header function not working even after putting ob_start();

Question

Possible Duplicate:
Headers already sent by PHP

I have the following code in my php file. I want to redirect from this page using header function which is clear in code below. I have made sure that there are no echo commands and have also placed ob_start(); at the beginning of the file yet i am getting the following error:

Warning: Cannot modify header information - headers already sent by (output started at /hermes/bosweb/web054/b548/ipg.psdingcampsduscom/facebook_registration_plugin/store_user_data.php:1) in /hermes/bosweb/web054/b548/ipg.psdingcampsduscom/facebook_registration_plugin/store_user_data.php on line 171

here is the code :

<?php ob_start();
            define('FACEBOOK_APP_ID', 'xxxxxxxx');
            define('FACEBOOK_SECRET', 'xxxxxxxxxx');
            // No need to change function body
            function parse_signed_request($signed_request, $secret) {
                list($encoded_sig, $payload) = explode('.', $signed_request, 2);
                // decode the data
                $sig = base64_url_decode($encoded_sig);
                $data = json_decode(base64_url_decode($payload), true);
                if (strtoupper($data['algorithm']) !== 'HMAC-SHA256') {
                    error_log('Unknown algorithm. Expected HMAC-SHA256');
                    return null;
                }
                // check sig
                $expected_sig = hash_hmac('sha256', $payload, $secret, $raw = true);
                if ($sig !== $expected_sig) {
                    error_log('Bad Signed JSON signature!');
                    return null;
                }
                return $data;
            }
            function base64_url_decode($input) {
                return base64_decode(strtr($input, '-_', '+/'));
            }
            if ($_REQUEST) {
                $response = parse_signed_request($_REQUEST['signed_request'],
                                FACEBOOK_SECRET);
header("location: fbwe/step2.php?name=".$name."&email=".$email."&gender=".$gender."&arts=".$cb1."&act=".$cb2."&cooking=".$cb3."&dance=".$cb4."&designing=".$cb5."&fashion=".$cb6."&interior=".$cb7."&modeling=".$cb8."&photography=".$cb9."&poetry=".$cb10."&programming=".$cb11."&reading=".$cb12."&sketching=".$cb13."&singing=".$cb14."&sports=".$cb15."&stunting=".$cb16."&videography=".$cb17."&other=".$cb18);

                // Connecting to Database

            } else {
                //echo '$_REQUEST is empty';
            }
            ?>

Can anyone figure out what is wrong?

Sometimes it comes from the UTF8 BOM, check and see if it's there. — user703016, Jun 11 '12 at 09:16
I will bet a large amount of money on there being whitespace before your opening ` — DaveRandom, Jun 11 '12 at 09:17
All possible causes and their fixes are listed in [Headers already sent by PHP](http://stackoverflow.com/questions/8028957/headers-already-sent-by-php) — deceze, Jun 11 '12 at 09:17
@DaveRandom You were completely right ! It worked like a charm once i removed the spaces before — user1446599, Jun 11 '12 at 09:21

Pramod Kumar Sharma · Accepted Answer · 2012-06-11T10:13:19.743

0

Few things that should be keep in mind before using header function.

There should be no echo or print statement before the header function.
There should be no space on top and bottom of the page i.e page should start with <?php and end with ?>. There must be no blank space after or before these tags.

edited Jun 11 '12 at 10:13

answered Jun 11 '12 at 09:25

Pramod Kumar Sharma

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header function not working even after putting ob_start();

1 Answers1