Cannot modify header information - headers already sent by

Question

I read a topic about this header but could not make it work for my program. I removed html and space before, but still cannot see what is wrong. the connect.php file purpose is to connect to a database and I use app_config.php file to call handle_error function from connect.php to print any error occurring while attempting to connect to database. Great thanks for your help!

Error is:

Warning: Cannot modify header information - headers already sent by (output started at /home3/alfredbiz/public_html/phpMM/ch05/scripts/connect.php:1) in /home3/alfredbiz/public_html/phpMM/ch05/app_config.php on line 12

here is connect.php

<?php
//appel le fichier de mot de passe
require_once '/home3/alfredbiz/public_html/phpMM/ch05/app_config.php';
require_once '/home3/alfredbiz/public_html/phpMM/ch05/app_connexion.php';

//database connexion
$link = mysqli_connect(DATABASE_HOST, DATABASE_USERNAME, DATABASE_PASSWORD, DATABASE_NAME);

// check connection
if (!$link) {   
$user_error_message = "there was a problem connecting to the database that holds the information we need to get you connected.";
$system_error_message = mysqli_connect_error();
handle_error($user_error_message, $system_error_message);
}

//editer les tables avec controle d erreur
$result = mysqli_query($link, "show tables");
if(!$result){
    die("<p>Error in Listing tables: " .mysql_error() . "</p>");
}
echo "<p> requette executee avec success</p>";
?>

app_config.php

<?php
//set up debug mode
define("DEBUG_MODE", true);

function debug_print($message) {
if(DEBUG_MODE) {
echo $message;
  }
}

function handle_error($user_error_message, $system_error_message) {
header("location: /home3/alfredbiz/public_html/phpMM/ch05/scripts/show_error.php?" ."error_message={$user_error_message}&" ."system_error_message= {$system_error_message}");
exit();
}
?>

Look at your output. There may be a line before that error message. — aynber, Nov 11 '16 at 14:17

score 0 · Answer 1 · answered Nov 11 '16 at 14:21

0

It's likely the echo in the app_config.php file that's causing the issue. Once you echo anything out, you can't change the header information. You would want to move the echo to happen after the header() in the handle_error function.

answered Nov 11 '16 at 14:21

raphael75

2,982
4
29
44

I removed the echo in app_config but no change – Alfred Nov 11 '16 at 14:28

score 0 · Accepted Answer · edited May 23 '17 at 12:13

0

This is a common error caused by BOM (Byte Order Mark). The indicator for this is the fact that the output started on line 1.

See the duplicate thread How to fix "Headers already sent" error for the resolution.

edited May 23 '17 at 12:13

Community

1
1

answered Nov 11 '16 at 14:28

ChristianF

2,068
9
14

as soon as I convert it to UTF-8 with notepad++ I have this error Warning: Cannot modify header information - headers already sent by (output started at /home3/alfredbiz/public_html/phpMM/ch05/scripts/connect.php:7) in /home3/alfredbiz/public_html/phpMM/ch05/app_config.php on line 12 – Alfred Nov 11 '16 at 14:37
still i cannot see any space or html at line 7 – Alfred Nov 11 '16 at 14:39
Please read up on the Byte Order Mark. – ChristianF Nov 11 '16 at 14:42
You was right I used Hes editor Neo to fix this issue it is working – Alfred Nov 11 '16 at 17:10
@Alfred: Good to know, and glad I could help. :) – ChristianF Nov 14 '16 at 07:19

Cannot modify header information - headers already sent by

2 Answers2