#!/usr/bin/perl
my $file = shift;
my $new_length = shift;
open (DAT, $file) || die "couldn't open the file!";
my $raw_data = '';
while (<DAT>){
        chomp;
        $raw_data .= $_;
}

my ($offset, $end) = (0, $new_length);

LINE:
while ($end < length($raw_data)) {
	if (substr($raw_data,$end,1)=~m/\s/) {
		substr($raw_data,$end,1,"\n");
		$offset = $end + 1;
		$end = $offset+$new_length;
		next LINE;
	} else { # backtrack
		$end--;
		while ($end > $offset) {
			if (substr($raw_data,$end,1)=~m/\s/) {
				substr($raw_data,$end,1,"\n");
				$offset = $end + 1;
				$end = $offset+$new_length;
				next LINE;
			} 
			--$end;
		}
		# No whitespace split in mid word
		$end = $offset+$new_length;
		substr($raw_data,$end,1,"\n");
		$offset = $end + 1;
		$end = $offset+$new_length;
		next LINE;

	}
}


$raw_data .= "\n" unless $raw_data=~m/\n$/;

print $raw_data;