I tried to add the command <?php session_start(); ?> before the first line of an index.html - file. Aside from that, the file only contains html statements.
When I noticed that the php-code was not getting interpreted, I changed the ending of the file to index.php, which solved that issue.
Now I am wondering whether what I did is an ugly hack or actually an accepted practice? Is it ok to add a php-prefix to a file that is otherwise html?
Also, I am sadly still getting the following error:
session_start() [function.session-start]: Cannot send session cache limiter - headers already sent . In case my above practice is fine, what causes this error?
What you did is what you're meant to do.
Filesystem-based webservers, such as Apache and IIS (for the most part) interpret a requested file based on its file extension and process it accordingly. When a user requests a .html file then the server will return the raw bytes of the file, whereas if the user requested a .php file then it will run it through the PHP module or CGI program which generates the desired output.
You can configure your webserver (assuming you're not on a shared hosting service) to always process .html files with PHP, but it's better to hide implementation details in your URIs and use URL Rewriting instead (something Apache and IIS7+ have full support for).
With respect to the session_start() error you're getting - that's because session_start has to be called before anything is output to the client, which means that the <?php session_start() ?> part has to be at the very start of your document with no plaintext or blank-lines before it. You can have some PHP code before the call, but be sure that the PHP code is not sending any responses or headers.
Keep in mind that .php Files should parse through both PHP & HTML Tags. Placing a tag at the begining of the document is a common practice.
Also like #markus-tharkun mentioned - it really depends on what you are trying to do with the PHP code. If you just wanted to put a Timestamp in a Header of your HTML Doc it could be as simple as the following:
<h2>
<?php echo date('l jS \of F Y h:i:s A'); //Prints Date inside the H2 Tag ?>
</h2>
Once again, i could put this code anywhere inside my Tag and it would print out the current date using PHP. PHP can play interesting tricks with scope therefore it should always be paid close attention to.
Related
I am having this error in PHP:
session_start(): Cannot send session cache limiter - headers already
sent
I know I have to put session_start() even before the html <head>, what I am doing. The issue here is that I am using id containers for ajax generated content.
For example, I have a button in the homepage.php which updates some calculate.php file in a divResults, and this calculate.php begins with session_start(). However, this warning is appearing inside divResults.
How could I solve it. Is it possible to simply ignore the warning. How?
(I don't have this problem in XAMPP, only using an external hosting provider)
Thanks
Based on your problem following errors may possible.
you write session_start(); in somewhere middle or end of the .php file so you need to put session_start();at top of .php file just after <?php.
May be some empty lines are there in your .php file at the beginning or end, because of that also this error will arise. remove those empty line.
I have this code inside of my header
<?php
define('RELPATH','http://www.saint57records.com/');
include_once(RELPATH.'sidebar.php');
?>
and an example line of code in the sidebar
<img style="margin:10px;" src="<?php print RELPATH;?>images/logo.png" width="60px"/>
but when it gets to the page it includes the file correctly but all the links inside of the file just print RELPATH instead of the web url like this
<img style="margin:10px;" src="RELPATHimages/logo.png" width="60px"/>
It works fine on the other pages of my website, just not inside of Wordpress. Does anyone know what might be causing this issue?
The short answer is to provide a filesystem path to RELPATH, not a web URL.
The long answer is that when you use a web URL to include a PHP file, the PHP file will be treated like an external source. It will be called remotely, executed in a process of its own, and return the results. A constant defined previously can not have an effect in this remote resource.
If http://www.saint57records.com/ is on a different server, you'll have to pass RELPATH to it some other way, e.g. through a GET variable (which you'd have to sanitize with htmlentities() prior to use.) However, including content from a remote server in this way isn't good practice. It'll slow down your page as it'll make an expensive web request. If the target server is down, your page will time out.
I've read so many different inputs on this, so I figured I would ask on here.
Is there anything wrong or dangerous about using full links inside a php include?
Examples,
<?php include('http://www.domain.com/blah.php'); ?>
<?php
define('WEB_ROOT', './'); // relative path to /
include('layout.php');
?>
compared to using
<?php
include('../blah.php');
?>
include('http://www.domain.com/blah.php') goes out and makes an actual HTTP request to the web server, returning the contents of the URL after the web server has processed them, just as you'd see when entering that URL in your browser.
include('../blah.php') includes the local file from disk one directory higher.
The two are completely different things and you do not want to include a URL when you mean to include a local file. Even if the two are supposedly the same file, PHP cannot know that. Accessing a URL and accessing a local file path are entirely different things. It's not possible to infer that the two are the same.
<?php include('http://www.domain.com/blah.php'); ?> is very dangerous, you can't know in 100% what is the code you will get!!! becuse PHP do HTTP request and someome can do ManInTheMiddel attack and to change the code you will get, and to hack your site.
