<?php

function is_cli() {
    if (defined('STDIN')) {
        return true;
    }

    if (php_sapi_name() === 'cli') {
        return true;
    }

    if (array_key_exists('SHELL', $_ENV)) {
        return true;
    }

    if (empty($_SERVER['REMOTE_ADDR']) and ! isset($_SERVER['HTTP_USER_AGENT']) and count($_SERVER['argv']) > 0) {
        return true;
    }

    if (!array_key_exists('REQUEST_METHOD', $_SERVER)) {
        return true;
    }

    return false;
}

if (is_cli() === false) {
    echo('Unable to Start');
    exit(1);
}

function getOSInformation() {
    if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
        return ['name' => 'Windows'];
    }

    if (false == function_exists("shell_exec") || false == is_readable("/etc/os-release")) {
        return null;
    }

    $os = shell_exec('cat /etc/os-release');
    $listIds = preg_match_all('/.*=/', $os, $matchListIds);
    $listIds = $matchListIds[0];

    $listVal = preg_match_all('/=.*/', $os, $matchListVal);
    $listVal = $matchListVal[0];

    array_walk($listIds, function(&$v, $k) {
        $v = strtolower(str_replace('=', '', $v));
    });

    array_walk($listVal, function(&$v, $k) {
        $v = preg_replace('/=|"/', '', $v);
    });

    return array_combine($listIds, $listVal);
}

function is_string_found(string $data, string $find): bool {
    return (stripos($data, $find) !== false);
}

function get_left(string $str, int $length): string {
    return substr($str, 0, $length);
}

function get_right(string $str, int $length): string {
    return substr($str, -$length);
}

$os = getOSInformation();
$osVer = (isset($os['version_id'])) ? $os['version_id'] : false;
$codeName = (isset($os['version_codename'])) ? $os['version_codename'] : false;
$os_like = (isset($os['id_like'])) ? $os['id_like'] : false;