How to count an array with condition

December 29, 2022

I have a list of hosts with interface.
The code must count the repeated interfaces per host.
Also at the end the code must show the repeating interfaces X times, per host.

I am asking this because I want to send an alert that X host has a failing X interface or more failing interfaces.

$data = array(
    array("192.168.0.1","eth1"),
    array("192.168.0.2","eth2"),
    array("192.168.0.3","eth3"),
    array("192.168.0.1","eth1"),
    array("192.168.0.4","eth1"),
    array("192.168.0.2","eth5")
);

I followed other examples in here, but most of them are for simple arrays or if multidimensional example then the examples aren’t similar.

I have tried this…

<?php
$data = array(
    array("192.168.0.1","eth1"),
    array("192.168.0.2","eth2"),
    array("192.168.0.3","eth3"),
    array("192.168.0.1","eth1"),
    array("192.168.0.4","eth1"),
    array("192.168.0.2","eth5")
);


$counter_data = count($data);

$duplicated_host = array_filter(array_count_values(array_column($data, 0)), function($v) { return $v > 1; });
print_r($duplicated_host);
print ("<br>");

$duplicated_host_keys = (array_keys($duplicated_host));

for ($row_num = 0; $row_num < $counter_data; $row_num++)
{
    $host = $data[$row_num][0];
    $interface = $data[$row_num][1];
    if (in_array($host,$duplicated_host_keys))
    {
        print($host . " " . $interface . "<br>");
    }
    
}

The code above is wrong, somewhat working but it is not what I expect…
Is there a simple way to do this?

At the end the output should look like:

Host 192.168.0.1 has eth1 repeated 2 times. --> For current data only
Host 192.168.0.1 has eth9 repeated 5 times.
Host 192.168.0.4 has eth1 repeated 9 times.

>Solution :

You’ll need to group double, first host, then by interface.

Then you can looop over this grouping array to show/send the output:

<?php

$data = array(
    array("192.168.0.1","eth1"),
    array("192.168.0.2","eth2"),
    array("192.168.0.3","eth3"),
    array("192.168.0.1","eth1"),
    array("192.168.0.4","eth1"),
    array("192.168.0.2","eth5")
);


$result = [];

foreach ($data as $arr) {
    [ $host, $nic ] = $arr;
    if (!isset($result[$host])) {
        $result[$host] = [];
    }
    if (!isset($result[$host][$nic])) {
        $result[$host][$nic] = 0;
    }

    $result[$host][$nic]++;
}


foreach ($result as $host => $nics) {
    foreach ($nics as $nic => $count) {
        echo "${host} has his '${nic}' interface fail ${count} time(s)" . PHP_EOL;
    }
}

192.168.0.1 has his 'eth1' interface fail 2 time(s)
192.168.0.2 has his 'eth2' interface fail 1 time(s)
192.168.0.2 has his 'eth5' interface fail 1 time(s)
192.168.0.3 has his 'eth3' interface fail 1 time(s)
192.168.0.4 has his 'eth1' interface fail 1 time(s)