Perl text::csv to check then add field - perl

Question

I am reading an csv file and checking for text within a certain field.
If text exists I would like to keep the line and also add a field.
The following while loop in a program works fine, to save lines with text in col[17]:
while (my $row = $csv->getline($infh)) {
if ($row->[16] ne ""){
my $string = $csv->string;
print {$outfh} $string;
}
}
In another test program the following while loop also works fine, to add a field:
while (my $row = $csv->getline($infh)) {
splice #$row, 1, 0, "1GM";
$csv->print($outfh, $row);
}
I would like to combine these to work in the same program but I am having syntax nitemares.
Can anyone show some pointers to a perl novice?
Here is the full "test program":
#!/usr/bin/perl
use strict;
use warnings;
use Text::CSV;
use Cwd;
use File::Basename;
my $dirname = basename(getcwd);
my $input_file = $dirname . ".txt";
my $output_file = $dirname . '_extract.txt';
my $csv = Text::CSV->new({binary => 1, eol=> "\015\012"})
or die "Cannot use CSV: ".Text::CSV->error_diag ();
open my $infh, $input_file or die "Cannot open '$input_file': $!";
open my $outfh, '>>', $output_file or die "Cannot open '$output_file': $!";
while (my $row = $csv->getline($infh)) {
splice #$row, 1, 0, "1GM";
$csv->print($outfh, $row);
}
close $infh;
close $outfh;
$csv->eof or die "Processing of '$input_file' terminated prematurely";
Added:
I would like the test program to also include the test for the text, somehow using;
if ($row->[16] ne "")
From the other program - So that the extra column is only added to the rows I want to keep.
Cannot figure out how to do this...
Added 2/18: This Worked!, but does not seem very elegant...
#!/usr/bin/perl
use strict;
use warnings;
use Text::CSV;
use Cwd;
use File::Basename;
my $dirname = basename(getcwd);
my $input_file = $dirname . ".txt";
my $output_file = $dirname . '_extract.txt';
my $column = '1GM'; # Text for new column to insert if a match
my $csv = Text::CSV->new({binary => 1, eol=> "\015\012"})
or die "Cannot use CSV: ".Text::CSV->error_diag ();
open my $infh, $input_file or die "Cannot open '$input_file': $!";
open my $outfh, '>>', $output_file or die "Cannot open '$output_file': $!";
while (my $row = $csv->getline($infh)) {
if ($row->[16] ne "") # add/insert column if col[17] has text
{
splice #$row, 1, 0, "$column";
if ($row->[1] eq "$column") # print to file only rows with new column
{
$csv->print($outfh, $row);
}
}
}
close $infh;
close $outfh;
$csv->eof or die "Processing of '$input_file' terminated prematurely";
Added 2/18 5:40pm - Got it..This works!!
while (my $row = $csv->getline($infh)) {
splice #$row, 1, 0, "$column"; # add column
if ($row->[17] ne "") # print if test is true
{
$csv->print($outfh, $row);
}
}