PHP: Getting the name of the host a script is running on and the name of the operating system user that the PHP process runs under

hostname.php

<?php declare(strict_types=1);
/**
 * @return non-empty-string
 */
private function hostname(): string
{
    $candidate = gethostname();

    if ($candidate === false) {
        return 'unknown';
    }

    $candidate = trim($candidate);

    if ($candidate === '') {
        return 'unknown';
    }

    return $candidate;
}

username.php

<?php declare(strict_types=1);
/**
 * @return non-empty-string
 */
function userName(): string
{
    if (function_exists('posix_getpwuid') && function_exists('posix_geteuid')) {
        $candidate = trim(posix_getpwuid(posix_geteuid())['name']);
    } elseif (PHP_OS_FAMILY === 'Windows') {
        $candidate = trim((string) getenv('USERNAME'));
    }

    if (!isset($candidate) || $candidate === '') {
        return 'unknown';
    }

    return $candidate;
}