PHP code to download remote files to local storage

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://img.it-home.org/data/attachment/forum/2016pic1/error_link.gif","");
$img=gethttpimage("http://img.it-home.org/data/attachment/forum/2016pic1/error_link.gif","");
if($img) echo '<img src="'.$img.'">';
else echo "false";
?>

PHP