Cannot send session cookie - headers already sent by [duplicate] - php

This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 9 years ago.
I've a php script the first thing in the code is session_start();, but I keep receiving this error
Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/****/public_html/admincp/index.php:1) in /home/****/public_html/admincp/index.php on line 1
but the script works great in the localhost.
<?php session_start();?>
<?php
require 'global.php';
?>
<?php
//check if the user logged in
if(!isset($_SESSION['user_id']))
page_redirect('login.php'); // go to login.php.
?>

Open the file in your favorite text editor and convert the file to UTF8 without BOM.
Annoying error, once did the same thing.

A lot of times a lone whitespace character at the top of the file can cause this error, because the whitespace character gets output. Make sure that there's nothing above that <?php session_start(); ?>, not even a whitespace character. If the host you're on has an auto_prepend_file, that could also throw it off.

Related

Warning: Cannot modify header information - headers already sent by php error [duplicate]

This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 9 years ago.
After I changed something in my .php file my whole site got an error. I changed the file back to the old one but now I get this error at the top of my page:
Warning: Cannot modify header information - headers already sent by
(output started at
/home/test/domains/test.nl/public_html/wp-content/themes/mugen/engine/theme-scripts.php:1)
in
/home/test/domains/test.nl/public_html/wp-content/plugins/woocommerce/classes/class-wc-session-handler.php
on line 63
The plugin is Woocommerce but it was working before with the same code but now I keep getting this error at the top.
Code of the file I changed aka the theme-scripts.php file:
http://pastebin.com/mU4DNLnm
How did you edit the file? I'd guess you now have a Unicode Byte Order Mark at the beginning of it. Can whatever editor you used save the file with the option "without BOM"? Most decent ones can.
The big clue here is that your error comes from line 1, and line one of your file is just:
<?php
...which is an indicator that there may be something "invisible" right at the start of the file.
This error normally means you have already 'print'ed or 'echo'ed some text before php trying to write into the header info.

How to Remove this Error in php website [duplicate]

This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 8 years ago.
Error is:
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/gopal/public_html/Update.php:1) in /home/gopal/public_html/Update.php on line 2
Quick hack? Use Output control.
However, what you really should be looking for is any kind of content that has been rendered before session_start has been called. This method should be the second line of code in your application:
<?php
session_start();
/* rest of site */
"headers already sent" this means that a script outputs to browser something (a space, a character or a BOM element)
make sure your includes files do not echo anything.
If that is verified and you still get the message, then i guess it's a BOM element (usually in utf-8 encoded documents/pages)

header has error in php , why? [duplicate]

This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Cannot send session cookie - headers already sent
Headers already sent by PHP
My previous problem was for UTF-8 but now ! again my code generates this error :
Warning: Cannot modify header information - headers already sent by (output started at F:\xampp\htdocs\1\error_list.php:34) in F:\xampp\htdocs\1\error_list.php on line 75
why?
my code is :
header("location:list.php?msg=Please enter some username and password");
There are several things 'wrong' with your code:
Don't use shorttags. They aren't really wrong but I don't like them :)
I think your define should be: define('ADMIN', $_SESSION['name']);
You problem either comes up because there is already some html or anything (space) outputted to the browser. If you have saved the file as UTF-8 you should make sure it doesn't include a BOM
This happen when you send html code even a single space to the browser. If you have any html code before this php code, so that the problem.
Solution
To tell the browser to buffer everything except php codes, you need to use:
ob_start();
when browser read the the function, it will buffer everything and never send it to the browser until your php code has done its task.
EDIT
Well, If you have some html code before your php code, what do you wanna do? Is there any thing you can do?
This a workaround for the problem, why not???

[PHP]Warning: Cannot modify header information [duplicate]

This question already has answers here:
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.
I have a simple code:
header("Location: http://www.wp.pl/");
end this code return:
Warning: Cannot modify header information - headers already sent by (output started at /var/www/plik.php:1) in /var/www/plik.php on line 2
I don't have any BOM, whitespaces etc. before "php" declaration.
What's wrong?
Clearly, you do have something sent already, but you can get around this by wrapping the PHP script in ob_start() / ob_end_flush().
1) Is that the only content on your page?
2) Is that script being included on a different page?
This warning is because when you write anything to the file, that is not the header, you cannot write to the header anymore. The header tells the script where to put its output, and if the header has been modified after content is written, then there is not guarantee of where it should put that content (as I understand it)
If this is not the only content on the page, check if anything above it is throwing an error or displaying anything.
If this is being included on a different page, check if that other page might be displaying something or throwing a warning/error.
Double check that there are no spaces or new lines after the closing php tag ?>. If there is, those spaces or new-lines get output to the browser, and since there is already output, you can't modify the header. A good practice is to just never include the closing php tag in your php files to prevent this from happening.

Warning: Cannot modify header information. Can't find error [duplicate]

This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 9 years ago.
I'm using a login-script and on my developmachine it worked perfectly but when I moved it to my webhost it stopped working.
The code can be viewed here: http://beta.yapaste.com/fm
The error I get when I login is
Warning: Cannot modify header information - headers already sent by (output started at /*/*/*/*/*/*/login.php:10) in /*/*/*/*/*/*/inc/login.php on line 43
But I can't find the error.
Thanks for answers, Victor.
Edit: Found the error, I included the file that I've got on yapaste in another file so the php-code wasent first.
On line 10 of login.php something is sent to the browser (white space between ?> and <?PHP tags count), at which point headers must be sent to. This triggers a warning when you try to then add more headers after this, on line 43.
You need to have a look at line 10 and prevent the output being sent, or use output buffering - your previous host could have had this on by default which might explain why it no longer works...
use ob_start(); at entry of your script to start buffering, but as Simon said, propably there is some white space wich is sended to browser befor you try to change headers.
Remeber, that you can omit ending php tag if you don't have any output code after, That will secure you from white spaces at end of file.
Also check for format of your source files - if they are encoded in UTF-8 with BOM, there are some starting characters that could be not shown in editor at beginning of the file.

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