How to resolve Warning "Cannot modify header information" in page redirect

Question

Possible Duplicate:
“Warning: Headers already sent” in PHP

I have following piece of code to do the 301 redirect at the top without any spaces and nothing above this code, but its giving the error,

Warning: Cannot modify header information - headers already sent by

<?php
   require_once('../../config.php');
   header("HTTP/1.1 301 Moved Permanently");
   header("location: http://www.myapp.com/courses/mycourse-new.php");
?>

I tried using ob_start, but didn't work. I have done 301 for many files without any issues. how to resolve this issue.

Do you still have the message when commenting out the `required_once` ? — Pierre de LESPINAY, Nov 30 '12 at 10:29
If this doesn't have whitespace, then `config.php` probably does... — MrCode, Nov 30 '12 at 10:34
is there a particular reason you are using PHP4 (which isn't supported anymore since 2008)? — Gerald Schneider, Nov 30 '12 at 10:36

score 3 · Answer 1 · answered Nov 30 '12 at 10:34

3

Make sure you have absolutely no output character (not even a blank or newline) before the <?php, both in your file and in the included file.

answered Nov 30 '12 at 10:34

Gerald Schneider

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just adding to what Gerald Schneider said ... please note, This output character even means a space before php – Oxi Nov 30 '12 at 11:20

score 0 · Answer 2 · answered Nov 30 '12 at 10:32

0

Are you using ob_start() on the first line of your code (before html tag)?

answered Nov 30 '12 at 10:32

Žan Kusterle

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I know, but it depends on what he needs – Žan Kusterle Nov 30 '12 at 10:41

score 0 · Answer 3 · answered Nov 30 '12 at 10:34

0

You may disable output buffering with

ini_set('output_buffering', 0);

in you PHP file or set

output_buffering = Off

in php.ini and everything will work fine.

answered Nov 30 '12 at 10:34

Rodion Baskakov

636
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score 0 · Answer 4 · edited May 23 '17 at 11:43

0

Try it after removing the closing php tag ?>
Why do some scripts omit the closing php tag '?>'?
PHP closing tag

edited May 23 '17 at 11:43

Community

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answered Nov 30 '12 at 10:34

Nandakumar V

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score -1 · Answer 5 · edited Nov 30 '12 at 10:40

-1

Use ob_start() like...

`<? 
       ob_start();
       require_once('../../config.php');
       header("HTTP/1.1 301 Moved Permanently");
       header("location: http://www.myapp.com/courses/mycourse-new.php");`

Ob_start will buffer all output untill script exit() and buffer releases. To redirect using header there should not be any other header sent already.

Alternatively you can change if you have space before

edited Nov 30 '12 at 10:40

iLaYa ツ

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answered Nov 30 '12 at 10:36

Mahesh Chavda

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Using the output buffer is a nasty hack to remove the symptom, it doesn't fix the cause of the problem. – Gerald Schneider Nov 30 '12 at 10:42
But helpful in case user has to quick fix the issue for large source code until he/she finds exact issue. – Mahesh Chavda Nov 30 '12 at 10:45
If you use this "quick fix" you'll never find the issue – Gerald Schneider Nov 30 '12 at 10:46

How to resolve Warning "Cannot modify header information" in page redirect

5 Answers5