# Use auto_diag to see all parsing errors immediately
my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1, allow_whitespace => 1 });
open my $fh, "<", $file_to_parse or die "Could not open '$file' $!";
while (my $row = $csv->getline ($fh)) {

    # Check first and third field to be numeric only (and not empty)
    $row->[0] =~ m/^[0-9]+$/ && $row->[2] =~ m/^[0-9]+$/ or
        exit;        # wrong format

    # THERE CANNOT BE AN ELSE AFTER AN EXIT !
    }