Suggestions to make this code more Perlish

[ricardo_sdl]

I've read about the Text File Format(https://ronaldduncan.wordpress.com/2009/10/31/text-file-formats-ascii-delimited-text-not-csv-or-tab-delimited-text) and decided to create a perl script to convert a csv file to this format.

Instead of using one of the available modules(like Text::CSV) to parse the csv I decided to do it myself as matter of practice.

I'm starting to learn perl and I ask for your wisdom on how to make this code better.

Updated code after some suggestions.

#!/usr/bin/perl
use 5.010;
use strict;
use warnings;
use utf8;
use open qw(:std :utf8);
#Convert a csv file to text file format
#https://ronaldduncan.wordpress.com/2009/10/31/text-file-formats-ascii
+-delimited-text-not-csv-or-tab-delimited-text
#the csv file is expected to use double quotes as the delimiter charac
+ter and utf-8 encoded

sub is_complete_line {
    my ($line) = @_;
    my $inside_double_quotes;
    my $opening_double_quotes = 0;
    my $closing_double_quotes = 0;
    foreach(split('', $line)) {
        next if $_ ne '"';
        
        if ($inside_double_quotes) {
            $inside_double_quotes = ! $inside_double_quotes;
            $closing_double_quotes++;
            next;
        }
        
        $opening_double_quotes++;
        $inside_double_quotes = ! $inside_double_quotes;
    }
    $opening_double_quotes == $closing_double_quotes;
}

sub convert_to_ttf {
    my ($line) = @_;
    my $inside_double_quotes;
    my $converted_line = '';
    foreach(split('', $line)) {
        if ($_ eq '"' && $inside_double_quotes) {
            $inside_double_quotes = 0;
            next;
        }
        
        if ($_ eq '"' && ! $inside_double_quotes) {
            $inside_double_quotes = 1;
            next;
        }
        
        if ($_ eq "," && ! $inside_double_quotes) {
            $converted_line .= "\x{1F}";#unit separator
            next;
        }
        
        if ($_ eq "\n" && ! $inside_double_quotes) {
            $converted_line .= "\x{1E}";#record separator
            next;
        }
        
        $converted_line .= $_;
    }
    $converted_line;
}

open my $fh, '>', "output.txt" or die "Couldn't create the output file
+.\n";

my $line = '';
while (<>) {
    $line .= $_;
    if (is_complete_line($line)) {
        print $fh convert_to_ttf($line);
        $line = '';
    }
    
}

close $fh;

print "Conversion done.\n";

Here is a link to a sample csv file that you can convert(https://db.tt/GWrID417).