silverstripe-framework/tests/phpcs_runner.php

<?php

if (php_sapi_name() != 'cli') {
    die("This script must be called from the command line\n");
}

if (!empty($_SERVER['argv'][1])) {
    $path = $_SERVER['argv'][1];
} else {
    die("Usage: php {$_SERVER['argv'][0]} <file>\n");
}

$result = ['comments' => []];

$extension = pathinfo($path, PATHINFO_EXTENSION);

// Whitelist of extensions to check (default phpcs list)
if (in_array($extension, ['php', 'js', 'inc', 'css'])) {
    // Run each sniff

    // phpcs --encoding=utf-8 --standard=framework/tests/phpcs/tabs.xml
    run_sniff('tabs.xml', $path, $result);

    // phpcs --encoding=utf-8 --tab-width=4 --standard=framework/tests/phpcs/ruleset.xml
    run_sniff('ruleset.xml', $path, $result, '--tab-width=4');
}
echo json_encode($result);

function run_sniff($standard, $path, array &$result, $extraFlags = '')
{
    $sniffPath = escapeshellarg(__DIR__ . '/phpcs/' . $standard);
    $checkPath = escapeshellarg($path);

    exec("phpcs --encoding=utf-8 $extraFlags --standard=$sniffPath --report=xml $checkPath", $output);

    // We can't check the return code as it's non-zero if the sniff finds an error
    if ($output) {
        $xml = implode("\n", $output);
        $xml = simplexml_load_string($xml);
        $errors = $xml->xpath('/phpcs/file/error');
        if ($errors) {
            $sanePath = str_replace('/', '_', $path);
            foreach ($errors as $error) {
                $attributes = $error->attributes();
                $result['comments'][] = [
                    'line' => (int)strval($attributes->line),
                    'id' => $standard . '-' . $sanePath . '-' . $attributes->line . '-' . $attributes->column,
                    'message' => strval($error)
                ];
            }
        }
    }
}