save generate pdf to server - php

Question

I am developing an application and I need to create pdf files. using pdfbundle
public function helloAction($id)
{
$format = $this->get('request')->get('_format');
$venta = $this->getDoctrine()->getRepository('miomioBundle:Venta')->find($id);
$lineas = $venta->getLineas();
$cliente = $venta->getCliente();
$empleado = $venta->getEmpleado();
//return new Response ($cliente->getNombre());
$pdf = $this->render(sprintf('miomioBundle:Venta:helloAction.%s.twig', $format), array('cliente' => $cliente,'empleado' => $empleado,
'venta' => $venta,
'lineas' => $lineas
));
$hi = "hiii";
//file_put_contents('holajiji.pdf', $pdf);
file_put_contents( 'hi.txt', $hi);
return $pdf;
}
The function generates the txt file correctly but when I try to do the same with the pdf I displayed a lot of other odd characters.
%PDF-1.4 %���� 1 0 obj <> endobj 2 0 obj <> endobj 3 0 obj <> endobj 4 0 obj [] endobj 5 0 obj <> endobj 6 0 obj <> endobj 7 0 obj <> /XObject <> >> /MediaBox [0 0 595 842 ] /Contents [8 0 R ] /Parent 2 0 R >> endobj 8 0 obj <> stream /F1 9 Tf 0 g 0 G q 0.69 0.878 0.9020000000000000 RG 0.69 0.878 0.9020000000000000 rg 39 586 m 93.25 586 l 93.25 570 l 39 570 l 39 586 l h f Q q 1 0.753 0.796 RG 1 0.753 0.796 rg 447.5 586 m 501.75 586 l 501.75 570 l 447.5 570 l 447.5 586 l h f Q q 0.69 0.878 0.9020000000000000 RG 0.69 0.878 0.9020000000000000 rg 501.75 586 m 556 586 l 556 570 l 501.75 570 l 501.75 586 l h f Q q 0.9020000000000000 0.9020000000000000 0.98 RG 0.9020000000000000 0.9020000000000000 0.98 rg 39 432 m 142.4 432 l 142.4 416 l 39 416 l 39 432 l h f Q q 0.9020000000000000 0.9020000000000000 0.98 RG
if open witch text editor the archive generate :
HTTP/1.0 200 OK
Cache-Control: no-cache
Content-Type: text/html; charset=UTF-8
Date: Tue, 06 Nov 2012 12:59:43 GMT
<pdf>
<page document-template="holita.pdf">
<img src="/var/www/Symfony/src/mio/mioBundle/Resources/public/images/optinet.png" float="left" height="100px" width="300px" />
<h1 float="right" text-decoration="underline">Factura Número: 4</h1>
<p><h1 float="right">Fecha: 06/11/2012 </h1></p>
<table text-align="left" margin-bottom="30%">
<tr>
thanks.

Answer 1

Try to output headers to let browser know that you are outputting PDF file:
Header('Content-Type: application/pdf');

Answer 2

solved the problem witch section in github psliwa thanks