PHP: session_register

Description

bool session_register ( mixed name [, mixed ...] )

session_register() accepts a variable number of arguments, any of which can be either a string holding the name of a variable or an array consisting of variable names or other arrays. For each name, session_register() registers the global variable with that name in the current session.

Caution

If you want your script to work regardless of register_globals, you need to instead use the $_SESSION array as $_SESSION entries are automatically registered. If your script uses session_register(), it will not work in environments where the PHP directive register_globals is disabled.

register_globals: important note: Since PHP 4.2.0, the default value for the PHP directive register_globals is off. The PHP community encourages all to not rely on this directive but instead use other means, such as the superglobals.

Caution

This registers a global variable. If you want to register a session variable from within a function, you need to make sure to make it global using the global keyword or the $GLOBALS[] array, or use the special session arrays as noted below.

Caution

If you are using $_SESSION (or $HTTP_SESSION_VARS), do not use session_register(), session_is_registered(), and session_unregister().

This function returns TRUE when all of the variables are successfully registered with the session.

If session_start() was not called before this function is called, an implicit call to session_start() with no parameters will be made. $_SESSION does not mimic this behavior and requires session_start() before use.

You can also create a session variable by simply setting the appropriate member of the $_SESSION or $HTTP_SESSION_VARS (PHP < 4.1.0) array.


<?php

// Use of session_register() is deprecated

$barney = "A big purple dinosaur.";

session_register("barney");



// Use of $_SESSION is preferred, as of PHP 4.1.0

$_SESSION["zim"] = "An invader from another planet.";



// The old way was to use $HTTP_SESSION_VARS

$HTTP_SESSION_VARS["spongebob"] = "He's got square pants.";

?>

Note: It is currently impossible to register resource variables in a session. For example, you cannot create a connection to a database and store the connection id as a session variable and expect the connection to still be valid the next time the session is restored. PHP functions that return a resource are identified by having a return type of resource in their function definition. A list of functions that return resources are available in the resource types appendix.
If $_SESSION (or $HTTP_SESSION_VARS for PHP 4.0.6 or less) is used, assign values to $_SESSION. For example: $_SESSION['var'] = 'ABC';

User Contributed Notes
session_register

T
12-Apr-2005 08:24


make sure you include files as "filename.php" and not "http://www.yourdomain.com/filename.php" or sessions won't work - spent a day trying to figure out this problem.



Also make sure that $_SESSION['$name'] does not any  $name variables that you send with POST OF GET - spent another day until i noticed this could be the cause of my problems.

mantas at systemnetwork dot net
19-Mar-2005 05:40


I have 3 files:



- The first is the form that contains various fields.

- Second is the php script that the form submits data to.  This file then stores acquired values to the session.

- Finally the third file is the php script that accesses data from the session



So the first script:



<?



session_start();



$title = $_POST["title"];

$fname = $_POST["fname"];



$_SESSION["first"] = $fname;



?>



... All we do here is set values from HTTP POST request.



Now the second script:



<?



session_start();



echo $_SESSION["first"];



?>



... Here we try to print out the session variable that was set in the previous script.



This demonstrates the use of $_SESSION.  There is no need to declare $_SESSION to be global since it is already global, thus can be accessed from anywhere.



Tested on PHP 4.

erik«at»phpcastle«dot»com
22-Feb-2005 01:38


Heya....



A way to check out the visitor has cookies enabled or a firewall or virusscanner blocks them...



[file = cookie_check.php]

<?php

  session_start ();

  //Check GET request

  if (isset ($_GET['cookie_check'])){

    //Check session

    if (isset ($_SESSION['session_set'])){

      //Display working message

      echo "working...";

      exit;

      //Or redirect

      //header ("Location: cookie_working.php");

    } else {

      //Display failure message

      echo "failure...";

      exit;

      //Or redirect

      //header ("Location: cookie_fail.php");

    }

  }

  session_register ("session_set");

  $_SESSION['session_set'] = true;

  header ("Location: cookie_check.php?cookie_check=1");

?>



Hope this is usefull for someone :)

matt at atomboost dot com
01-Feb-2005 02:52


Put this in a functions file to check if a user is logged in simply by typing "session_check();"



function session_check() {

    if(!session_is_registered('username')) {

        // redirect to login page

        exit();

    }

}

Hayley Watson
25-Dec-2004 05:12


The posts of Tümmel and Foliot both make the same mistake about storing arrays in sessions when they use "$_SESSION['titel[$i]']". If the intention is to store an array in $_SESSION (or any other array for that matter), the appropriate syntax is $_SESSION['titel'][$i].

Foliot Gerald
07-Dec-2004 09:59


Note on "Tümmel  atop at bluewin dot ch"

>However, when I call the $_SESSION-variable, it is necessary to >use the same counter variable name.

