sub write_and_download{

	[...]

	$self->generate_zip();

	$self->download_file();

	my $filename = "temporary/" . $projectname . ".zip";
	unlink $filename;

};

sub download_file{
my $self = shift;
	my $downloadfile = $projectname . ".zip";
	my $fullpathdownloadfile = "temporary/$downloadfile";
	my $output = '';
	my $buffer = '';
	open my $fh, '<', $fullpathdownloadfile
	  or return error_handler("Error: Failed to download file <b>$downloadfile</b>:<br>$!<br>");

	while (my $bytesread = read($fh, $buffer, 1024)) {
	  $output .= $buffer;
	}

	close $fh
	  or return error_handler("Error: Failed to download file <b>$downloadfile<b>:<br>$!<br>");

	my  $downloadfilesize = (stat($fullpathdownloadfile))[7]
	  or return error_handler("Error: Failed to get file size for <b>$downloadfile<b>:<br>$!<br>");
	  
	$self->header_props(
						'-type'                => 'application/x-download',
						'-content-disposition' => "attachment;filename=$downloadfile",
						'-content_length'      => $downloadfilesize,
					   );
	return $output;
};