session_register

(PHP 4, PHP 5 < 5.4.0)

session_register現在のセッションに1つ以上の変数を登録する

説明

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

session_register() の引数の数は可変であり、 各引数は変数名を保持する文字列または変数名からなる配列 とすることが可能です。 各変数名が処理される毎に、session_register() は、その変数名のグローバル変数を現在のセッションに登録します。

配列 $_SESSION の適当なメンバに設定をするだけでもセッション変数を作成することが可能です。

<?php
// session_register() の使用は推奨されません。
$barney "A big purple dinosaur.";
session_register("barney");

// $_SESSIONの使用が推奨されます。
$_SESSION["zim"] = "An invader from another planet.";
?>

この関数をコールする前に session_start() をコールしていない場合、暗黙のうちに引数を付けずに session_start() がコールされます。 $_SESSION を使う場合はこの動作とは違い、 使用前に必ず session_start() をコールする必要があります。

警告

この関数は PHP 5.3.0 で 非推奨となり、 PHP 5.4.0 で削除されました。

パラメータ

name

変数名を含む文字列、 あるいは変数名や配列を含む配列。

...

返り値

成功した場合に TRUE を、失敗した場合に FALSE を返します。

注意

警告

register_globals を考慮することなくスクリプトを書きたい場合には、 $_SESSION 配列を代わりに使用する必要があります。 $_SESSION のエントリは自動的に登録されます。 スクリプトで session_register() を使用している場合には、それは register_globals を不可としている環境下では動作しません。

注意: register_globals: 重要な注意

PHP 4.2.0 以降、PHP ディレクティブ register_globals のデフォルト値は off となっています。 PHP コミュニティは、ユーザーがこのディレクティブの設定に依存せず、 superglobals のような他の手段を使用することを推奨します。

警告

この関数は、global変数を登録します。 セッション変数を関数の内部で登録したい場合、 global キーワードあるいは $GLOBALS[] 配列を用いてその変数をグローバルとするか、下記のように session 配列を使用してください。

警告

$_SESSION を使用する場合は session_register()session_is_registered() および session_unregister() を使用しないでください。

注意:

セッションにリソース変数を登録することは現在できません。例えば、 データベースへの接続を生成し、接続IDをセッション変数として登録し、 セッションが回復された時点で、接続が有効であることを期待することはできません。 リソースを返すPHP関数は、その関数定義に resource型の返り値を有することが示されている。 リソースを返す関数のリストは、付録 リソース型の一覧 で見ることができます。

$_SESSION を使用する場合は、値を $_SESSION に代入します。 たとえば $_SESSION['var'] = 'ABC'; などのようにします。

参考

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User Contributed Notes 15 notes

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16
Ezion oudpapierdoos at gmail dot com
7 years ago
Below is a fix that may be included in older code to make it work with PHP6.
When needed it recreates the functions
- session_register()
- session_is_registered()
- session_unregister()

The functions inside the function fix_session_register() are only available  after fix_session_register() has run.
Therefore in PHP<6 where there already is a session_register() nothing happens.

<?php
// Fix for removed Session functions
function fix_session_register(){
    function
session_register(){
       
$args = func_get_args();
        foreach (
$args as $key){
           
$_SESSION[$key]=$GLOBALS[$key];
        }
    }
    function
session_is_registered($key){
        return isset(
$_SESSION[$key]);
    }
    function
session_unregister($key){
        unset(
$_SESSION[$key]);
    }
}
if (!
function_exists('session_register')) fix_session_register();
?>


[EDIT BY danbrown AT php DOT net: Bugfix provided by "dr3w" on 02-APR-2010: "its [sic] function_exists with an S at the end".]
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12
rob at akrabat dot com
8 years ago
if you remove session_register() calls and replace with $_SESSION assignments, make sure that it wasn't being used in place of session_start(). If it was, you'll need to add a call to session_start() too, before you assign to $_SESSION.
up
3
david dot demri at gmail dot com
8 years ago
If you have an old code with a lot of call to the function session_register(), and you would like to make it compatible with PHP5 or PHP6, instead of rewriting all your code by replacing this function by $_SESSION['var']="val"; you could use the function set_session_vars(), that is used exactly the same way than session_register() (but there is no implicit call to session_start() ).

