session_regenerate_id
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.
session_register
(PHP 4, PHP 5)
session_register — Register one or more global variables with the current session
说明
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.
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.";
?>
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.
参数
- name
-
A string holding the name of a variable or an array consisting of variable names or other arrays.
- ...
-
返回值
如果成功则返回 TRUE，失败则返回 FALSE。
注释
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.
Note: register_globals 重要说明 自 PHP 4.2.0 起，PHP 中的选项 register_globals 的默认值被设为 off，并且自 PHP 6.0.0 起会被彻底去除。PHP 社区鼓励大家不要依赖于这个选项，用其它方法替代，例如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().
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';
add a note
User Contributed Notessession_register
guideng at unlv dot nevada dot edu
01-Jun-2006 01:10
01-Jun-2006 01:10
martijn at brothersinart dot net
11-Apr-2006 02:04
11-Apr-2006 02:04
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
mikej
21-Nov-2004 01:40
21-Nov-2004 01:40
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 11:05
12-Nov-2004 11:05
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.