Perl array not saving all variables - arrays

Question

I have a Perl program that's parsing data from an external program and saving it to an array. However, some of the data isn't being saved and comes back blank when trying to retrieve it later.
Here's the code parsing the data, which comes through as #packetData:
if(#packetData[0] ne ""){
if(!$detectedClient{"#packetData[0]"}) {
my $rawSignal = average(#packetData[2]);
my $distance = 10**((27.55-(20*logten(2437))+abs($rawSignal))/20);
my #newClient = ($rawSignal, # Signal (dBm)
1, # Count
#packetData[0], # Source MAC
time(), # Last seen
$distance); # Distance (m)
$detectedClient{"#packetData[0]"} = [#newClient];
$uniqueClient++;
print "++ New probe request from #packetData[0] [$rawSignal dBm, $distance m]\n";
} else {
$detectedClient{"#packetData[0]"}[1]++;
$detectedClient{"#packetData[0]"}[3] = time();
}
}
The print statement shows the signal and distance fine, but trying to show it from the detectedClient array gives with the code below gives a blank space:
for $key2 ( keys %detectedClient) {
#Signal, Count, MAC, Time
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime($detectedClient{$key2}[3]);
my $lastSeen = sprintf("%04d/%02d/%02d %02d:%02d:%02d", $year+1900, $mon+1, $mday, $hour, $min, $sec);
print STDOUT sprintf("!! %-20s %10s %-20s\n", $detectedClient{$key2}[2], $detectedClient{$key2}[1], $lastSeen, $detectedClient{$key2}[0], $detectedClient{$key2}[4]);
}
Any ideas why this is happening?

Answer 1

The signal and the distance aren't printed because your pattern ("!! %-20s %10s %-20s\n") doesn't reference them (the 4th and 5th values). Fix:
printf("!! %-20s %5s %-20s %20s %20s\n",
$detectedClient{$key2}[2],
$detectedClient{$key2}[1],
$lastSeen,
$detectedClient{$key2}[0],
$detectedClient{$key2}[4],
);
Tested using the following: (Had to change for $key2 to for my $key2 too)
use strict;
use warnings qw( all );
use List::Util qw( sum );
sub average { sum(#{ $_[0] })/#{ $_[0] } }
sub logten { log($_[0])/log(10) }
my #packetData = ("foo", undef, [ 4, 5 ]);
my %detectedClient;
my $uniqueClient;
if(#packetData[0] ne ""){
if(!$detectedClient{"#packetData[0]"}) {
my $rawSignal = average(#packetData[2]);
my $distance = 10**((27.55-(20*logten(2437))+abs($rawSignal))/20);
my #newClient = ($rawSignal, # Signal (dBm)
1, # Count
#packetData[0], # Source MAC
time(), # Last seen
$distance); # Distance (m)
$detectedClient{"#packetData[0]"} = [#newClient];
$uniqueClient++;
print "++ New probe request from #packetData[0] [$rawSignal dBm, $distance m]\n";
} else {
$detectedClient{"#packetData[0]"}[1]++;
$detectedClient{"#packetData[0]"}[3] = time();
}
}
for my $key2 ( keys %detectedClient) {
#Signal, Count, MAC, Time
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime($detectedClient{$key2}[3]);
my $lastSeen = sprintf("%04d/%02d/%02d %02d:%02d:%02d", $year+1900, $mon+1, $mday, $hour, $min, $sec);
printf("!! %-20s %5s %-20s %20s %20s\n",
$detectedClient{$key2}[2],
$detectedClient{$key2}[1],
$lastSeen, $detectedClient{$key2}[0],
$detectedClient{$key2}[4],
);
}
Output:
Scalar value #packetData[0] better written as $packetData[0] at a.pl line 18.
Scalar value #packetData[0] better written as $packetData[0] at a.pl line 19.
Scalar value #packetData[2] better written as $packetData[2] at a.pl line 20.
Scalar value #packetData[0] better written as $packetData[0] at a.pl line 24.
Scalar value #packetData[0] better written as $packetData[0] at a.pl line 27.
Scalar value #packetData[0] better written as $packetData[0] at a.pl line 29.
Scalar value #packetData[0] better written as $packetData[0] at a.pl line 31.
Scalar value #packetData[0] better written as $packetData[0] at a.pl line 32.
++ New probe request from foo [4.5 dBm, 0.0164302613184467 m]
!! foo 1 2016/05/16 15:19:38 4.5 0.0164302613184467
Next time, please provide a minimal, runnable demonstration of the problem.

Answer 2

The syntax for an entire array is #array but to access individual elements, it is (e.g.) $array[0]
Also, there is a better way to write the inner if in your context.
Third, you're using an array reference for detectedClient, so the syntax could be changed from $detectedClient{$smac}[1]++ to $detectedClient{$smac}->[1]++ that would be clearer as to intent. I've changed it in the code below, and you'll could also change it when printing as well.
Here's your code modified to reflect all that and shortened to use a scalar:
my $smac = $packetData[0];
if ($smac ne "") {
if(! ref($detectedClient{$smac})) {
my $rawSignal = average($packetData[2]);
my $distance = 10**((27.55-(20*logten(2437))+abs($rawSignal))/20);
my #newClient = ($rawSignal, # Signal (dBm)
1, # Count
$smac, # Source MAC
time(), # Last seen
$distance); # Distance (m)
$detectedClient{$smac} = [#newClient];
$uniqueClient++;
print "++ New probe request from $smac [$rawSignal dBm, $distance m]\n";
} else {
my $ptr = $detectedClient{$smac};
$ptr->[1]++;
$ptr->[3] = time();
}
}
UPDATE:
Applying the use of a scalar and a bit of reindent, the print code looks like:
for $key2 ( keys %detectedClient) {
my $ptr = $detectedClient{$key2};
#Signal, Count, MAC, Time
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
localtime($ptr->[3]);
my $lastSeen = sprintf("%04d/%02d/%02d %02d:%02d:%02d",
$year+1900, $mon+1, $mday, $hour, $min, $sec);
print STDOUT sprintf("!! %-20s %10s %-20s\n",
$ptr->[2], $ptr->[1],
$lastSeen, $ptr->[0], $ptr->[4]);
}
Now, it's a little easier to see [for me, at least ;-)] that the format is short by two fields [so the last two arguments won't be printed].
So, something like this instead:
printf("!! %-20s %10s %-20s %10s %10s\n",