 

> This will not work:

> $p=3;

> echo '<input type =text value ='.$_SESSION['titel[$p]'].'>';

 

> That one is ok:

> $i=3;

> echo '<input type =text value ='.$_SESSION['titel[$i]'].'>';

 

The reason is that PHP register variable in the form

titel[$i]' in the session file

and not in the forme titel[1] in the session file

mikej
21-Nov-2004 03:40


I've noticed that if you try to assign a value to a session variable with a numeric name, the variable will not exist in future sessions.

For example, if you do something like:

session_start();

$_SESSION['14'] = "blah";

print_r($_SESSION);



It'll display:

Array ( [14] => "blah" )



But if on another page (with same session) you try

session_start();

print_r($_SESSION);



$_SESSION[14] will no longer exist.



Maybe everyone else already knows this, but I didn't realize it until messing around with a broken script for quite a while.

baldanders
12-Nov-2004 01:05


If you are using sessions and use session_register()  to register objects, these objects are serialized automatically at the end of each PHP page, and are unserialized automatically on each of the following pages. This basically means that these objects can show up on any of your pages once they become part of your session.

Andrew Hoyt
26-Oct-2004 09:20


Yeah, I had an old PHP book that did things the old way, that was a headache.  I found out that if one took the session variable:



session_start();

//do some type of login

login($username,$password);



$_SESSION["username"] = 1;



and made sure it was set equal to some value, you can check it on your pages with:



if($_SESSION["username"] != 1) {

  print "you need to login";

  //maybe some kind of site redirect here

  exit;

}

//Page content goes here

Hoops, my mistake Tümmel atop at bluewin dot ch
24-Aug-2004 03:24


so sorry, it worked only one time and I still don't know why.(rotlf*):

<? ... while($f=mysql_fetch_row($result))

{$i++;

$_SESSION['foo1['.$i.']'] =$f[0];

$_SESSION['foo2('.$i.')']= $f[1];} ...?>

<? $s=2;

echo '<input type =text value ='.$_SESSION['foo1('.$s.')']>';

?>

Array as usual. Hope it will help.

Tümmel atop at bluewin dot ch
24-Aug-2004 02:41


If you use a lot of $_SESSION variables, you can put them into an array. For example like that:



while($f=mysql_fetch_row($result))

{$i++;

$_SESSION['foo1[$i]'] =$f[0];

$_SESSION['foo2[$i]']= $f[1];

}



However, when I call the $_SESSION-variable, it is necessary to use the same counter variable name.



This will not work:

$p=3;

echo '<input type =text value ='.$_SESSION['titel[$p]'].'>';



That one is ok:

$i=3;

echo '<input type =text value ='.$_SESSION['titel[$i]'].'>';



Hope it will help.

05-Feb-2004 12:19


Here is a dummy example of user logging using only session_register and session_is_registered functions



<************ login_page.php **********>



//put everything you need here to get user information

//html form etc..



<?php

session_start(); 



//we suppose that everything is ok 



$user_is_logged = 1;

if(session_register('user_is_logged') == FALSE) {

    die("cannot register variable !");

}

?>



<A href="i_am_in.php?<? echo SID?>">Press me</A>



<************************************>

<************i_am_in.php**********>

<?php



session_start(); 



if(session_is_registered('user_is_logged') == FALSE) {

  echo "you are not registered !<br>";

} else {

  if ($user_is_logged == 0) {

    echo "you are registered but not valid<br>";

  } else {

    echo "you are registered and valid<br>";

  }

  

}



//if you to terminate session the here

session_unset();

session_destroy();



?>



<************************************>

dominik-ruess at gmx dot de
13-Dec-2003 04:58


Do not even think of using "global" together with "$_SESSION":



<?php



// Will only work on some servers (or some PHP-Versions - I don't know):

function test()

{

      global $_SESSION;



      $_SESSION["test"]=1;

}



// correct way:

function test()

{

      $_SESSION["test"]=1;

}

?>



took me hours to recognize :/

gianni_t76 at yahoo dot it
05-Aug-2003 02:42


You don't need to serialize an object before adding it to a session var



example:



include("class.exmaple.php");

$obj = new exampel ();

$_SESSION['obj']=$obj;



and to resume the object:



include("class.example.php");

$obj = $_SESSION['obj']);

ice at thesurf dot no-ip dot com
02-Apr-2003 06:09


If you use objects it is alsways a good idear to make a var or array that hold your object-handler



exampel:

include("class.exmaple.php");

$obj = new exampel ();



$se_obj = serialize($obj);



$_SESSION['se_obj']=$se_obj;



when you then got on the next page and so a start_session()

and you don't habe includet the classdescription, your object will still not break. 

Just do a 

include("class.example.php");

$obj = unserialze($_SESSION['se_obj']);



and all is fine.

This is a preaty good trick if you do some includings in the next page an use the object in a file you include :)