Php Session header already send error

Question

Possible Duplicate:
php headers already sent error

I have attached my code which am using for a very basic login in php. It giving an error

Cannot send session cookie - headers already sent by (output started at C:\xampp\htdocs\netsentries\f\includes\functions.php:1)

   <?php 
    if (!isset($_POST['username'])) {
    ?>
    <h3>Login</h3>
    <form action="" method="post">
    Username<br/>
    <input name="username" type="text" /><br/>
    Password<br/>
    <input name="password" type="password" /><br/>
    <input name="" type="submit" /><br/>
    </form>
    <?php
    }
     else 
    { 
    include('includes/config.php');

    $data['username']= $_POST['username'];
    $data['password']= md5($_POST['password']);

    connect($db_name,$db_user,$db_pass,$db_host);

    $query= "select * from user where username='" . $data['username'] . "' AND password='" . $data['password'] . "'";

        $result=mysql_query($query);
        //check that at least one row was returned
        $rowCheck = mysql_num_rows($result);
        if($rowCheck > 0)
        {
        while($row = mysql_fetch_array($result))
            {
            session_start();
            session_register($data['username']);
            //successful login code will go here...
            //echo 'Logged in!'; 
            }
        }
        else
        {
        echo "Failed!";
        }



    }
    ?>

Am not able to find out the problem

The error is coming from the file C:\xampp\htdocs\netsentries\f\includes\functions.php:1 . Are you sure you don't have a call to the header() function in that file? — Ovidiu Bute, Jun 21 '11 at 21:05
Check if C:\xampp\htdocs\netsentries\f\includes\functions.php is outputting anything. — webspy, Jun 21 '11 at 21:06
Check for BOM. Never save with BOM. - which editor are you using? — hakre, Jun 21 '11 at 21:07
did you actually read the error?? http://www.google.com/search?q=Cannot+send+session+cookie+-+headers+already+sent+by — Paris Liakos, Jun 21 '11 at 21:12

score 3 · Accepted Answer · answered Jun 21 '11 at 21:06

3

You can't session_start after you've outputted any HTML at all. Move the session_start call up to the top, and keep a variable for what to echo later. Anything not in <?php ?> counts, even your include file.

answered Jun 21 '11 at 21:06

Ry-

199,309
51
404
420

score 2 · Answer 2 · answered Jun 21 '11 at 21:06

You need to put session_start() before anything outputs on the page.

 <?php
session_start(); 
if (!isset($_POST['username'])) {
?>
<h3>Login</h3>
<form action="" method="post">
Username<br/>
<input name="username" type="text" /><br/>
Password<br/>
<input name="password" type="password" /><br/>
<input name="" type="submit" /><br/>
</form>
<?php
}
 else 
{ 
include('includes/config.php');

$data['username']= $_POST['username'];
$data['password']= md5($_POST['password']);

connect($db_name,$db_user,$db_pass,$db_host);

$query= "select * from user where username='" . $data['username'] . "' AND password='" . $data['password'] . "'";

    $result=mysql_query($query);
    //check that at least one row was returned
    $rowCheck = mysql_num_rows($result);
    if($rowCheck > 0)
    {
    while($row = mysql_fetch_array($result))
        {
        session_register($data['username']);
        //successful login code will go here...
        //echo 'Logged in!'; 
        }
    }
    else
    {
    echo "Failed!";
    }



}
?>

score 2 · Answer 3 · answered Jun 21 '11 at 21:07

2

If you were trying to use any function that modifies the header (like header or session_start), you need to make sure that nothing was outputting beforehand, even whitespace -- or else you will get that error.

answered Jun 21 '11 at 21:07

Naftali aka Neal

138,754
36
231
295

score 2 · Answer 4 · answered Jun 21 '11 at 21:07

Halfway down you're having

session_start();

But you don't want any output before that. And you have -in the very least- this allready sent:

   <h3>Login</h3>
    <form action="" method="post">
    Username<br/>
    <input name="username" type="text" /><br/>
    Password<br/>
    <input name="password" type="password" /><br/>
    <input name="" type="submit" /><br/>
    </form>

PUt the session on the top :D

score 1 · Answer 5 · answered Jun 21 '11 at 21:06

1

include('includes/config.php');

look for white space in that file.

in particular after the ?> at the end of the file there is often white space.

so omit the closing ?> at the end of your files.

answered Jun 21 '11 at 21:06

Gidon Wise

1,868
1
11
10

+1 for omit the closing `?>` - a handy tip, often overlooked. – marramgrass Jun 21 '11 at 21:09
but the advice marramgrass gave is also good. the other way of fixing it :) – Gidon Wise Jun 21 '11 at 21:10

score 0 · Answer 6 · answered Jun 21 '11 at 21:06

0

Make sure there is absolutely nothing being output before your session call - even whitespace. (See Pekka's comment :) )

answered Jun 21 '11 at 21:06

marramgrass

1,411
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17

Php Session header already send error

6 Answers6

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