How to count an array with condition - php

Question

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.

Answer 1

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)
Try it online!
NIC --> 'Network Interface Card'

Answer 2

This probably is what you are looking for:
<?php
$input = 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"),
);
$output = [];
array_walk($input, function($entry) use (&$output) {
[$host, $interface] = $entry;
if (isset($host, $output) && isset($interface, $output[$host])) {
$output[$host][$interface]++;
} else {
$output[$host][$interface] = 1;
}
});
print_r($output);
The output is:
Array
(
[192.168.0.1] => Array
(
[eth1] => 2
)
[192.168.0.2] => Array
(
[eth2] => 1
[eth5] => 1
)
[192.168.0.3] => Array
(
[eth3] => 1
)
[192.168.0.4] => Array
(
[eth1] => 1
)
)