PHP (Hypertext Preprocessor) Info.

Download Php (PHP 4 , PHP 5) session_start -- Initialize session data Descriptionbool session_start ( void )

Hypertext Preprocessor; an open source, side, HTML embedded scripting language used to create dynamic Web pages. It is compatible with many different types of databases and is now in its 5th incarnation.

Developer Php Session_start() creates a session or resumes the current one based on the current session id that's being passed via a request, such as GET, POST, or a cookie.

PHP PHP, or Hypertext Processor, embedded scripting language. Much of its syntax is borrowed from C, specific features thrown in. The goal of the language is to allow web developers to write dynamically generated pages quickly. For rmation, //www.php.

Database Php This function always returns TRUE.

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Php Xml : If you are using cookie-based sessions, you must call session_start() before anything is outputted to the browser.

In the second sentence of the section entitled Functions Checking the Free Store, ctrdbg.h should read crtdbg.h. 00 1 521 Preprocessor symbol The preprocessor symbol _NDEBUG should be _DEBUG. 99 1 535 MFC Hierarchy Diagram Each arrow in the diagram points to a derived class from its base class. 99 1

File Php 1. A session example: page1.php <?php
// page1.php

Sun ONE Web Server 6. php 4.4. [ 52] info ( 382): Using [Zend Sun ONE Enabler, Version 1.0.0] from [Zend Technologies Ltd.] [ 52] failure ( 383): Can not start process for binding '/ php' (80.80) php seems to run fine outside of the web server. in fact, that is the php that was used for the Enabler installation. Help ! thanks, tom

Php Upgrading Session_start();

Php Forum Echo 'Welcome to page #1';

Flash Php $_SESSION['favcolor'] = 'green';
$_SESSION['animal'] = 'cat';
$_SESSION['time'] = time();

Ajax Php // Works if session cookie was accepted
echo '<br /><a href="page2.php">page 2</a>';

Dream Foundation Php Weaver // Or maybe pass along the session id, if needed
echo '<br /><a href="page2.php?' . SID . '">page 2</a>';
?>

Php Proxy After viewing page1.php, the second page page2.php will magically contain the session data. Read the for information on as it, for example, explains what the constant SID is all about.

Nuke Php Theme 2. A session example: page2.php <?php
// page2.php

Php Security Session_start();

Editor Php Echo 'Welcome to page #2<br />';

Hosting Mysql Php Web Echo $_SESSION['favcolor']; // green
echo $_SESSION['animal']; // cat
echo date('Y m d H:i:s', $_SESSION['time']);

4th Development Edition Mysql // You may want to use SID here, like we did in page1.php
echo '<br /><a href="page1.php">page 1</a>';
?>

Php Web If you want to use a named session, you must call session_name() before calling session_start().

Development Mysql Php Web Session_start() will register internal output handler for URL rewriting when trans-sid is enabled. If a user uses ob_gzhandler or like with ob_start(), the order of output handler is important for proper output. For example, user must register ob_gzhandler before session start.

Index Php : Use of is recommended rather than ob_gzhandler()

Download Php : As of PHP 4.3.3, calling session_start() while the session has already been started will result in an error of level E_NOTICE. Also, the second session start will simply be ignored.

Developer Php See also , , and session_id().

Database Php User Contributed Notes
session_start charlie at linuxdsl dot co dot uk
20-May-2004 06:59 The following code is a nice simple way to check for cookie support without needing any intermediary pages to check it has been set.

Php Xml // Set the name of the cookie (nicer than default name)
session_name("SID");

File Php // Set cookie to expire way into the future so it persists
session_set_cookie_params (60*60*24*365*10, '/', '.mydomain.com',0);

Php Upgrading Session_start();
if ( SID != "" ) {
header("Location: /nocookie.php");
exit();
}

Php Forum If you would also like to check for a certain value (e.g. to see if they are logged in) you could use this code instead:

Flash Php Session_name("SID");
session_set_cookie_params (60*60*24*365*10, '/', '.mydomain.com',0);
session_start();
if ( SID != "" ) {
header("Location: /nocookie.php");
exit();
} else {
if (!(isset($_SESSION['uid']))) {
header("Location: /expired.php");
exit();
}
} mzajonc at pomona dot edu
09-May-2004 06:27 The way PHP5 creates session ids has changed. No longer are session ids always 32 characters. Rather it depends on how session.hash_function and and session.hash_bits_per_character are set in php.ini. The default now gives 27 characters. To go back to 32 change the function to 1 and and bits to 5 or function 0 and bits to 4.

Ajax Php This problem is particularily relevant for people using custom session handlers. For example, it affects phpSecureSessions. paul at cantos
13-Jan-2004 04:05 If you need to call session_start() twice - eg if you are manually destroying and recreating a session, it is essential to disable transient SIDs before the second call, and re-enable them afterwards. Otherwise the URL rewriter will get called twice and it is likely (in PHP 4.2.3, at any rate) to trash your HTML output when doing so.

