关于批量下载ftp服务器的文件的方法

前言：批量下载网上有一堆，但是无奈都基本是对自己项目作用不大，研究了一下，分享和记录

1.首先要知道这个是从html页面发起的所以必须要加入这段话才行

//之前尝试用ajax和layer弹层来实现发现都会产生错误因此必须要用这个方法才行，前端的方法

location.href = 你想要访问的.php网页;

//后端的实现方法

<?php
//这个class类是借鉴网友的，具体内部逻辑我也不太清晰，所以。。。。。。。
class zipfile {
    var $datasec = array ();
    var $ctrl_dir = array ();
    var $eof_ctrl_dir = "x50x4bx05x06x00x00x00x00";
    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 = "x50x4bx03x04";
        $fr .= "x14x00";
        $fr .= "x00x00";
        $fr .= "x08x00";
        $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 = "x50x4bx01x02";
        $cdrec .= "x00x00";
        $cdrec .= "x14x00";
        $cdrec .= "x00x00";
        $cdrec .= "x08x00";
        $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)) . "x00x00";
}

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);
}
}

$id_link = isset($_GET["id_link"]) ? $_GET["id_link"] : ""; //接收前端的get传值

//下面是数据库的操作，根据自己的连接数据库来具体操作
$sql = "
select t.`id_attachment`,t.`path`,t.`type`,t.`name`,t.`suffix`,t.`size` from t_attachment t 
where 1=1 and t.delete_flag='0' and t.`id_link`=:id_link;
";
$bindings = array(
    ['key' => ':id_link', 'val' => $id_link, 'type' => PDO::PARAM_STR]
);
//ftp连接登录信息
$ftp_user = $ftp_details["user"];
$ftp_pass = $ftp_details["pass"];
$ftp_host = $ftp_details["host"];
//下面是实例操作过程：
$dfile = tempnam('/tmp', 'tmp');//产生一个临时文件，用于缓存下载文件
$zip = new zipfile();
//----------------------
$filename = 'image'.md5('trejlifd098498534'.rand(1000,9999)).'.'.'zip'; //下载的默认文件名

//以下是需要下载的图片数组信息，将需要下载的图片信息转化为类似即可
$image = array();
for ($i=0;$i<count($results);$i++){
$ftp_path = $results[$i]["path"]."/".$results[$i]["id_attachment"];
$image[$i]['image_src'] = "ftp://{$ftp_user}:{$ftp_pass}@{$ftp_host}{$ftp_path}";
$image[$i]['image_name'] = 'img'.$i.'.'.$results[$i]["suffix"];
}

foreach($image as $v){
$zip->add_file(file_get_contents($v['image_src']), $v['image_name']);
// 添加打包的图片，第一个参数是图片内容，第二个参数是压缩包里面的显示的名称, 可包含路径
    // 或是想打包整个目录 用 $zip->add_path($image_path);
}
//----------------------
$zip->output($dfile);

// 下载文件
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="'.$filename.'"'); //设置下载的默认文件名
header('Content-length:'. filesize($dfile));
$fp = fopen($dfile, 'r');
while(connection_status() == 0 && $buf = @fread($fp, 8192)){
echo $buf;
}
fclose($fp);
@unlink($dfile);
@flush();
@ob_flush();
exit();

以上方法你肯定不是拿来就能用的，需要自己去看看每一行的代码注释，修改下参数