#!/usr/bin/perl

my $file = $ARGV[0];
my $new_length = $ARGV[1];
open (DAT, $file) || die "couldn't open the file!";
my $raw_data = '';
while (<DAT>){
	chop;
	$raw_data .= $_;
}

my @array = split(/%/, $raw_data);
#array holds whole text file
foreach(@array){
	$i = 0;
	@small_array = {};
	$prev_end_of_line = 0;
	#read the current paragraph into an new array
	@small_array = split(//,$_);
	foreach(@small_array){
		#option 1: space found at standard position
		if(($small_array[$prev_end_of_line+$new_length] =~ /\s/)&&$found!=1){
			$prev_end_of_line = $prev_end_of_line+$new_length;
			$found = 1;
		}
		elsif($found!=1){
			#start backtracking
			for($j=($prev_end_of_line+$new_length)-1; ;$j--){
				#option 3: no space found
				if($j==$i&&$i>0){
					$prev_end_of_line =  $prev_end_of_line+$new_length;
					$found = 1;
					last;
				}
				#option 2: space found at position $j
				if($small_array[$j] =~ /\s/){
					$prev_end_of_line = $j;
					$found = 1;
					last;
				}
			}
		}
		print $_;
		$i++;
		if($i eq $prev_end_of_line){
			print "\n";
			$found = 0;
		}
	}
	print "\n%\n";
	$found = 0;
}