$filename =~ /\.(gif|jpg|jpeg)$/

##</code><code>##

-s $file

##</code><code>##

open(OUT, ">$upload_dir/$filename") || die print "Fail to upload: $!"; 
while(<$file>) {
        print OUT;
}
close(OUT);

##</code><code>##

{
   local *OUT; # Or better yet use lexical filehandle!
   open(OUT, ">$upload_dir/$filename") or die "Fail to open $filename: $!"; 
   binmode(OUT);
   local $/=\1024; # A block at a time
   local *_; # Don't stomp on $_
   while(<$file>) {
        print OUT;
   }
   close(OUT) or die "Error writing $filename: $!";

}