Fix for optimized php zip class that now works on windows and mac

<?php
/**
* Original source was created by Rochak Chauhan, www.rochakchauhan.com.
* But it used a lot of memory so it was modified.
* The original code kept the continuesly growing .zip stream in memory and in addition
* adding a new file to the stream required filesize*4 bytes.

* Now the growing .zip stream is not kept in memory, it is written to the file continuesly.
* Adding a new file to the .zip requires filesize*2 bytes of memory.
* Plus some more memory required to store the .zip entries -
* this is written only at the end of the process.
*
* 20.2.2011: Fixed by Michael Dempfle (www.tinywebgallery.com).
*            - The created zip files do now work on Mac.
*            - It also does not require php 5 anymore. It works also fine on php 4.
*            - Compression can be turned off to get more speed if this is important for you.
*            - I also added the patch from Peter Listiak <mlady@users.sourceforge.net>
*              for last modified date and time of the compressed file.
*
* This code based on an older class then the one currently published on phpclasses.org.
* The newer one do also contain
* directory functions. You would have to merge this if you need them.
*
* @author ironhawk, Rochak Chauhan  www.rochakchauhan.com
* @package zip
*/
class ZipFile {

var $centralDirectory = array(); // central directory
var $endOfCentralDirectory = "x50x4bx05x06x00x00x00x00"; //end of Central directory record
var $oldOffset = 0;

var $fileHandle;
var $compressedDataLength = 0;

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;
$timearray['seconds'] = 0; }
return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) | ($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
}

/**
* Creates a new ZipFile object
*
* @param resource $_fileHandle file resource opened using fopen() with "w+" mode
* @return ZipFile
*/
function ZipFile($_fileHandle)
{
$this->fileHandle = $_fileHandle;
}

/**
* Adds a new file to the .zip in the specified .zip folder - previously created using addDirectory()!
*
* @param string $directoryName full path of the previously created .zip folder the file is inserted into
* @param string $filePath full file path on the disk
* @return void
*/
function addFile($filePath, $directoryName, $doCompress = true)   {

// reading content into memory
$data = file_get_contents($filePath);

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

// create some descriptors
$directoryName = str_replace("", "/", $directoryName);
$feedArrayRow = "x50x4bx03x04";
$feedArrayRow .= "x14x00";
$feedArrayRow .= "x00x00";
$feedArrayRow .= "x08x00";
$feedArrayRow .= $hexdtime;
$uncompressedLength = strlen($data);

// compression of the data
$compression = crc32($data);
// at this point filesize*2 memory is required for a moment but it will be released immediatelly
// once the compression itself done
// compression does not work with mac - I use the compression only to download multiple file so I skip it!
if ($doCompress) {
$data = gzcompress($data);
}
// manipulations
$data = substr($data, 2, strlen($data) - 6);

// writing some info
$compressedLength = strlen($data);
// Compression does not work with mac
if ($doCompress) {
$feedArrayRow .= pack("V",$compression);
$feedArrayRow .= pack("V",$compressedLength);
$feedArrayRow .= pack("V",$uncompressedLength);
}
$feedArrayRow .= pack("v", strlen($directoryName) );
$feedArrayRow .= pack("v", 0 );
$feedArrayRow .= $directoryName;
fwrite($this->fileHandle, $feedArrayRow);
$this->compressedDataLength += strlen($feedArrayRow);

// writing out the compressed content
fwrite($this->fileHandle, $data);
$this->compressedDataLength += $compressedLength;

// some more info...
// The part below cause the mac to fail!
//   $feedArrayRow = pack("V",$compression);
//   $feedArrayRow .= pack("V",$compressedLength);
//   $feedArrayRow .= pack("V",$uncompressedLength);
//fwrite($this->fileHandle, $feedArrayRow);
//$this->compressedDataLength += strlen($feedArrayRow);
$newOffset = $this->compressedDataLength;

// adding entry
$addCentralRecord = "x50x4bx01x02";
$addCentralRecord .="x00x00";
$addCentralRecord .="x14x00";
$addCentralRecord .="x00x00";
$addCentralRecord .="x08x00";
$addCentralRecord .= $hexdtime;
$addCentralRecord .= pack("V",$compression);
$addCentralRecord .= pack("V",$compressedLength);
$addCentralRecord .= pack("V",$uncompressedLength);
$addCentralRecord .= pack("v", strlen($directoryName) );
$addCentralRecord .= pack("v", 0 );
$addCentralRecord .= pack("v", 0 );
$addCentralRecord .= pack("v", 0 );
$addCentralRecord .= pack("v", 0 );
$addCentralRecord .= pack("V", 32 );
$addCentralRecord .= pack("V", $this->oldOffset );
$this->oldOffset = $newOffset;
$addCentralRecord .= $directoryName;
$this->centralDirectory[] = $addCentralRecord;

}

/**
* Close the .zip - we do not add more stuff
*
* @param boolean $closeFileHandle if true the file resource will be closed too
*/
function close($closeFileHandle = true) {

$controlDirectory = implode("", $this->centralDirectory);

fwrite($this->fileHandle, $controlDirectory);
fwrite($this->fileHandle, $this->endOfCentralDirectory);
fwrite($this->fileHandle, pack("v", sizeof($this->centralDirectory)));
fwrite($this->fileHandle, pack("v", sizeof($this->centralDirectory)));
fwrite($this->fileHandle, pack("V", strlen($controlDirectory)));
fwrite($this->fileHandle, pack("V", $this->compressedDataLength));
fwrite($this->fileHandle, "x00x00");

if($closeFileHandle)
fclose($this->fileHandle);
}
}
?>

<?php
/**
*  Example how to create the zip.
*
*  Thanks to Rochak Chauhan for the initial implementation and
*  Attila Wind for the memory optimization.
*  I only fixed and extended the class. So the main credits goes to the guys above.
*
*  The TWG Flash Uploader is using this class as well.
*
* 20.2.2011: Fixed by Michael Dempfle (www.tinywebgallery.com).
*            - The created zip files where not working on Mac. Now they do. A couple of elements where added twice!
*            - It also does not require php 5 anymore. It works also fine on php 4.
*            - Compression can be turned off to get more speed if this is important for you.
*            - I also added the patch from Peter Listiak <mlady@users.sourceforge.net>
*              for last modified date and time of the compressed file.
*
*/

include("zip.class.php");
$fileonserver = "filename.txt";
$filename = "example.zip";
$fd = fopen ($filename, "wb");
$createZip = new ZipFile($fd);
$createZip -> addFile($fileonserver, $fileonserver, true);
$createZip -> close();

?>