use strict;
use warnings;
use diagnostics;
use Data::Dumper qw(Dumper);

our (@uniqueMac);
while (<>) {
my ($dateHour,$usrMac,$apMac) = (/regex/);

push (@usrMac, $usrMac);
@uniqueMac = map {$_ = 1} @usrMac;
push (@array, $dateHour{$apMac} = scalar(@uniqueMac);
}
print @array;

##</code><code>##

Date , Hour: AP# : Unique Devices per AP per Hour
$dateHour : $apMac : scalar(@uniqueMac)
2014-04-07, Hour 01: AP1 : 301
2014-04-07, Hour 01: AP2 : 313
2014-04-07, Hour 01: AP3 : 132
. . . every hour per day . . .
2014-04-07, Hour 21: AP1 : 130
2014-04-07, Hour 21: AP2 : 310
2014-04-07, Hour 21: AP3 : 13
. . . for every day . . .
2014-04-08, Hour 01: AP1 : 302
2014-04-08, Hour 01: AP2 : 321
2014-04-08, Hour 01: AP3 : 131
. . . every hour per day . . .
2014-04-08, Hour 22: AP1 : 122
2014-04-08, Hour 22: AP2 : 234
2014-04-08, Hour 22: AP3 : 311