/app/lib/Spaph/Fn.php

<?php
/**
 * This is a simple collection of helpful functions.
 *
 *
 */
class Spaph_Fn {
    /**
     * var_export a variable as preformatted html.
     *
     * @input mixed $data
     * @return string
     */
    public static function dump($data)
    {
        return sprintf('<pre class="spaph-dump">%s</pre>',htmlspecialchars(var_export($data,true)));
    }

    /**
     * This is from memic post at php.net uniqid.
     *
     * @param string $separate 
     * @return string
     */
    public static function uuid4($separate='')
    {
        return sprintf( "%04x%04x%s%04x%s%04x%s%04x%s%04x%04x%04x",
            mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ), $separate, mt_rand( 0, 0xffff ), $separate,
            mt_rand( 0, 0x0fff ) | 0x4000, $separate,
            mt_rand( 0, 0x3fff ) | 0x8000, $separate,
            mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ) );
    }

    /**
     * Wrapper around uuid functions.
     */
    public static function uuid()
    {
        return new Spaph_Fn_UUID();
    }

    /**
     * The returned string can be stored in a database.
     *
     * @param string $password
     * @return string
     */
    public static function hashpwd($password,$salt=null)
    {
        if(!isset($salt)) {
            $salt = '$2a$16$'.substr(str_replace('+', '.', base64_encode(pack('N4', mt_rand(), mt_rand(), mt_rand(), mt_rand()))), 0, 22);
        }

        return crypt($password,$salt);
    }

    /**
     * Check pwd against stored pwd.
     *
     * @param string $check_pwd
     * @param string $store_pwd
     * @return boolean 
     */
    public static function checkpwd($check_pwd,$store_pwd)
    {
        return ( crypt($check_pwd,$store_pwd) == $store_pwd );
    }

    public static function shard($hex,$num_of_domains=2)
    {
        // Spread Users across domains. The domains must start with zero. So, if $num_of_domains
        // is 16 then there ought to be Domain0, Domain1, ...Domain15 (16 Domains total).
        // This must be a number that as binary has all its bits set to 1: 2,4,16...
        // num_of_domains 16; // 2^2, 2^4, 2^5, 2^6, 2^7, 2^8, ...

         // Convert the number of available domains (minus 1) into binary
        $num_of_domains_binary = base_convert($num_of_domains-1,10,2);

        // Sanity check
        if(!preg_match('/^1+$/',$num_of_domains_binary)) {
            throw new Exception("The number of domains ($num_of_domains), as binary, does not have all bits set to 1 ($num_of_domains_binary).");
        }

        // Get the 8 right most hexadecimal digits and convert it to a zero padded binary number.
        // for example, 6b4cc7b2 = 01101011010011001100011110110010 
        $lsb_32 = sprintf("%032s",base_convert(substr($hex, -8),16,2)); 

        // Grab the right most binary digits we are interested in and convert that to decimal.
        // The decimal number must be between 0 and $num_of_domains-1
        $domain = base_convert(substr($lsb_32, -strlen($num_of_domains_binary)),2,10);

        // Here is the Domain!
        return $domain;
    }

    /**
     * http://stackoverflow.com/questions/997078/email-regular-expression
     */
    public static function validEmail($email, $skipDNS = false)
    {
        $isValid = true;
        $atIndex = strrpos($email, "@");
        if (is_bool($atIndex) && !$atIndex)
        {
               $isValid = false;
        }
        else
        {
               $domain = substr($email, $atIndex+1);
               $local = substr($email, 0, $atIndex);
               $localLen = strlen($local);
               $domainLen = strlen($domain);
               if ($localLen < 1 || $localLen > 64)
               {
                      // local part length exceeded
                      $isValid = false;
               }
               else if ($domainLen < 1 || $domainLen > 255)
               {
                      // domain part length exceeded
                      $isValid = false;
               }
               else if ($local[0] == '.' || $local[$localLen-1] == '.')
               {
                      // local part starts or ends with '.'
                      $isValid = false;
               }
               else if (preg_match('/\\.\\./', $local))
               {
                      // local part has two consecutive dots
                      $isValid = false;
               }
               else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain))
               {
                      // character not valid in domain part
                      $isValid = false;
               }
               else if (preg_match('/\\.\\./', $domain))
               {
                      // domain part has two consecutive dots
                      $isValid = false;
               }
               else if (!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/', str_replace("\\\\","",$local)))
               {
                      // character not valid in local part unless 
                      // local part is quoted
                      if (!preg_match('/^"(\\\\"|[^"])+"$/', str_replace("\\\\","",$local)))
                      {
                             $isValid = false;
                      }
               }
    
