远程下载 PHP下载远程文件到本地存储的代码

<?php 
function GrabImage($url,$filename="") {
    if($url=="") return false;
    if($filename=="") {
        $ext=strrchr($url,".");
        if($ext!=".gif" && $ext!=".jpg") return false;
        $filename=date("dMYHis").$ext;
    }
    ob_start();
    readfile($url);
    $img = ob_get_contents();
    ob_end_clean();
    $size = strlen($img);
    $fp2=@fopen($filename, "a");
    fwrite($fp2,$img);
    fclose($fp2);
    return $filename;
}
function gethttpimage($url){  
    if(!empty($url)){  
        $filename=uniqid().strrchr($url,".");  
        echo $filename;
        $get_file=@file_get_contents($url);   
        if($get_file){  
            $fp=@fopen($filename,"w");  
            @fwrite($fp,$get_file);  
            @fclose($fp);  
        }   
        return $imgUrl;  
    }else{  
        return false;  
    }   
}  
//$img=GrabImage("http://s15.sinaimg.cn/middle/46f37fb5g93953685ea0e&690.jpg","");
$img=gethttpimage("http://s15.sinaimg.cn/middle/46f37fb5g93953685ea0e&690.jpg","");
if($img) echo '<pre><img src="'.$img.'"></pre>';
else echo "false";
?>