php 批量下载图片的一个小程序

<?php

$url = "http://photo.hupu.com/nba";
$content=file_get_contents($url);
$reg="/<img.*?src=\"(.*?)\".*?>/";

preg_match_all($reg,$content,$matches);

$path = './imgDownload';
if(!file_exists($path)){
mkdir($path, 0777);
}

for($i = 0;$i < count($matches[1]);$i ++){

/*explode
$url_arr[$i] = explode('/', $matches[1][$i]);
$last = count($url_arr[$i])-1;
*/

//strrchr
$filename = strrchr($matches[1][$i], '/');

downImage($matches[1][$i],$path.$filename);
//downImage($matches[1][$i],$path.'/'.$url_arr[$i][$last]);
}

function downImage($url,$filename="") {
if($url=="") return false;

if($filename=="") {
$ext=strrchr($url,".");
if($ext!=".gif" && $ext!=".jpg" && $ext!=".png" && $ext!="jpeg") return false;
$filename=date("YmdHis").$ext;
}

ob_start();
//make file that output from url goes to buffer
readfile($url);
//file_get_contents($url);  这个方法不行的！！！只能用readfile
$img = ob_get_contents();
ob_end_clean();

$fp=@fopen($filename, "a");//append
fwrite($fp,$img);

fclose($fp);

return $filename;
}