I am currently working on a game in PHP and jQuery and at some point I will need to use the .load() from jQuery to load a PHP page into a div. That page will load some player information based on their login information, account id, etcetera, stored into an array inside $_SESSION["arrayname"].
It works perfectly on all sites, except those where jQuery load() is use. On easyphp, I got no errors, but on my web host server im getting this:
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /fr/game/map.php:1) in fr/game/map.php on line 6
Here is my code:
<?php
require_once("../../connectionRO.inc.php");
//used to check if we see the array in session, and i dont when i load it with jquery
if(!ISSET($_SESSION["comptejeu"]))
{
require_once('../../classInfoCompte.php');
session_start();
require_once('../../lg.php');
require_once("./glg.php");
}
$ic = new infoCompte;
$ic = $_SESSION["comptejeu"];
?>
I understand that at this point a lot of stuff is already output to the page before that is loaded. Could anyone point me to a better way to retrieve the information that I need from that array to build my object from my class?
Thank you.
Since you are getting this error as output started at /fr/game/map.php:1 (note: line 1) I will place money on you having whitespace or a BOM before the opening <?php tag in /fr/game/map.php.
Make sure the opening < is the first character in the file. If you file is UTF-8, make sure it is UTF-8 without BOM, or convert it to ASCII.
Wrong:
<?php
Right:
<?php
Either there is some white space in your PHP file, there is some whitespace in classInfoCompute.php or there is a function/method call that triggers output in either this or the classInfoCompute file. Sessions depend on cookies, and cookies depend on HTTP headers. Once content has been output, the headers are already sent and you can't send a new one.
There are plenty of questions and answers on Stack Overflow that cover this issue, but it boils down to either sweeping the problem under the carpet (with output buffering), or fixing it properly (by finding what's causing content to be output before your call to session_start and either removing it or moving it to later in the script, or moving session_start to earlier in the script).
If your script mixes HTML and PHP then make sure that the session_start occurs before the first bit of HTML. Otherwise, you'll have to hunt around for white space. If the file is saved as UTF-8 then your text editor might have attached an unnecessary Byte Order Mark (BOM) to the start of the file. Make sure that your file is being saved without a BOM, because it will be treated as content and trigger output to the client (and put a weird character at the start of the output).
I have the following:
$imageurl = "<img class='item_thumb'
src='getimagethumbnail.php?imagename=".urlencode($product_image)."&from=".$prodimagedir."'
min-width='150' min-height='150' border='0' class='item_thumb'>";
Which creates the following html:
<img class="item_thumb" border="0" min-height="150" min-width="150"
src="getimagethumbnail.php?imagename=productsmall_1248886833bloggingbok.jpg&
from=products/"/>
However, the image does not show up. I point my browser to that src link and it gives me a bunch of unreadable text which I am assuming is the image meaning that the script getimagethumbnail is working fine. (I am guessing).
But as I said, the image is not appearing at all. What is wrong and what steps can I take to determine the problem?
Just to add, when I point my browser to that src link: It also gives me:
Warning: Cannot modify header information - headers already sent by
(output started at /home/dji/public_html/getimagethumbnail.php:35) in
/home/dji/public_html/includes/functions.php on line 4953
I am assume this is because of the output?? This script was working fine and I have made no changes to it as far as I am aware!
Thanks
You are trying to send the header('Content-Type') command, after outputting whitespace/characters.
You need to make sure that the header command is before anything is printed on the page.
This will work:
header('Content-Type: ....');
readfile('file.png');
This won't
readfile('file.png');
header('Content-Type: ....');
This is because the header command tells the browser what to look for in the content. All of the headers must be sent before any content because that is how the connections works. The browser can't be told what to expect after the content has already been sent.
Open Connection With Server -> Get Headers -> Get Content -> Close Connection
One of the big reasons behind this is encoding. As the content comes through, the browser has to decode it properly. If you send a header in the middle of the page telling the browser that the encoding type is a, when it was processing it like b, things can get really confusing.
So, in order to send the headers properly, you must put the header command before any output.
That error is caused when you print stuff to the output and then attempt to use the header() method. You shouldn't be outputting anything until after you do what you need with header(). Nothing should precede this, not even white-space.
You already have produced some output (on line 35) before setting the header for the image type. This might simply be a whitespace between php tags, or something you forgot to remove.
Your getimagethumbnail.php script is not generating a valid image; it's including text in it (the warning message you quote), which prevents browsers from rendering it. Judging by the error text, I'd guess this is due to changes made either to getimagethumbnail.php or functions.php.
Fundamentally, the problem is that functions.php is attempting to call header() after output has already been sent to the browser, which just plain won't work. You need to check both files and make sure that any calls to header() come before anything else that sends data to the browser.
You may want to turn off the display_errors setting, as any code which generates any warning or error for any reason will cause the problem you're seeing if the warning/error occurs before your header() calls. (Just make sure you have error logging on, so you can still see what's going wrong!)