<?php
class zipfile {
  var $datasec = array ();
  var $ctrl_dir = array ();
  var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";
  var $old_offset = 0;
  
  function unix2_dostime($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) | ($timearray ['seconds'] >> 1);
  }
  function add_file($data, $name, $time = 0){
    $name = str_replace('\\', '/', $name);
    
    $dtime = dechex($this->unix2_dostime($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 . '";');
    
    $fr = "\x50\x4b\x03\x04";
    $fr .= "\x14\x00";
    $fr .= "\x00\x00";
    $fr .= "\x08\x00";
    $fr .= $hexdtime;
    
    $unc_len = strlen($data);
    $crc = crc32($data);
    $zdata = gzcompress($data);
    $zdata = substr(substr($zdata, 0, strlen($zdata)- 4), 2);
    $c_len = strlen($zdata);
    $fr .= pack('V', $crc);
    $fr .= pack('V', $c_len);
    $fr .= pack('V', $unc_len);
    $fr .= pack('v', strlen($name));
    $fr .= pack('v', 0);
    $fr .= $name;
    
    $fr .= $zdata;
    $fr .= pack('V', $crc);
    $fr .= pack('V', $c_len);
    $fr .= pack('V', $unc_len);
    
    $this->datasec [] = $fr;
    
    $cdrec = "\x50\x4b\x01\x02";
    $cdrec .= "\x00\x00";
    $cdrec .= "\x14\x00";
    $cdrec .= "\x00\x00";
    $cdrec .= "\x08\x00";
    $cdrec .= $hexdtime;
    $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);
    $this->old_offset += strlen($fr);
    
    $cdrec .= $name;
    
    $this->ctrl_dir[] = $cdrec;
  }
  function add_path($path, $l = 0){
    $d = @opendir($path);
    $l = $l > 0 ? $l : strlen($path) + 1;
    while($v = @readdir($d)){
      if($v == '.' || $v == '..'){
        continue;
      }
      $v = $path . '/' . $v;
      if(is_dir($v)){
        $this->add_path($v, $l);
      } else {
        $this->add_file(file_get_contents($v), substr($v, $l));
      }
    }
  }
  function file(){
    $data = implode('', $this->datasec);
    $ctrldir = implode('', $this->ctrl_dir);
    return $data . $ctrldir . $this->eof_ctrl_dir . pack('v', sizeof($this->ctrl_dir)) . pack('v', sizeof($this->ctrl_dir)) . pack('V', strlen($ctrldir)) . pack('V', strlen($data)) . "\x00\x00";
  }
  
  function add_files($files){
    foreach($files as $file){
      if (is_file($file)){
        $data = implode("", file($file));
        $this->add_file($data, $file);
      }
    }
  }
  function output($file){
    $fp = fopen($file, "w");
    fwrite($fp, $this->file ());
    fclose($fp);
  }
} 

//下面是實例操作過程：
$dfile = tempnam('/tmp', 'tmp');//產生一個臨時文件，用于緩存下載文件
$zip = new zipfile();
//----------------------
$filename = 'image.zip'; //下載的默認文件名

//以下是需要下載的圖片數組信息，將需要下載的圖片信息轉化為類似即可
$image = array(
  array('image_src' => 'pic1.jpg', 'image_name' => '圖片1.jpg'),
  array('image_src' => 'pic2.jpg', 'image_name' => 'pic/圖片2.jpg'),
);

foreach($image as $v){
  $zip->add_file(file_get_contents($v['image_src']), $v['image_name']);
  // 添加打包的圖片，第一個參數是圖片內容，第二個參數是壓縮包里面的顯示的名稱, 可包含路徑
  // 或是想打包整個目錄 用 $zip->add_path($image_path);
}
//----------------------
$zip->output($dfile);

// 下載文件
ob_clean();
header('Pragma: public');
header('Last-Modified:'.gmdate('D, d M Y H:i:s') . 'GMT');
header('Cache-Control:no-store, no-cache, must-revalidate');
header('Cache-Control:pre-check=0, post-check=0, max-age=0');
header('Content-Transfer-Encoding:binary');
header('Content-Encoding:none');
header('Content-type:multipart/form-data');
header('Content-Disposition:attachment; filename="'.$filename.'"'); //設置下載的默認文件名
header('Content-length:'. filesize($dfile));
$fp = fopen($dfile, 'r');
while(connection_status() == 0 && $buf = @fread($fp, 8192)){
  echo $buf;
}
fclose($fp);
@unlink($dfile);
@flush();
@ob_flush();
exit();
?>