my $fsize = -s "$file";
$|++;
open(my $fh,"$f->{upload_dir}/$file") || die"Can't open source file";

print qq{Content-Type: application/octet-stream\n};
print qq{Content-length: $fsize\n};
#print qq{Content-Disposition: attachment; filename="$fname"\n};
print qq{Content-Disposition: attachment\n};
print qq{Content-Transfer-Encoding: binary\n\n};

$speed = int 1024*$speed/10;
my $buf;
while( read($in_fh, $buf, $speed) )
{
   print $buf;
   select(undef,undef,undef,0.1);
}