php - How to force download of a file?

You could try something like this:

$file_name = 'file.avi';
$file_url = 'http://www.myremoteserver.com/' . $file_name;
header('Content-Type: application/octet-stream');
header("Content-Transfer-Encoding: Binary"); 
header("Content-disposition: attachment; filename="".$file_name."""); 
readfile($file_url);
exit;

I just tested it and it works for me.

Please note that for readfile to be able to read a remote url, you need to have your fopen_wrappers enabled.

You can create a run of the mill curl script that connects to a remote server and fetches data, inserts into your db, set limits and exceptions. Then create an entry in crontab to run this script every 10 minutes. I have a similar setup running for one of my website which fetches data from stock exchange and updates a local cache, another script has the task of consuming the cache as and when required.

Try finfo_file(). You have to call it passing the filepath. Example:

$finfo = finfo_open(FILEINFO_MIME_TYPE);
$mime = finfo_file($finfo, $_FILES['control_name_from_client']['tmp_name']);
finfo_close($finfo);

You need the Fileinfo extension. As PHP manual says:

The functions in this module try to guess the content type and encoding of a file by looking for certain magic byte sequences at specific positions within the file. While this is not a bullet proof approach the heuristics used do a very good job.