Problem using php header() function

**fguy64** · 05-17-2009 12:26 AM

Hi this is day1 of my php education, and I'm running into problems early. I'm trying a simple redirect based on correct entry of a password. I checked a few sources and my code seems ok, but...

first my html form...

Code:

<form action="success.php" method="post">
Password: <input type="password" name="password"> <input type="submit" />
</form>

and here is my success.php

Code:

<?php

$pwd = $_POST["password"];

if( $pwd == "123" ) {
	header( "Location: success.htm" );
} else {
	echo "nyeh";
}

?>

when I enter the correct password, I get...

Warning: Cannot modify header information - headers already sent by (output started at /.../.../success.php:

in /.../.../.../success.php on line 13

**gomarc** · 05-17-2009 12:52 AM

The problem may be with success.htm. Your code as posted works fine.

If success.htm =

HTML Code:

<html>
  <body>
  SUCCESS!  
  </body>
</html>

... it will work.

**fguy64** · 05-17-2009 01:34 AM

nah, I double checked and tried again, same problem. The only thing I can think of is the first time I executed the script, I had forgotton to upload my success.htm, but it's there now.

When I checked the php reference for this error, it made reference to some kind of flush() command, but it didn't look like something a newbie had access to, and I didn't try it.

you can find the error here

http://ca.php.net/manual/en/function.flush.php

I wasn't sure if I should try it without a second opinion, maybe it affects the servers?

edit: I should mention that my php file starts an ends with the usual html tags, but I don't think that should be a problem, here is teh entire file

Code:

<html>
<head>
<title></title>
</head>

<body>

<?php

$pwd = $_POST["password"];

if( $pwd == "123" ) {
	header( "Location: success.htm" );
} else {
	echo "nyeh";
}

?>

</body>
</html>

Edit:
ok, I took all the html tags out of my php file and it worked. hmm I thought you could embed php within html tags, but maybe I misread. It's getting late...

**gomarc** · 05-17-2009 01:50 AM

Yes, it does make a difference! You can embed php within html tags, but the header() statement must go before any output, in this case <head><title></title></head>.

**fguy64** · 05-17-2009 02:03 AM

Originally Posted by gomarc

Yes, it does make a difference! You can embed php within html tags, but the header() statement must go before any output, in this case <head><title></title></head>.

I'm not sure I get what you are saying. the tags you mention constitute output? So I tried as below and the problem returned. I made sure there was no white space before or after my php tags.

<html>
<body>
<?php

$pwd = $_POST["password"];

if( $pwd == "123" ) {
header( "Location: success.htm" );
} else {
echo "nyeh";
}

?>
</body>
</html>

**~~Livewire~~** · 05-17-2009 02:12 AM

Originally Posted by fguy64

I'm not sure I get what you are saying. the tags you mention constitute output? So I tried as below and the problem returned. I made sure there was no white space before or after my php tags.

<html>
<body>
<?php

$pwd = $_POST["password"];

if( $pwd == "123" ) {
header( "Location: success.htm" );
} else {
echo "nyeh";
}

?>
</body>
</html>

As soon as any text (even a blank space) is returned, PHP must send headers that indicate a standard HTML webpage.

So, in short, to use header, the very first characters in your document MUST be <?php - this particular string isn't sent to the user, and it just sets it up to process data; unless you echo/print anything to the screen (or a function throws an error and echo/prints it), you can use header to send different headers other than a standard webpage

**fguy64** · 05-17-2009 02:32 AM

ok, so php with header() function is like an exception to the rule.

thanks to both for the help.

**xav0989** · 05-17-2009 11:06 AM

Since you are just starting, this can help you point out that the best practice in coding is to separate code from layout/content. Have a code file that sends headers, then load content, then display it.

**fguy64** · 05-17-2009 11:27 AM

Originally Posted by xav0989

Since you are just starting, this can help you point out that the best practice in coding is to separate code from layout/content. Have a code file that sends headers, then load content, then display it.

yeah, now that you mention it, I do recall reading something like that somewhere. Makes sense and duly noted, thanks.

**xav0989** · 05-17-2009 11:33 AM

that's all the MVC (Model->content, View->layout, Controller->code) thing that developers are praising

Thread: Problem using php header() function

LinkBack

Thread Tools

Display

Problem using php header() function

Re: Problem using php header() function

Re: Problem using php header() function

Re: Problem using php header() function

Re: Problem using php header() function

Re: Problem using php header() function

Re: Problem using php header() function

Re: Problem using php header() function

Re: Problem using php header() function

Re: Problem using php header() function

Similar Threads

Uploading attachments for phpBB3 - Passthru php function disabled?

IPB Installation Page blank - php version problem?

PHP Problem/Ad Problem

Como colocar ads en header de php nuke??

Posting Permissions