#!/usr/bin/env perl

use Modern::Perl;
use Text::CSV;

my $csv = Text::CSV->new;

my @strings = (
    'a,"b,c",3,4,5,6',
    'a,"b,c",3,4,5',
    'a,"b,c",3,4,5,""',
    'abc,def,"ghi,jkl",,mno,6'
);

foreach my $s (@strings) {
    if (my $status = $csv->parse($s)) {
        if ( (grep { /\w/ } $csv->fields) != 6 ) {
            warn "row failed: ", $csv->string
        }
    }
    else {
        warn $csv->error_input
    }
}