"Cannot modify headers information" error

Mad_Max2

Having thought I'd got this issue fixed and the code working nicely, I'm getting this error:

Warning: Cannot modify header information - headers already sent ... on line 43

My code is as follows (needless to say I can't see the problem, but I'm sure it's an obvious solution that I'm missing):

<?php

/* Subject and e-mail variables */

$emailSubject = 'Request a Call';
$webMaster = 'enquiries@mydomain.co.uk';
$formSuccess = "http://www.mydomain.co.uk/form-success.html";
$formError = "http://www.mydomain.co.uk/form-error.html";

/* Gathering data variables */

$titleField = $_POST['title'];
$firstnameField = $_POST['first_name'];
$surnameField = $_POST['surname'];
$daytimetelField = $_POST['daytime_tel'];
$eveningtelField = $_POST['evening_tel'];
$marketingsourceField = $_POST['marketing_source'];
$termsandconditionsField = $_POST['terms_and_conditions'];

/* Anti-Spam */

if ( preg_match( "/[\r\n]/", $firstnameField ) || preg_match( "/[\r\n]/", $surnameField ) ) {
	header( "Location: $formError" );
	exit ;
}

/* Message to WebMaster */

$body = <<<EOD
<br><hr><br>
<b>Full Name:</b> <br>$titleField $firstnameField $surnameField <br><br>
<b>Daytime Telephone:</b> <br>$daytimetelField <br><br>
<b>Evening Telephone:</b> <br>$eveningtelField <br><br>
<b>How did you hear about us?</b> <br>$marketingsourceField <br><br>
<b>Accepts T&Cs:</b> <br>$termsandconditionsField <br><br>
EOD;

$headers = "Content-type: text/html\r\n";
$success = mail($webMaster, $emailSubject, $body, $headers);

/* Successful Submission Redirect */

header( "Location: $formSuccess" );
exit ;

?>

Any help would be most gratefully received.

Many thanks,

Max

bradgrafelman

You've cut off the second most important part of the error message. PHP will tell you exactly where output began.

Also, when posting PHP code, please use the board's [noparse]

..

[/noparse] bbcode tags as they make your code much easier to read and analyze.

Mad_Max2

Ah sorry, here's a fuller version of the error:

Warning: Cannot modify header information - headers already sent by (output started at /websites/123reg/LinuxPackage22/[...]mysiteurl.co.uk/public_html/formprocess_request-a-call.php:1) in /websites/123reg/LinuxPackage22/[...]mysiteurl.co.uk/public_html/formprocess_request-a-call.php on line 43

Does that provide the information required?

Thanks for your help.

Max

laserlight

Looking at "formprocess_request-a-call.php:1", I would guess that you have a blank line at the top that shouldn't be there.

Mad_Max2

laserlight;11027807 wrote:
Looking at "formprocess_request-a-call.php:1", I would guess that you have a blank line at the top that shouldn't be there.

As per the PHP coding, sadly it's not that simple. There's no space, line or anything there. :bemused:

laserlight

Ahh... check that you don't have a Unicode byte order mark (BOM) there. This can be done with certain editors, or by using a hex editor or hex dump.

Mad_Max2

Hi laserlight,

Thanks for your reply.

Unfortunately I must confess I'm a beginner to PHP and don't quite understand what you're suggesting or how to check. Would you be able to provide any further details for me please?

Best wishes,

Max

Mad_Max2

Update: I managed to find a few articles on BOMs and how to detect them. I've saved the files without the BOMs and so far so good! I'll let you know if I have any further problems, but thanks so much - I'd never have found the solution without you!

Max

sneakyimp

OK that sounds like it was fairly tricky (and props to laserlight and Mad Max for working it out). Max, can you tell us what editor you were using? Also, I find it curious that PHP wouldn't know how to distinguish a BOM from actual PHP code and/or output.

Weedpacket

Also, I find it curious that PHP wouldn't know how to distinguish a BOM from actual PHP code and/or output.

There's no way it could: just because a file starts with [font=monospace]\xEF\xBB\xBF[/font] doesn't mean it's a UTF-8-encoded text file (which - in a sensible world - would be a sign that it had been converted from UCS16-LE or UCS16-BE which use the Byte Order Mark to distinguish themselves from each other). Some brain-dead editors use [font=monospace]\xEF\xBB\xBF[/font] to say "hey, this is UTF-8 encoded!" but that's not what it's for.

sneakyimp

Weedpacket;11027925 wrote:
There's no way it could

Welllllll....not saying this is how things should be (and they probably shouldn't be), but it would seem that certain text editors seem to avoid putting those bytes at the beginning of one's edit window when encountering a BOM at the beginning of a text file and additionally make the assumption that the bytes that follow represent UTF-8 text (or something). While it is entirely possible that someone might make a poorly designed PHP file that starts with these bytes:

\xEF\xBB\xBF are the bytes that represent a BOM which in some cases...
<?php
/**
 * some-fing-template.php
 */
?>

the odds of this happening seem fairly remote. I find it difficult to imagine any other circumstances under which a PHP file would start with a BOM. I expect I'm headed for some more mind-hurting realizations thanks to Weedpacket's generous donation of know-how here.

It seems odd to me that there aren't distinct file suffixes for UTF8 text files and ISO text files and LATIN-1 text files and so on. On the other hand, from a PHP perspective, I seem to recall that the entirety of PHP's syntax is expressed in ASCII characters and therefor any byte sequences intended as UTF-8 which happen to live in a PHP file would either have to be a) output living outside the <?php ?> tags or b) somewhere in a quoted string in which case PHP would treat them as precisely the bytes that they are without any care in the world as to that they represent.

Mad_Max2

sneakyimp;11027903 wrote:
Max, can you tell us what editor you were using?

I usually use Dreamweaver, but due to the wonders of 123-reg, I had recently resorted to using Notepad... which was where it all went wrong. With Dreamweaver, when you Save As, it offers a handy little tick box to say if you want BOMs included or not - that's how I fixed it.

Weedpacket

sneakyimp wrote:
I seem to recall that the entirety of PHP's syntax is expressed in ASCII characters and therefor any byte sequences intended as UTF-8 which happen to live in a PHP file would either have to be a) output living outside the <?php ?> tags or b) somewhere in a quoted string in which case PHP would treat them as precisely the bytes that they are without any care in the world as to that they represent.

Nope; you can have non-ASCII characters in identifiers (you can have a variable called [font=monospace]$résumé[/font]).

a) output living outside the <?php ?> tags

Which is exactly where the BOM - when it's present - is found.

Bonesnap

Mad Max;11027937 wrote:
I usually use Dreamweaver, but due to the wonders of 123-reg, I had recently resorted to using Notepad... which was where it all went wrong. With Dreamweaver, when you Save As, it offers a handy little tick box to say if you want BOMs included or not - that's how I fixed it.

Oh man, Notepad...

Try out Komodo Edit. The best editor I've ever used. I've converted my entire office and we were a mixture of Dreamweaver, Eclipse, Notepad2, and Notepad++. No one can imagine going back.