Strange modification error of headers

benrich

Right, this is odd. Help would be greatly appreciated.

I'm developing a website (http://174.132.115.253/~mohawks/signup.php) and a signup form. I have the same version of the website A) on my local machine and 😎 on some webspace. The link above is on the webspace.

On the webspace, reguardless what fields i fill in, when the page reloads after pressing submit I get the good old "Warning: Cannot modify header information - headers already sent by (output started at /home/mohawks/public_html/global_app.php:10) in /home/mohawks/public_html/signup.php on line 41" error message. I've made sure all header outputs are before the <HTML> tag and i've removed any stray spaces or returns in my editor.

Line 10 within global_app.php has my doctype

echo '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">';

If I remove this line everything works great!, but of course i need my doctype and regardless where I put it the error persists.

Now, the localhost version of the same form also doesn't work but in a different way.

When the submit button is pressed firefox pauses to think for a second then offers this error message: "The connection was reset. The connection to the server was reset while the page was loading." (same in ie and chrome with less hopeful error msgs). This differs from the webspace version in that when I remove the doctype nothing changes. However I can remove a function call which does remove the error.

include 'include/functions/send_email.php'; <-- this i can edit out and it works fine

<?php
function send_email($f_name='',$l_name='',$to='',$from='',$subject='',$body='')
{
$headers = "MIME-Version: 1.0\r\n";
$headers .= "Content-type: text/html; charset=iso-8859-1\r\n";
$headers .= "To: ".$f_name." ".$l_name." <".$to.">\r\n";
$headers .= "From: ".$from."\r\n";
if(mail($to, $subject, $body, $headers)) {		//sends email (as per settings in php.ini) and returns true if successful
	return true;
}
return false;
}
?>

So there you go.. crazy stuff! I'm pretty sure they are the same error but because the php versions on the localhost (v5.3.0) and webspace (v5.2.9) are different they are being handled in different ways.

Any thoughts anyone? or anymore info you need?

ta!

dagon

move the code around so that the echo is below the headers output.

benrich

I've already gone through my code doing that.

Unless echoing my DOCTYPE comes into that category, but i dont think so(?). DOCTYPE needs to start the beginning of any document yeah?

dagon

ANY output

Remember that 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.

header

benrich

Well, i've moved my DOCTYPE to the line preceding my <html> tag and double checked there are no other outputs before that. Error still persists 🙁

dagon

if the error says there's output, then there is, how about posting your code, and the error.

benrich

I'd be happy to

signup.php is what the browser calls first:
(global_app is lower down)

<?php
include("global_app.php");

//I've omitted irrelevant code here

if(isset($_POST['submit_check'])) { //if user has pressed submit
//I've omitted irrelevant code here - code that puts user inputs into variables+sessions
    [color=green]//I've omitted more code here - code that puts a list of errors into $error[/color]
if(isset($error)) { //if there is an error, reload page. Code elsewhere will pick them up and ask user to try again
header("Location: " . $_SERVER['PHP_SELF'] . "?" . $error);
}

//I've omitted irrelevant code here - composes email into $first_name, $last_name, $email, $from, $subject and $body.

include 'include/functions/send_email.php';
if(send_email($first_name,$last_name,$email,$from,$subject,$body)) { //calls function that sends the email
//echo $confirmation_text;
} else {
//echo 'There was an error sending the email';
}
}
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head><?php include 'head.php'; ?></head>
<body>
<?php include 'header.php'; ?>
<div id="background_main"></div>
<div id="clipboard">
<?php include 'clipboard_top.php'; ?>
<div id="container">
<div id="container_left"></div>
<div id="container_right"></div>
<div id="container_center">
<?php include("pages/template.php"); ?>
</div>
<div id="container_ussu"><img src="images/ussu_frisbee.jpg"></img></div>
</div>
<div id="hand"><img src="images/hand.png"></img></div>
<div id="bottom"></div>
</div>
<div id="footer"><img src="images/feet.png"></img></div>
</body>
</html>

You can see the very first line calls global_app.php which includes my DOCTYPE:

<?php
session_start();
include("include/sys_constants.php");
include("include/functions/db_connect.php");
db_connect($DB_NAME);

$path_parts = pathinfo($_SERVER['PHP_SELF']);
$active_page = $path_parts['filename'];

//I've omitted irrelevant code here
include("pages/content/" . $active_page . ".php");?>

original files also attached

Thanks btw! Far too many hours have been spent on this.

dagon

what's the error message?

benrich

Well, like the first post says, different things happen on different servers (localhost or a webserver)..

On my localhost, firefox pauses then offers: "The connection was reset. The connection to the server was reset while the page was loading."

As for the webspace i've just uploaded all those changes and it appears to be working!..

Right, with the information you've handed me i've taken a look around. localhost php error logs suggest it cannot connect to the SMPT server i've installed, which probably explains firefox's error message.

Moving the DOCTYPE and uploading the changes onto the webspace seems to have cleared the problem there (and because its setup properly with a SMTP server its not erroring at all)

I need to spend some time checking these assumptions

cheers!

benrich

Those assumptions were correct, so all is good. Thanks again!