PHP - Zipping Files On Demand

Hello Everyone,

I seem to have stumbled upon something that looks like it is next to impossible in PHP; zipping files/folders on demand in php :p

So, after doing some extensive google searching, I have found various functions; some work only zipping files, other have no comments, some just don't work at all, etc.  After looking at multiple projects, I have finally compiled something that works and has some sort of comments on what the heck is going on.
Code: [Select]
<?php
class zipfile
{
/**
     * Array to store compressed data
     *
     * @var  array    $datasec
     */
    var $datasec      = array();

    /**
     * Central directory
     *
     * @var  array    $ctrl_dir
     */
    var $ctrl_dir     = array();

    /**
     * End of central directory record
     *
     * @var  string   $eof_ctrl_dir
     */
    var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";

    /**
     * Last offset position
     *
     * @var  integer  $old_offset
     */
    var $old_offset   = 0;

 /**
  * Add a directory
  *
  * @var string $name
  */
function add_dir($name) {
$name = str_replace("", "/", $name);
$fr = "\x50\x4b\x03\x04";
$fr .= "\x0a\x00";
$fr .= "\x00\x00";
$fr .= "\x00\x00";
$fr .= "\x00\x00\x00\x00";
$fr .= pack("V",0);
$fr .= pack("V",0);
$fr .= pack("V",0);
$fr .= pack("v", strlen($name) );
$fr .= pack("v", 0 );
$fr .= $name;
$fr .= pack("V", 0);
$fr .= pack("V", 0);
$fr .= pack("V", 0);
$this -> datasec[] = $fr;
$new_offset = strlen(implode("", $this->datasec));
$cdrec = "\x50\x4b\x01\x02";
$cdrec .="\x00\x00";
$cdrec .="\x0a\x00";
$cdrec .="\x00\x00";
$cdrec .="\x00\x00";
$cdrec .="\x00\x00\x00\x00";
$cdrec .= pack("V",0);
$cdrec .= pack("V",0);
$cdrec .= pack("V",0);
$cdrec .= pack("v", strlen($name) );
$cdrec .= pack("v", 0 );
$cdrec .= pack("v", 0 );
$cdrec .= pack("v", 0 );
$cdrec .= pack("v", 0 );
$cdrec .= pack("V", 16 );
$cdrec .= pack("V", $this -> old_offset );
$cdrec .= $name;
$this -> ctrl_dir[] = $cdrec;
$this -> old_offset = $new_offset;
}

/**
 * Converts an Unix timestamp to a four byte DOS date and time format (date
 * in high two bytes, time in low two bytes allowing magnitude comparison).
 *
 * @param  integer  the current Unix timestamp
 *
 * @return integer  the current date in a four byte DOS format
 *
 * @access private
 */
function unix2DosTime($unixtime = 0) {
$timearray = ($unixtime == 0) ? getdate() : getdate($unixtime);

if ($timearray['year'] < 1980) {
$timearray['year']    = 1980;
$timearray['mon']     = 1;
$timearray['mday']    = 1;
$timearray['hours']   = 0;
$timearray['minutes'] = 0;
$timearray['seconds'] = 0;
} // end if

return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) |
($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
} // end of the 'unix2DosTime()' method

/**
     * Adds "file" to archive
     *
     * @param  string   file contents
     * @param  string   name of the file in the archive (may contains the path)
     *
     * @access public
     */
function add_file($data, $name) {
// Read the file
$fp = fopen($data,"r");
$data = fread($fp,filesize($data));
fclose($fp);

// Clean the file name
$name = str_replace("", "/", $name);

$dtime    = dechex($this->unix2DosTime(0));
        $hexdtime = '\x' . $dtime[6] . $dtime[7]
                  . '\x' . $dtime[4] . $dtime[5]
                  . '\x' . $dtime[2] . $dtime[3]
                  . '\x' . $dtime[0] . $dtime[1];
        eval('$hexdtime = "' . $hexdtime . '";');

        $fr   = "\x50\x4b\x03\x04";
        $fr   .= "\x14\x00";            // ver needed to extract
        $fr   .= "\x00\x00";            // gen purpose bit flag
        $fr   .= "\x08\x00";            // compression method
        $fr   .= $hexdtime;             // last mod time and date

// "local file header" segment
        $unc_len = strlen($data);
        $crc     = crc32($data);
        $zdata   = gzcompress($data);
$zdata   = substr(substr($zdata, 0, strlen($zdata) - 4), 2); // fix crc bug
$c_len   = strlen($zdata);
$fr      .= pack('V', $crc);             // crc32
        $fr      .= pack('V', $c_len);           // compressed filesize
        $fr      .= pack('V', $unc_len);         // uncompressed filesize
        $fr      .= pack('v', strlen($name));    // length of filename
        $fr      .= pack('v', 0);                // extra field length
        $fr      .= $name;

// "file data" segment
        $fr .= $zdata;

// add this entry to array
$this -> datasec[] = $fr;

// now add to central directory record
$new_offset = strlen(implode("", $this->datasec));

$cdrec = "\x50\x4b\x01\x02";
$cdrec .="\x00\x00";
$cdrec .="\x14\x00";
$cdrec .="\x00\x00";
$cdrec .="\x08\x00";
$cdrec .="\x00\x00\x00\x00";
$cdrec .= pack("V",$crc);
$cdrec .= pack("V",$c_len);
$cdrec .= pack("V",$unc_len);
$cdrec .= pack("v", strlen($name) );
$cdrec .= pack("v", 0 );
$cdrec .= pack("v", 0 );
$cdrec .= pack("v", 0 );
$cdrec .= pack("v", 0 );
$cdrec .= pack("V", 32 );
$cdrec .= pack("V", $this -> old_offset );

$this -> old_offset = $new_offset;

$cdrec .= $name;
$this -> ctrl_dir[] = $cdrec;
}

/**
     * Dumps out file
     *
     * @return  string  the zipped file
     *
     * @access public
     */
    function file()
    {
        $data    = implode('', $this -> datasec);
        $ctrldir = implode('', $this -> ctrl_dir);

        return
            $data .
            $ctrldir .
            $this -> eof_ctrl_dir .
            pack('v', sizeof($this -> ctrl_dir)) .  // total # of entries "on this disk"
            pack('v', sizeof($this -> ctrl_dir)) .  // total # of entries overall
            pack('V', strlen($ctrldir)) .           // size of central dir
            pack('V', strlen($data)) .              // offset to start of central dir
            "\x00\x00";                             // .zip file comment length
    }
}

// Test this class
$zipTest = new zipfile();
$zipTest->add_dir("images/");
$zipTest->add_file("images/test.jpg", "test.jpg");
$zipTest->add_file("images/test2.jpg", "images/test2.jpg");

// Return Zip File to Browser
Header("Content-type: application/octet-stream");
Header ("Content-disposition: attachment; filename=zipTest.zip");
echo $zipTest->file();
?>

On windows and linux, this class works flawlessly.  On a Mac, this works with the stuffit program, but the default archive program does not like the zips if it contains a directory.  If you comment out  $zipTest->add_dir("images/");, the archive will work great on a Mac as well.

Could someone help me get this class to create a working directory on a  Mac as well?  I am at a point where I would be willing to pay for your time if you can help me get this working (via paypal of course). 

Thanks in advance!
weeee