Create an outage report based on a ping log file

ping-report.php

<?php

/**
 * Create an outage report based on a ping log file.
 *
 * Command: ping <target> -DO >> ping.log
 */


$report = [
    'log' => 'ping.log',
    'min_loss' => 5
];

parseLog();
report();

function parseLog() {
    global $report;

    if ($handle = fopen($report['log'], 'r')) {
        while (($line = fgets($handle)) !== false) {
            parseLine($line);
        }

        fclose($handle);
    } else {
        die('Unable to read the log.');
    }
}

function parseLine($line) {
    global $report;

    if (substr($line, 0, 4 ) === 'PING') {
        getTarget($line);
    } elseif (substr($line, 0, 1) === '[') {
        getResponse($line);
    }
}

function getTarget($line) {
    global $report;

    if (preg_match('/^PING (.*) \((.*)\) \d+\(\d+\) bytes of data\.$/', $line, $matches)) {
        $report['target_host'] = $matches[1];
        $report['target_ip'] = $matches[2];
    } else {
        die('Unable to read the target.');
    }
}

function getResponse($line) {
    global $report;

    if (preg_match('/^\[(\d+)\.\d+\] 64 bytes from/', $line, $matches)) {
        if (!isset($report['log_start'])) {
            $report['log_start'] = $matches[1];
        }

        if (isset($report['status']) && ($report['status'] === 'down')) {
            if ($matches[1] - $report['down_start'] > $report['min_loss']) {
                $report['cycles'][] = [
                    'down' => $report['down_start'],
                    'up' => $matches[1]
                ];
            }

            unset($report['down_start']);
        }

        $report['status'] = 'up';
        $report['log_end'] = $matches[1];
    } elseif (preg_match('/^\[(\d+)\.\d+\] no answer yet for/', $line, $matches)) {
        if (!isset($report['down_start'])) {
            $report['down_start'] = $matches[1];
        }

        $report['status'] = 'down';
        $report['log_end'] = $matches[1];
    } else {
        die('Invalid response: ' . $line);
    }
}

function report() {
    global $report;

    echo "Report Start:\t" . date('r', $report['log_start']) . "\n";
    echo "Report End:\t" . date('r', $report['log_end']) . "\n\n";
    echo "Target:\t\t" . $report['target_ip'] . "\n";
    echo "Outages:\t" . count($report['cycles']) . "\n\n";
    echo "Downtime:\n";

    foreach ($report['cycles'] as $cycle) {
        echo "\t" . date('r', $cycle['down']) . " -> " . date('r', $cycle['up']) . " (" . ($cycle['up'] - $cycle['down']) . " seconds)\n";
    }
}