               if(!$skipDNS)
               {
                       if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A")))
                       {
                              // domain not found in DNS
                              $isValid = false;
                       }
               }
        }
        return $isValid;
    }

    public static function randomStr($length=8)
    {
        $chars     = '=bcdfghjkmnpqrstvwxyzBCDFGHJKMNPQRSTVWXYZ23456789%';
        $num_chars = strlen($chars); 
        $result    = '';

        for($i=0; $i<$length; $i++) {
            $result .= $chars[rand(0,$num_chars-1)];
        }

        return $result;
    }
    
    /**
     * Destroy php session convincingly.
     */
    public static function dSession()
    {
        $_SESSION = array();
        $ck = session_get_cookie_params();
        setcookie(session_name(), '', time()-2592000, $ck['path'], $ck['domain'], $ck['secure']);
        unset($_COOKIE[session_name()]);
        session_destroy();
    }
    
    /**
     * getBytes
     *
     * Convert G,M,K to bytes. Call like Spaph_Fn::getBytes('20M');
     *
     * @param string
     * @return integer
     */
    public static function getBytes($val) {
        $val = trim($val);
        $val = str_ireplace('B', '', $val); // Remove B from instances of KB,MB,GB
        
        if(!$val) {
            return;
        }
        
        $last = strtolower($val[strlen($val)-1]);

        switch($last) {
            // The 'G' modifier is available since PHP 5.1.0
            case 'g':
                $val *= 1024;
            case 'm':
                $val *= 1024;
            case 'k':
                $val *= 1024;
        }

        return $val;
    }

    /**
     * FormatByteSize
     *
     * Convert bytes into KB,MB,GB.
     *
     * @param integer
     * @return string
     */
    public static function FormatByteSize($bytes)
    {
        $size = $bytes / 1024;
        $sig = '';
        if($size < 1024) {
            $size = number_format($size, 2);
            $sig  = 'KB';
        }
        else {
            if($size / 1024 < 1024) {
                $size = number_format($size / 1024, 2);
                $sig  = 'MB';
            }
            else if ($size / 1024 / 1024 < 1024) {
                $size = number_format($size / 1024 / 1024, 2);
                $sig  = 'GB';
            }
        }

        return floor($size).$sig;
        //$size = preg_replace('/\.00/','',$size);
    }

    /**
     * http://www.technischedaten.de/pmwiki2/pmwiki.php?n=Php.BaseConvert
     *
     * // Convert number from base 10 to base 36.
     * bc_base_convert(232456,10,36)
     *
     * @param integer $value
     * @param integer $quellformat 2-62
     * @param integer $zielformat 2-62
     */
    function bc_base_convert($value,$quellformat,$zielformat)
    {
        $vorrat = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
        if(max($quellformat,$zielformat) > strlen($vorrat))
            trigger_error('Bad Format max: '.strlen($vorrat),E_USER_ERROR);
        if(min($quellformat,$zielformat) < 2) 
            trigger_error('Bad Format min: 2',E_USER_ERROR);
        $dezi   = '0';
        $level  = 0;
        $result = '';
        $value  = trim((string)$value,"\r\n\t +");
        $vorzeichen = '-' === $value{0}?'-':'';
        $value  = ltrim($value,"-0");
        $len    = strlen($value);
        for($i=0;$i<$len;$i++)
        {
          $wert = strpos($vorrat,$value{$len-1-$i});
          if(FALSE === $wert) trigger_error('Bad Char in input 1',E_USER_ERROR);
          if($wert >= $quellformat) trigger_error('Bad Char in input 2',E_USER_ERROR);
          $dezi = bcadd($dezi,bcmul(bcpow($quellformat,$i),$wert));
        }
        if(10 == $zielformat) return $vorzeichen.$dezi; // abk?
        while(1 !== bccomp(bcpow($zielformat,$level++),$dezi));
        for($i=$level-2;$i>=0;$i--)
        {
          $factor  = bcpow($zielformat,$i);
          $zahl    = bcdiv($dezi,$factor,0);
          $dezi    = bcmod($dezi,$factor);
          $result .= $vorrat{$zahl};
        }
        $result = empty($result)?'0':$result;
        return $vorzeichen.$result ;
    }
}