This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 4 years ago.
Php Doc Says:
"Remember that header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from
PHP."
" This requires that you place calls to setcookie() prior to any
output, including and tags as well as any whitespace."
I understand the importance of above mentioned requirements but how is the code below running without throwing "Headers already Sent" error?
<html>
<body>
<h1>Hey</h1>
<?php
echo "Hello";
setcookie("hey","hellocookie");
//header("Pragma: no-cache");
//echo $_COOKIE['hey'];
header('Location: http://www.example.com/');
?>
</body>
</html>
header('Location: http://www.example.com/'); works without throwing
errors. Also, setcookie("hey","hellocookie"); works even though
there's an output echo "Hello"; prior to it.
I tested it with echo $_COOKIE['hey']; and it does print
heycookie.
*Note: Running the above script on Localhost/Xampp. Error Reporting is not disabled. I do get an error on browser output if I miss one of those semi-colons. *
Any of those functions that works with headers MUST be used before any kind of output is sent... even single white space raise such PHP error.
PHP header() documentation
Related
This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 4 years ago.
I try to use ob_start() ob_end_flush(); to hide the errors. Is there no other way to fix this Cannot modify header information?
echo $claim_url;
require_once $_SERVER['DOCUMENT_ROOT'] . '/auto-faucet/lib/shortlink.php';
$claim_url = shortlink_create($claim_url);
header('Location: ' . $claim_url, true, 303);
Before header there should not be anything in the output.
Remove echo $claim_url;
Remember that header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from PHP. It is a very common error to read code with include, or require, functions, or another file access function, and have spaces or empty lines that are output before header() is called. The same problem exists when using a single PHP/HTML file.
Documentation
NOTE: use die() or exit() after redirect.
This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 8 years ago.
I can't use header() in any page where the session_start() is running. When I use it it says
Can't modify header information already sent by (...)
Can anyone help me for this issue?
you're printing something to the http stream before you call header. You can't do this you need to call header before any printing/echoing is done.
You may be getting a warning from your session_start if that's the only thing in your code, try and suppress warnings so it does not show anything else besides code output:
error_reporting(E_ERROR | E_PARSE);
Otherwise just do as others have said and make sure your code isn't outputting anything before the header is changed.
This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 9 years ago.
The Insert works perfectly as tested that without the header redirect.
My problem is i'm using MYSQLI with Object oriented approach and still new to it. When i have the header redirect in there it tells me in the browser
"Warning: Cannot modify header information - headers already sent by
(output started at /home/hawkwsco/public_html/admin/include/template/doc.inc.php:1)
in /home/hawkwsco/public_html/admin/include/library/functions/process/process.inc.php on line 10"
My code is below:
<?php
require ($_SERVER['DOCUMENT_ROOT'].'/admin/include/config/config.inc.php');
$query = ("INSERT INTO page(pa_id, pa_page, pa_page_info) VALUES ('NULL', '{$_POST['page']}', '{$_POST['info']}')");
$mysqli->query($query);
header("Location: http://".$_SERVER['SERVER_NAME']."/admin/content.php");
exit;
?>
What am I doing wrong?
Most likely the file you are including has some text in it being output (even a newline at the end of the file is enough) causing the output to start before the header can be sent. I usually make sure my includes do not have a ?> at the end to avoid this problem.
Alternatively, you can use output buffering (ob_start()) to avoid any output being sent until you are ready. ob_start() must be called before any output to be effective.
This question already has answers here:
PHP form to email data AND take the user to a "thank you" page [duplicate]
(5 answers)
How to fix "Headers already sent" error in PHP
(11 answers)
Reference - What does this error mean in PHP?
(38 answers)
Closed 9 years ago.
Is there any better way to redirect because I get this error:
Warning: Cannot modify header
information - headers already sent by
(output started at
C:\xampp\htdocs\falco\index.php:26) in
C:\xampp\htdocs\falco\classes\controller.php
on line 306
Very often by using header("Location: blablabla.php?id=3")
Is there any other way to redirect and not get this error? or maybe I am doing something wrong?
THANK YOU FOR YOUR TIME.
You have to do header changes before any content on your page (also whitespace I think). So place the header function at the very top of your page.
This is a warning, not an error. It occurs because the headers were already sent to the browser. Make sure, that you don't have any output in your PHP file before modifying the header. This includes echo, print_r and also whitespaces before your intial <?php tag.
Headers need to appear before the body of your response. Therefore, if you have anything echo'd (including whitespace) and then attempt to send a header, it will fail.
Leave output for the very last thing in PHP.
You are printing headers after you've printed something else. The first method is just what you're doing, but you will have to wait with printing anything else until you know whether you want to redirect or not. You can use the output buffering functions if you absolutely must print before that. ob_start at the beginning to "pause" printing, then print the header, then call ob_end_flush to print everything that was held back.
Second method is inserting this into the <head>, but this too is timing-specific - you can't just insert it anywhere in the document.
<meta http-equiv="refresh" content="0; url=http://www.example.com/"/>
Third method, stick this script anywhere - but this forces the client to have scripts allowed, or nothing happens:
<script> location.replace('http://example.com'); </script>
You must have some whitespace or other output before you call header() which is triggering this warning. See the manual:
Remember that header() must be called
before any actual output is sent,
either by normal HTML tags, blank
lines in a file, or from PHP. It is a
very common error to read code with
include(), or require(), functions, or
another file access function, and have
spaces or empty lines that are output
before header() is called. The same
problem exists when using a single
PHP/HTML file.
This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 2 years ago.
Possible Duplicate:
Headers already sent by PHP
Getting the following error:
"Warning: Cannot modify header information - headers already sent by (output started at..."
for the following line:
echo '<center>Current Time is '. gmdate("H:i A") . ' GMT (Greenwich Mean Time or UTC)<br />';
If I comment it out it just throws up the error at the next echo statement. Thoughts on why PHP hates my echo statements so much?
Here is my include toward the bottom of the HTML:
<div id="saveCanForm" width="100%">
<?php include('savereport.php'); ?>
</div>
It's not the echo statements that are the problem. It looks like you have a header call somewhere later in the file, but you can't send headers once you output any text at all. You could either move the headers to the beginning of the script or alternatively use output buffering.
Because our echos are coming before you are sending the header which is not allowed. Ensure that header go before any of your output.
If you don't want to rearrange you can also use output buffering.
Headers are dealt with before there is any other output, so if you write something out then PHP can't properly send headers afterwards. At some point in your code you are giving HEAD instructions which hence fails. (There's technical reasons for this, like redirects and so forth)
Its not the echo which is the problem. It is most probably caused by a file that you have included in the .php file. Have you included a file at all? This will probably be at the top. If you included file statement is not at the top of the file make sure it is.