The script below is based upon the Text::CSV documentation:

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

my @Sample_Ids_m;
my $csv = Text::CSV->new( { binary => 1 } )    # should set binary att
+ribute.
  or die "Cannot use CSV: " . Text::CSV->error_diag();


while ( my $row = $csv->getline(*DATA) ) {
    push @Sample_Ids_m, $row->[6];            # Element 6 is the ID
}

say for @Sample_Ids_m;                         # Print the collected I
+Ds

__DATA__
John Doe,G building,05-Aug-2012,08-Aug-2012,"New York City, NY",ABC234
+5,UCD23467, 
John Moe,H building,05-Aug-2012,08-Aug-2012,New York City,DEF2345,UCD8
+0645,
John Slo,I building,05-Aug-2012,08-Aug-2012,New York City,GHI2345,UCD7
+6765,
John Hor,j building,05-Aug-2012,08-Aug-2012,New York City,JKL2345,UCD8
+7111,

[download]

Output:

UCD23467
UCD80645
UCD76765
UCD87111

[download]

Adapted for your csv file (untested):

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

my @Sample_Ids_m;
my $csv = Text::CSV->new( { binary => 1 } )    # should set binary att
+ribute.
  or die "Cannot use CSV: " . Text::CSV->error_diag();

open my $fh, "<", "Merged_CSVfiles.csv" or die "Merged_CSVfiles.csv: $
+!";
while ( my $row = $csv->getline($fh) ) {

    push @Sample_Ids_m, $row->[16];            # Element 16 is the ID
}
$csv->eof or $csv->error_diag();
close $fh;

say for @Sample_Ids_m;                         # Print the collected I
+Ds

[download]

From your code above, it looks like the ID is the 16th element in @columns, and the $row->[16] notation grabs it after parsing a csv line. See if this may assist your scripting...

In reply to Re^5: Why is the following instance of Matching using an array element not working by Kenosis
in thread Why is the following instance of Matching using an array element not working by MyJeweledPerls

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