PERL Array count on Array Reference

PERL has a lot of cool built in operators to find things like number of elements in an array an such ($#) which are very straight forward when using basic data types.

With C I never had a problem with the indirection associated with pointers and dereferencing.  Of course, being the pedantic guy I am, I always used parentheses to excess.

Anyway, I was working on some code to retrieve as set of fields back from an Omnibus database and the database function returns a reference to an array of arrays.  I only expect 1 row coming back, but I needed a quick way to tell that.  With a little experimentation I found it was:

$#$resultsPTR

 Sure it is easy now, but I had to run through a few iterations to figure out just what $# wanted to see.

Here is a larger code chunk to put things in perspective, hopefully sanitized enough to  be public:

#!/usr/bin/perl
#
# $Id$
#
use strict;
use warnings;
use diagnostics;
use POSIX ":sys_wait_h";

use lib "/packages";
require "Logging.pm";
require "NcDatabase.pm";
    use NcDatabase qw(ncSetAlertsStatusSeverityZero ncSetAlertsStatusSeverityFive ncSetAlertsJournal);



sub main ()
{
    my ($localhostname)    = Sys::Hostname::hostname();
    my ($dbserver)        = NcDatabase::getDBServForHost($localhostname);
    my ($dbinstance)    = NcDatabase::getDBInstForHost($localhostname);
    my ($dbuser)        = NcDatabase::getMicroMuseDBUser();
    my ($dbpass)        =NcDatabase::getMicroMuseDBPass();
    my ($SQLcommand) = 'select Serial,Summary from alerts.status WHERE Serial >= 5284627';
    my ($resultsPTR);

    Logging::setSyslogLevel ("debug");
    Logging::enableSysloging ();
 
    if ( defined($resultsPTR =  NcDatabase::ncReadTableFromDb("$SQLcommand")) )
    {
        foreach my $row (@$resultsPTR)
        {
            print STDERR "results = " . join(',',@{$row}) . "\n";
        }
    }

    print STDERR "\n\nresults2 = " . join (',',@{$resultsPTR->[0]}) . "\n";
    print STDERR "\nNumber of lines = " . $#$resultsPTR . "\n";

    return (0);
}

main ();