PHP cannot modify header

Question

I’m trying to solve a problem with PHP but I can’t find out where my mistake is. If someone can help me please write an answer.

PHP sends the following error message:

[26-Feb-2014 03:00:46 Europe/Berlin] PHP Warning: Cannot modify header information - headers already sent by (output started at /Applications/MAMP/htdocs/PressIn_21022014/includes/head.php:2) in /Applications/MAMP/htdocs/PressIn_21022014/recap_commande.php on line 41

when I click on valider_commande:

<?php
    session_start();
    if(isset($_SESSION['auth']) && $_SESSION['auth'] == true){
    $document = basename(__FILE__);
    $titre = "Espace Membre";
    include("includes/head.php"); 
?>


  <div class="background col-xs-12 col-sm-12 col-md-12 col-lg-12">
            <div class="container top">
            <div class="elements">
              <form  id="form_top_ten" method="POST" action="recap_commande.php">
                    <div class="row">
                        <div class="col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Veste</h4></div>
                                      <img src="img/icone_veste.svg" />
                                      <button id="moins_veste" type="button" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                      <span class="quantite" id="top_ten_nb_veste">1</span>
                                      <button id="plus_veste" type="button" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                      <div class="prix"><span class="prix_pantalon">  10</span> €</div>
                                </div>
                        </div>
                        <div class="col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Pantalon</h4></div>
                                    <img src="img/icone_pant.svg" />
                                    <button id="moins_pantalon" type="button" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_pantalon">1</span>
                                    <button id="plus_pantalon" type="button" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_pantalon">  10</span> €</div>

                                </div>
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Chemise</h4></div>
                                    <img src="img/icone_chemise.svg" />
                                    <button id="moins_chemise" type="button" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_chemise">1</span>
                                    <button id="plus_chemise" type="button" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_pantalon">  10</span> € </div>

                                </div>
                        </div>
                        <div class="col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Robe</h4></div>
                                    <img src="img/icone_robe.svg" />
                                    <button id="moins_robe" type="button" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_robe">1</span>
                                    <button id="plus_robe" type="button" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_pantalon">  10</span> €</div>

                                </div>
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Manteau</h4></div>
                                    <img src="img/icone_manteau.svg" />
                                    <button id="moins_manteau" type="button" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_manteau">1</span>
                                    <button id="plus_manteau" type="button" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_pantalon">  10</span> € </div>

                                </div>
                        </div>
                        <div class="col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Veste</h4></div>
                                    <img src="img/icone_pant.svg" />
                                    <button type="button" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_veste">1</span>
                                    <button type="button" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_pantalon">  10</span> €</div>

                                </div>
                        </div>
                    </div>
                    <div class="row">
                        <div class="row col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Pull</h4></div>
                                    <img src="img/icone_pull.svg" />
                                    <button id="moins_pull" type="button" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_pull">1</span>
                                    <button id="plus_pull" type="button" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_pantalon">  10</span> €</div>

                                </div>
                        </div>
                        <div class="row col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Jupe</h4></div>
                                    <img src="img/icone_jupe.svg" />
                                    <button id="moins_jupe" type="button" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_jupe">1</span>
                                    <button id="plus_jupe" type="button" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_pantalon">  10</span> €</div>

                                </div>
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Draps</h4></div>
                                    <img src="img/icone_drap.svg" />
                                    <button type="moins_drap" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_drap">1</span>
                                    <button type="plus_drap" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_drap">  10</span> €</div>

                                </div>
                        </div>
                        <div class="col-xs-12 col-sm-6 col-md-6 col-lg-6">
                                <div class="commande_top_ten">
                                    <div class="col-xs-3 col-sm-4 col-md-4 col-lg-3"><h4>Chemise</h4></div>
                                    <img src="img/icone_chemisepliee.svg" />
                                    <button type="moins_drap" class="btn-moins btn-circle btn-mini"><i class="glyphicon-minus"></i> </button>
                                    <span class="quantite" id="top_ten_nb_drap">1</span>
                                    <button type="plus_drap" class="btn-plus btn-circle btn-mini"><i class="glyphicon-plus"></i> </button>
                                    <div class="prix"><span class="prix_pantalon">  10</span> €</div>
                                </div>
                        </div>
                    </div>

                    <button type ="submit" class="btn_valider btn btn-danger col-xs-9 col-sm-6 col-md-6 col-lg-4" name="valider_commande" value="valider_commande"><i class="glyphicon glyphicon-shopping-cart"></i>Valider commande (' .$prix_total. ' euros)</button>
                  </form>
                </div>
                </div>
                <?php
                  if (!empty($_SESSION['form_top_ten'])){
                      $nb_articles = sizeof($_SESSION['commande_top_ten']);
                      $prix_total = 0;
                      for ($i=0;$i<$nb_articles;$i++){
                        $prix_total += $_SESSION['commande_top_ten'][$i]['prix'];
                      }
                  }

                ?>
        </div>
  <?php 
      }
      else{
        header('Location:auth_form.php');
      }
    ?>

This is head.php line 2:

<head>
    **<title>E-Pressing - <?php echo $titre; ?></title>**
    <link href="css/bootstrap.css" rel="stylesheet">  
    <meta charset="UTF-8">
    <link href="css/business-frontpage.css" rel="stylesheet">
    <link href='http://fonts.googleapis.com/css?family=Poiret+One' rel='stylesheet' type='text/css'>
    <link href='http://fonts.googleapis.com/css?family=Lato:100,300,400,700,900,100italic,300italic,400italic,700italic,900italic' rel='stylesheet' type='text/css'>
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
</head>

Thanks for your help!

score 2 · Answer 1 · answered Feb 26 '14 at 02:18

2

The 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.

<html>
<?php
/* This will give an error. Note the output
* above, which is before the header() call */
header('Location: http://www.example.com/');
exit;
?>

Drink at the fountain: http://php.net/manual/pt_BR/function.header.php
;)

answered Feb 26 '14 at 02:18

Rafael Soufraz

974
3
11
28

Thanks for the answer but i already know that and i have check but i don't find the mistake ! – Alex Moody Feb 26 '14 at 02:26
Try invert the if. `if(!isset($_SESSION['auth']) && $_SESSION['auth'] != true){` so, change the header. I faked here and it works. – Rafael Soufraz Feb 26 '14 at 04:00

score 1 · Answer 2 · answered Feb 26 '14 at 02:16

You cannot have white space before either of the following lines:

session_start();
header('Location:auth_form.php');

You can also "hack fix" this by putting ob_start() at the very start of your PHP script to enable output buffering of your content (only do this if you have no choice)

score 0 · Answer 3 · answered Feb 26 '14 at 02:16

0

That error means you have output somewhere before you call session_start. You need to make sure it is the first thing you call (or as close as you can get it)

answered Feb 26 '14 at 02:16

Machavity

30,841
27
92
100

PHP cannot modify header

3 Answers3