<?php
function set_session_vars() {
   
$nb_args=func_num_args();
   
$arg_list=func_get_args();
    for(
$i=0;$i<$nb_args;$i++) {
        global $
$arg_list[$i];
       
$_SESSION[$arg_list[$i]] = $$arg_list[$i];
    }
}
?>
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2
dee dot earley at icode dot co dot uk
1 year ago
Something that hasn't really been touch on when migrating old code, is that changes to variables made AFTER the session_register() call are still included in the session state.
A lot of the implementations above only add the entry to $_SESSION[] at the point it's called.
If the old code relies on this behaviour, you will either need to have code called on exit to assign back to $_SESSION, or replace it in entirety with $_SESSION usage. With over 1000 uses of the session_ functions, this is a bit daunting!
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1
mikej
13 years ago
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.
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1
pike-php at kw dot nl
5 months ago
There are a few compat functions for session_register here that had me tripped up.

1) when registering a session var, the value of the global you are registering should *not* override an existing session value. that would defeat the purpose of the session. instead the global should be refered to the sessions value.

2) the global should become a reference to the sessions value, so that when you change the globals value later, the session variable should change too.

This is what I'm using now

<?php
if (!function_exists('session_register')) {
     function
session_register($name){
        global $
$name;
        if (!isset(
$_SESSION[$name])) {
           
$_SESSION[$name] = $$name;
          }
          $
$name = &$_SESSION[$name];
      }
    }
?>
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0
david dot jufer at kirchenweb dot ch
1 year ago
This code replaces the removed function "session_register" for PHP >= 5.4.0
"session_start()" must be called before.

<?php

function session_register($name){
    if(isset(
$GLOBALS[$name])) $_SESSION[$name] = $GLOBALS[$name];
   
$GLOBALS[$name] = &$_SESSION[$name];
}

?>
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0
Scarab
8 years ago
If you want to store an  object into the session, you have to check up that object can be serialized at all.
For example, if your object contains aggregated PDO object (which can't be serialized), you will get an error and no data would be stored.
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-1
yarco dot w at gmail dot com
7 years ago
You *MUST* notice that

session_register($var)

*IS NOT*

$_SESSION[$var] = $$var;

it is

if (!isset($_SESSION[$var]))
  $_SESSION[$var] = $$var;

when migrating from old style code.
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-2
tecnico at overant dot com
4 years ago
If you have many websites with these functions in the source code (like me) you can include the following functions in some kind of include.php that you have:

function session_register($session)
{
  //
}

function session_unregister($session)
{
  unset($_SESSION[$session]);
}

In this way the PHP interpreter detects the functions and do not return the error, and the maintenance work is minimized.
up
-2
baldanders
13 years ago
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.
up
-2
klein at sup4u dot de
6 years ago
in addition to function set_session_vars instead of replacing all $var with $_SESSION['var'],
you could get all set session-vars in prevoius scripts with this function

<?php
function get_session_vars() {
   
$nb_args=func_num_args();
   
$arg_list=func_get_args();
    for(
$i=0;$i<$nb_args;$i++) {
        global $
$arg_list[$i] = $_SESSION[$arg_list[$i]];
    }
}
?>
up
-2
martijn at brothersinart dot net
11 years ago
Please note that if you use a "|" sign in a variable name your entire session will be cleared, so the example below will clear out all the contents of your session.

<?php
session_start
();
$_SESSION["foo|bar"] = "foo";
?>

It took me quite some time finding out why my session data kept disappearing. According to this bugreport this behaviour is intended.
http://bugs.php.net/bug.php?id=33786
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-5
guideng at unlv dot nevada dot edu
11 years ago
Make sure you put session_start() at the beggining of your script.

My sessions kept unsetting and I finally figured out why.

On my script, session_start() has to be said and uses cookies to set the session.

But I was outputting html prior to calling session_start(), which prevented it from succeeding becouse it uses the header function to place the cookies.

Once html has been outputed, session_start() can't use the header function to set cookies, hence session_start() fails and no session can be started.
up
-5
kavih7 at yahoo dot com
8 years ago
For those of you who use this function (session_register that is), even though the manual does specify that this function implicitly calls session_start(), I just wanted to reiterate that fact. It is also important to know that if you ever switch from session_register to using $_SESSION, make sure to call session_start before adding items to the $_SESSION variable, because unlike session_register, no implicit call to session_start is done.

Another reason I explain this is because I ran into a problem in which you can add items to the $_SESSION variable all you want, but if session_start is not called before adding them, they will not actually be saved to the session. Using the same code, though, and replacing the $_SESSION assignments with session_register without calling session_start WILL save that info to the session.

It would be nice to have PHP check for writes to the $_SESSION variable and complain with a warning if session_start hasn't been called.
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