PHP 下载远程文件

if ($_GET[xfer]) {
if ($_POST[from] == "") {
print "You forgot to enter a url.";
} else {
copy("$_POST[from]", "$_POST[to]");
$size = round((filesize($_POST[to])/1000000), 3);
print "transfer complete.

$_POST[from]

$_POST[to] : $size MB";
}
} else {
print "
from(http://): 

to(filename): 


";
}
?>

PHP