blue-twilight/app/Helpers/MiscHelper.php

<?php

namespace App\Helpers;

class MiscHelper
{
    public static function convertToBytes($val)
    {
        if(empty($val))return 0;

        $val = trim($val);

        preg_match('#([0-9]+)[\s]*([a-z]+)#i', $val, $matches);

        $last = '';
        if(isset($matches[2])){
            $last = $matches[2];
        }

        if(isset($matches[1])){
            $val = (int) $matches[1];
        }

        switch (strtolower($last))
        {
            case 'g':
            case 'gb':
                $val *= 1024;
            case 'm':
            case 'mb':
                $val *= 1024;
            case 'k':
            case 'kb':
                $val *= 1024;
        }

        return (int) $val;
    }

    public static function gravatarUrl($emailAddress, $size = 48, $default = 'identicon')
    {
        $hash = md5(strtolower(trim($emailAddress)));
        return sprintf('https://www.gravatar.com/avatar/%s?s=%d&d=%s', $hash, $size, $default);
    }

    /**
     * Tests whether the provided URL belongs to the current application (i.e. both scheme and hostname match.)
     * @param $url
     * @return bool
     */
    public static function isSafeUrl($url)
    {
        $parts = parse_url($url);
        $validParts = parse_url(url('/'));

        return ($parts['scheme'] == $validParts['scheme'] && $parts['host'] == $validParts['host']);
    }

    public static function randomString($length = 10)
    {
        $seed = 'abcdefghijklmnopqrstuvwxyz01234567890';
        $string = '';

        while (strlen($string) < $length)
        {
            $string .= substr($seed, rand(0, strlen($seed) - 1), 1);
        }

        return $string;
    }
}