Download a remote file via URL?

By calling wget?

[iProgram]

I have a web interface which lets users to upload files. Alternatly, I also want to let users to retrieve files remotely. For example, there is a PDF file at http://www.example.com/test.pdf, a user can provide this URL and press a button, and then a PHP script downloads this remote file to my server. So is there a stable script which can do this for me?

If I do this by myself, I will use exec('wget http://www.example.com/test.pdf --output-document=something.pdf'), is this reliable enough?

[mcavic]

Yes, wget is reliable. But remember to check the URL that the user enters to be sure it's safe. In particular, you should reject it if it contains any of ; ' " < > ( ) { } \

Also, PHP has a built-in version of Curl. It's the same basic idea as wget, and the built-in version takes more work to use, but is probably more robust.

[iProgram]

Thanks!

[tata668]

copy [ca3.php.net] works with URLs...

[vincevincevince]

You can also (if need be) do this:

$destination=fopen("files/localfile.dat","w");
$source=fopen($url,"r");
while ($a=fread($source,1024)) fwrite($destination,$a);
fclose($source);
fclose($destination);

The advantage of this method is that you can enforce maximum upload sizes without having to download everything before you check for the file size:

$destination=fopen("files/localfile.dat","w");
$source=fopen($url,"r");
$maxsize=3000;
$length=0;
while (($a=fread($source,1024))&&($length<$maxsize)) 
{
$length=$length+1024;
fwrite($destination,$a);
}
fclose($source);
fclose($destination);

Imagine your server has 3Gb space free and someone supplies you a 3.1Gb file by URL. Your server is going to have serious problems pretty soon if you just eat it all and then check.