shlink/module/Common/src/Util/StringUtilsTrait.php

<?php
declare(strict_types=1);

namespace Shlinkio\Shlink\Common\Util;

use function random_int;
use function sprintf;
use function strlen;

trait StringUtilsTrait
{
    private function generateRandomString(int $length = 10): string
    {
        $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
        $charactersLength = strlen($characters);
        $randomString = '';
        for ($i = 0; $i < $length; $i++) {
            $randomString .= $characters[random_int(0, $charactersLength - 1)];
        }

        return $randomString;
    }

    private function generateV4Uuid(): string
    {
        return sprintf(
            '%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
            // 32 bits for "time_low"
            random_int(0, 0xffff),
            random_int(0, 0xffff),
            // 16 bits for "time_mid"
            random_int(0, 0xffff),
            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 4
            random_int(0, 0x0fff) | 0x4000,
            // 16 bits, 8 bits for "clk_seq_hi_res",
            // 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            random_int(0, 0x3fff) | 0x8000,
            // 48 bits for "node"
            random_int(0, 0xffff),
            random_int(0, 0xffff),
            random_int(0, 0xffff)
        );
    }
}