive group of numbers into a range (eg: 3,4,5,6,7 would be 3-7), then rejoin all the numbers and ranges of numbers by commas again...now, i've written a script to do this, but it's not even coming close to working, and i can't figure out why...it might be some small thing i'm overlooking, like a missing dash or bracket, or it might be my whole method of doing it...(TMTOWTDI) 
# example input string
$in = '1089,3,4,5,6,7,99,832,1087,831,1088';

@i = split(/,/,$in);

# resort the array numerically
@read = sort by_number @i;

$list = '';

foreach $i (0..$#read) {
    if(($read[$i]+1) == $read[$i+1]) {
        $list .= $read[$i].'-'.$read[$i+1].',';
    } else {
        $list .= $read[$i].',';
    }
}

$list =~ s/(\d+)\,\1\-/\1\,/g;

# output the finished product
print $list;

# again, credit to ncw for the sort method
sub by_number
{
    my @a = split /(\d+)/, $a;
    my @b = split /(\d+)/, $b;
    while (@a && @b)
    {
        my ($aa, $bb) = (shift(@a), shift(@b));
        my $res = ($aa =~ /^\d/ && $bb =~ /^\d/) ?
            $aa <=> $bb :
            $aa cmp $bb ;
        return $res if $res;
    }
    return @a <=> @b;
}

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In reply to Sorting and ranging problems... by Anonymous Monk

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