#!/usr/bin/perl -w
use strict;
use IO::Scalar; # not needed if input and output are from files
use Text::CSV_XS;
my $csv = Text::CSV_XS->new( {binary=>1} );

my @input_data  = <DATA>;

# turn the input data into a CSV string with records and fields
#
my $csv_str = text_to_csv( @input_data );

# as a test, turn the CSV string back into a text string
#
my $output_data = csv_to_text( $csv_str );

# check that the text string created from the CSV is the same
# as the original
#
print "ok!\n" if $output_data eq join '', @input_data;

sub text_to_csv {
    my (@new_row,$new_text,$output_csv,$heading);
    for my $line (@_) {
        if ($line =~ /^(\w+:)$/) {
            $heading = $1;
            if (@new_row) {
                $output_csv .= make_row(@new_row,$new_text);
            }
            @new_row  = ($heading);
            $new_text = '';
        }
        else {
            $new_text .= $line;
        }
    }
    $output_csv .= make_row(@new_row,$new_text);
}
sub csv_to_text {
    my($input_str)=@_;
    my $output_str = '';
    my $fh = IO::Scalar->new(\$input_str);
    while (my $cols = $csv->getline($fh)) {
        last unless @$cols;
        $output_str .= sprintf "%s\n%s", @$cols;
    }
    return $output_str;
}
sub make_row {
    my $success =  $csv->combine(@_);
    die "Coulnd't parse '@_'\n" unless $success;
    return $csv->string . "\n";
}
__DATA__
H1:
T1.1
T1.2
H2:
T2.1
T2.2