I can i fix this session start error

[simon2x1]

I do not understand these error and also i can i fix it.
This is the error- error:warning: session_start()[function.session-start]:cannot send session cache limiter - header already sent (output started at /home/alinkene/public_html/simpleimage.php:66) in /home/alinkene/public_html/user.php on line 4

<?php
require_once("connect.php");
include('simpleimage.php')
if (! isset($_SESSION['user'])){
header ('location: home.php');
}
 
//my other code
 
?>
 

[Samishii23]

To use sessions with PHP scripts, you must put session_start(); into your code.

<?php
session_start();
include('simpleimage.php')
if (! isset($_SESSION['user']))header ('location: home.php');?>

If that doesn't work, then you need to check if your website servers PHP config is set to allow sessions.

http://us.php.net/manual/en/function.session-start.php

[simon2x1]

I included session_start(); in my code in line 4 when got the error i forgot put it when i was posting my question how can i check if my website server php config is set to allow session i need you to show me how and if not set how can i set it.

[Dormilich]

@simon2x1
that means that you send content (an image?) before session_start() is called. which causes the error.

[simon2x1]

Please explain that better i do not think i have send content(image) let me assume so i can i fix the error, the fun thing is that i did not get these error when i was testing it on wamp server it was when i was now testing it on my web server. i need fix it before i present to my project coordinator

[Dormilich]

@simon2x1
I can only judge from the message and that states, that before session_start() was called either some content (text, image) or a header (via header()) was sent (in file simpleimage.php on line 66).

[simon2x1]

I have the header( present in both the home page(home.php) and the login page(the page where the error appear) what should i then do should i remove the header() and if i remove it i hope it will not affect the login page and the error will to be fixed.

[Atli]

Hey.

You can not use the session_start or header functions once you have started to add content to the page.
By that I mean: you must call the function before any part of the page is added. This includes any HTML or text. Even a white-space before the <?php counts.

The best way to fix these sort of errors is to make sure that no content is added before the function is called. If that is not possible, you can have PHP buffer the output and only send it when you allow it, thus allowing you to call the functions at any time.

You can read more about how that works in the manual: PHP: Output Control - Manual

[simon2x1]

what do you mean by no content must be added before the function is called.is it that i should remove header function which i have done but it still give me the same error.this is my code below i will appreciate it if you will help me edit the error on my code i have two pages home.php and login.php it is the login.php that display the error.

error - Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/alinkene/public_html/SimpleImage.php:66)
in /home/alinkene/public_html/admin_compile.php on line 5

login.php

<?php
require_once("connect.php");
include('SimpleImage.php'); ------ this reduce image
session_start();
 
if (!isset($_SESSION['user_id'])){
 header ('location: home.php');
}
 
if (isset($_POST['submit'])) {
if(empty($_POST['companyname']) OR empty($_POST['companyemail'])){
    echo '<font size="2" color="#8B1601">You haven\'t filled in all the fields. Please do it again.</font>';
 }else {
$companyname = ($_POST['companyname']);
$companyemail = ($_POST['companyemail']);
mysql_query("INSERT INTO company
(cname, cemail) VALUES
('" . $companyname . "', '" . $companyemail . "')") or die(mysql_error());
    }
}
?>

home.php

<?php
require_once("connect.php");
session_start();
 
 
if(isset($_POST['submit'])){
$username = mysql_real_escape_string($_POST['username']);
$password = md5($_POST['password']);
 
$query = mysql_query("SELECT id FROM login WHERE username = '" . $username . "' 
     AND password = '" . $password . "'") or die(mysql_error());
 
list($user_id) = mysql_fetch_row($query);
 
 
if(empty($user_id)) {
 echo 'No combination of username and password found.';
}else{
 
$_SESSION['user_id'] = $user_id;
header('location: login.php');
    }
}
 
<form method="post" action="home.php">
 
Username: <input type="text" name="username"><br>
<br>
Password: <input type="password" name="password"><br>
<br>
<input type="submit" value="Login!">
 
</form>
?>
 
 
 
 
 
 

[Dormilich]

do this

<?php
session_start();
require_once("connect.php");
include('SimpleImage.php'); ------ this reduce image
…

…I wonder why you didn’t try that yet, it was the first thing proposed to solve the issue…

[Atli]

@simon2x1

<?php
echo "This will cause an error";
session_start();
?>

<p>And so will this</p>
<?php
session_start();
?>

<?php
session_start();
echo "This will work.";
?>

The same goes for the header and setcookie functions.

Just think of it this way.
When your server sends the page to your users, before it can send the actual page it sends a bunch of info about what it is about to send. Those are the headers.
So if you want to send a header, which the session_start, setcookie and header functions do, you must do so before you start sending the actual page.

Once you start sending the page, it is to late to try to send a header.