Dream Foundation Php Weaver Eg:

Php Proxy Session_start();
if ( some_expression_if_need_to_rebuild_session }
{
ini_set('session.use_trans_sid', 0);
# ... do whatever you need to do to trash the old session
# ... and set up the new one
session_id($new_sessionid);
session_start();
ini_set('session.use_trans_sid', 1);
}

Nuke Php Theme Presumably session_regenerate_id() doesn't have this limitation, but not everyone has upgraded to a PHP version that includes that function! webhead at web-feats dot com
30-Dec-2003 12:28 PRESERVING STATE WHEN CALLING A GD-GENERATED IMAGE

Php Security How to preserve state when you're doing something like this:

Editor Php File 1:
<img src='quadrant_image.php'>

Hosting Mysql Php Web File 2:
quadrant_image.php

4th Development Edition Mysql Quadrant_image.php is dynamically generated using GD2 library. The problem is, File 1 has already loaded before a GET request is issued for File 2, so it's too late for File 1 to set a cookie.

Php Web <img src='quadrant_image.php?a=$a&b=$b'> would work but what if you want to pass arrays which exceed the 256 character limit for GET?

Development Mysql Php Web File 2 could pass state back to File 1 by putting File 1 in a frameset coupled with an invisible frame, File 2 writing state to a file, and finally File 1 loading the file that was written, something like this:
File 1:
<img src='quadrant_image.php' onLoad='parent.invisFrame.location=\"jsArray.htm\"'>

Index Php Besides being slow, cumbersome and extremely inelegant, this burdens the app with the added complexity of frames.

Download Php Finally, we can't use $_GLOBALS to pass state as File 1 and File 2 have different scopes.

Developer Php The solution is to use $_SESSION:

Database Php File 1:
session_start();
$_SESSION['num_of_matches'] = mysql_num_rows($result);
$_SESSION['quadrant'] = $quadrant;
$_SESSION['coords_array'] = $coords_array;
print("<img src='quadrant_image.php?" . SID . "'>");

Php Xml Here, the first session variable is an int, the second a string, the third an array. An added bonus of using sessions is that php handles all serialization for you automagically.

File Php Then in File 2:
// resume previous session
session_start();
$my_num_of_matches = $_SESSION['num_of_matches'];
$my_quadrant = $_SESSION['quadrant'];
$my_coords_array = $_SESSION['coords_array'];

Php Upgrading Et voila. christopher at cdbsi dot com
24-Dec-2003 05:37 For those of you who want to remove PHPSESSID from all of the links and URL. I have written a solution.

Php Forum If ($_GET[PHPSESSID]) header('Location: '.ereg_replace('[&|\?]PHPSESSID=[^&]+','',$REQUEST_URI)); ma at technoprint dot ch
25-Jun-2003 11:17 I solved the Problem that the session cookie isn't set in IIS5/CGI after redirect with a client side redirect. Not very clean but it works. Like this:

Flash Php <?
session_start();
$_SESSION["foo"] = "bar";
redirectJS( "proceed.php" );

Ajax Php function redirectJS( $uri ){?>
<script type="text/javascript">
<!--
document.location.href="<?php echo $uri ?>";
-->
</script><?
die();
}
?> m dot kuiphuis at hccnet dot nl
24-Jun-2003 09:37 [Editors Note: For more information about this
]

I use name-based virtual hosting on Linux with Apache and PHP 4.3.2.
Every time when I refreshed (by pressing F5 in Internet Explorer) I noticed that I got a new session_id. Simultaneously browsing the same site with Netscape didn't give me that problem. First I thought this was some PHP issue (before I tested it with Netscape), but after searching a lot on the internet I found the problem.
Since I was using name based virtual hosting for my testserver and we have different webshops for different customers I used the syntax webshop_customername.servername.nl as the domain-name.
The _ in the domain name seemed to be the problem. Internet Explorer just denies setting the cookie on the client when there is a special character (like an _ ) in the domain name. For more information regarding this issue:
Stupidly enough, this information was related to asp (yuk :o) gadgetguy03 at lycos dot com
21-Jun-2003 01:18 SESSION LOST ON HEADER REDIRECT (CGI on IIS 5.0)

Dream Foundation Php Weaver I realize there are numerous scattered posts on this issue, but I would like to add my 2?since it took me a whole day and a download of the LiveHTTPHeaders Mozilla plugin to figure it out.

Php Proxy On the **CGI** version of PHP on IIS 5.0/Windows 2000, the following code will not work as expected:

Nuke Php Theme /***** sess1.php *****/
session_start();
$_SESSION["key1"] = "testvalue";
header("Location: sess2.php");

Php Security /***** sess2.php *****/
session_start();
echo "key1 = '".$_SESSION["key1"]."'";

Editor Php PROBLEM:
All session data is lost after a header redirect from the first page on which the session is initialized. The problem is, the PHPSESSID cookie is not being sent to the browser (ANY browser, IE or Mozilla) on the initial session page with the header("Location: ...") redirect. This is unrelated to client cookie settings - the set-cookie: header just isn't sent.

