Make some applications display graph over rrdcached

functions.inc.php

function get_arrays_with_application($device, $app_id, $app_name, $category = null)
{
    $entries = [];
    $apparray = [];
    $separator = '-';

    if ($category) {
        $pattern = sprintf('%s/%s-%s-%s-%s-*.rrd', Rrd::dirFromHost($device['hostname']), 'app', $app_name, $app_id, $category);
    } else {
        $pattern = sprintf('%s/%s-%s-%s-*.rrd', Rrd::dirFromHost($device['hostname']), 'app', $app_name, $app_id);
    }

    // app_name contains a separator character? consider it
    $offset = substr_count($app_name, $separator);

    if (Config::get('rrdcached')) {
        $pattern = sprintf('%s-%s-%s', 'app', $app_name, $app_id);
        // Build the rrdtool cmd to list rrdfiles for this device
        $rrdcmd = sprintf('%s list /%s --daemon %s', Config::get('rrdtool', 'rrdtool'), $device['hostname'], Config::get('rrdcached'));
        $rrd_files = shell_exec($rrdcmd);
        // Split returned files into array
        $rrdarray = preg_split('/\s+/', trim($rrd_files));
        // Find only the rrd files for the app we care about and add them to apparray.
        foreach ($rrdarray as $rrd) {
            if (str_contains($rrd, $pattern)) {
                 array_push($apparray, $rrd); 
           }
        }
    } else {
        $apparray = glob($pattern);
    }
    
    foreach ($apparray as $rrd) {
        $filename = basename($rrd, '.rrd');
        $entry = explode($separator, $filename, 4 + $offset)[3 + $offset];

        if ($entry) {
          array_push($entries, $entry);
        }
    }
    return $entries;
}