Hosting Mysql Php Web SOLUTION:
I was able to remedy the problem by switching to the ISAPI DLL version. This seems to be an MS/IIS bug, NOT a PHP bug - go figure. I hope this saves you some headaches especially with your user authentication scripts!!

4th Development Edition Mysql The closest matching "bug" report I found:
emmajane at xtrinsic dot com
09-Jun-2003 11:38 I am working on a site where users have to log in before they can play around. The user authentication is done with PHP and sessions. For one of the sections all content editing is done in a pop-up window. For some reason Internet Explorer was behaving as if it were being logged out of the system in the pop-up window--even though the parent window was correctly logged in. i.e. the parent window was fine, but not the new javascript window.

Php Web To overcome this I added the session ID directly to the URL that was opened in the pop-up window:

Development Mysql Php Web <?PHP $thisSession = Session_Name().'='.Session_ID(); ?>

Index Php Onclick="window.open('url.php?<?PHP echo $thisSession;?>', 'win', ''); return false;"

Download Php Of course that's not quite all the parameters that go into the javascript, but hopefully it's enough to help someone else out. :)

Developer Php Thanks to Jason for the code!
gmgiles at pacbell dot net
28-Apr-2003 12:50 Regarding client-side cookies, session_start(), and browser privacy settings: if you use custom login session/validation code for your website, and find that users are unable to login with valid username/password, their browser privacy settings may be to blame - their browser is likely blocking client-side cookie creation.

Database Php Internet Explorer's "Medium-High" privacy level (and higher) can block client-side cookies, and if your session verification code relies on checking a session variable before displaying a page (i.e.: $_SESSION[user_name]), the verification code might not behave as you expect it to.

Php Xml Unfortunately, session_start() always returns TRUE whether the client cookie was created or not, so you'll need to roll your own error checking code. The following is simplified excerpt from the custom verifySession() function I call at the top of each page; this snippet should give you a rough idea for your own error checking...

File Php /* example start */

Php Upgrading Session_start();

Php Forum // check to see if session exists
// assumes $_SESSION[user_name] was previously defined by your custom login validation code
switch (isset($_SESSION[user_name])) {
case TRUE:
// Client cookie was probably created.
echo 'Session verified.';
break;
case FALSE:
// Client cookie either doesn't exist or wasn't created.
// Browser privacy setting may be set too high.
echo 'Verificiation FAILED!';
break;
}

Flash Php /* example end */

Ajax Php I suggest that if you require client-side cookies to allow logins, simply mention that fact immediately above your login prompt. Tailor the above code to your own specific site design. YMMV. benja at benja dot be
15-Apr-2003 05:45 Just for info, session_start() blocks if another PHP using the same session is still running in background. It seems it's waiting the other PHP to finish... and sometimes it can be a problem. Create 2 different sessions by setting 2 different names : session_name() solve the problem.

Dream Foundation Php Weaver Benja. jeroen at unfix dot org
14-Mar-2003 07:24 Ofcourse one can call the session functions from an object
and even stuff a class into the session, it just needs some tricks ;)

Php Proxy Example:

Nuke Php Theme Class Site()
{
var $db_open;
var $error;

Php Security function Site()
{
$this->db_open = false;
$this->error = "No errors";
}

Editor Php function IsOpen()
{
return $this->db_open;
}

Hosting Mysql Php Web function OpenDB()
{
$this->error = "Not implemented";
}
}

4th Development Edition Mysql Function fireup()
{
global $site;
session_start();
if (isset($_SESSION["site"])) $site = &$_SESSION["site"];
else
{
$_SESSION["site"] = new Site();
$site = &$_SESSION["site"];
}

Php Web if (!$site->IsOpen() &&
!$site->OpenDB())
{
echo $site->error;
}
}

Development Mysql Php Web Now call the fireup() function from your main page et tada
$site is your globally retained class in which you can stuff interresting things like database connections. Do remember to
declare them with 'var' in your class base like above. ming
25-Feb-2003 03:32 if you are dealing with forms and session_start() you might experience that all form-values will automatically be emptied after returning to the form with the browser's back-button or javascript's history.back().

Index Php This is especially annoying if you want to enable your users to use the browser's back button to apply corrections to the inputted data on the previous page.

Download Php Add this line right after calling session_start() to solve the problem:

Developer Php Header("Cache-control: private");

Database Php Now, users can hit the back-button to access the form containing all the information they've inputted before. e8boman at etek dot chalmers dot se
27-Jul-2002 05:28 Probably this link () can give you a hint about how to solve your problem. The author describes how to write a custom session handler implementing database support. mickey at UNSPAMwebsoft dot com
20-Mar-2002 12:00 A note on Windows installations with an NTFS file structure:

Php Xml Make sure you give your Internet user account (usually IUSR_MACHINENAME) "Modify" access to the session.save_path directory. Otherwise session_start() will silently - and oh, so slowly - fail.

File Php ("Modify" is a Win2k term, but the concept translates to older IIS installs).

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