if you try to name a php session "example.com" it gets converted to "example_com" and everything breaks.
don't use a period in your session name.
session_name
(PHP 4, PHP 5)
session_name — 現在のセッション名を取得または設定する
説明
string session_name
([ string $name
] )
session_name() は、現在のセッション名を返します。
セッション名は、リクエストが開始された際に セッション名に保存された session.name の デフォルト値にリセットされます。よって、各リクエスト毎に(そして session_start() または session_register() をコールする前に) session_name() をコールする必要があります。
パラメータ
- name
-
セッション名は、クッキーおよび URL のセッション ID を参照します。 セッション名は英数字のみで構成されている必要があり、また、 短く、その内容が分かるようなものである必要があります (これは、クッキー警告を有効にしているユーザ用です)。
警告セッション名は数字だけで構成することはできません。 少なくとも文字がひとつ以上現れる必要があります。そうでない場合、 新規セッション ID が毎回生成されます。
返り値
現在のセッションの名前を返します。
例
例1 session_name() の例
<?php
/* セッション名をWebsiteIDに設定する */
$previous_name = session_name("WebsiteID");
echo "前回のセッション名は、$previous_name です。<br />";
?>
session_name
php at wiz dot cx
28-Sep-2008 12:36
28-Sep-2008 12:36
Molot
22-Sep-2008 05:39
22-Sep-2008 05:39
@Hongliang Qiang
You may close the session by hand, then set name, and start session. "quick and dirty" solution to php.ini problem.
I don't know if this config var can be override in any other way. Not from the code, certainly, as session is already started when the first line is executed.
xemc at yahoo dot com
27-Aug-2008 05:20
27-Aug-2008 05:20
Here's a sample program I made to explore the operation of the session stuff. One thing I wanted to do was switch sessions in the middle of a script - where session_name doesn't automatically create or resume the corresponding session id... (anyone have a better idea?)
<?php
if ( $_REQUEST['sname'] ) {
session_name($_REQUEST['sname']);
}
session_start();
$messages = "";
function show( $str ) { global $messages; $messages .= $str; }
function show_sess_vars() {
foreach ( $_SESSION as $key => $val ) {
show("Session var '$key': \t'$val'\n");
}
}
show("Session name: \t" . session_name() . "\n");
show("Session ID: \t" . session_id() . "\n");
foreach ( $_REQUEST as $key => $val ) {
if ( $key == 'regenerate' )
{
session_regenerate_id();
show("session_regenerate_id();\n");
show("Session name: \t" . session_name() . "\n");
show("Session ID: \t" . session_id() . "\n");
}
else if ( $key == 'clear' )
{
$_SESSION = array();
show("\$_SESSION = array();\n");
}
else if ( $key == 'switch' )
{
show("Will attempt to switch session name.. vars:\n");
show_sess_vars();
session_write_close();
$res = session_name($val);
show("session_name($val) - res: $res\n");
session_start();
show("Session name: \t" . session_name() . "\n");
show("Session ID: \t" . session_id() . "\n");
}
else if ( $key == 'switch2' )
{
show("Will attempt to switch session name.. vars:\n");
show_sess_vars();
session_write_close();
show("session_write_close();\n");
$sess_id = $_COOKIE[$val];
if ( $sess_id ) {
show("session '$val' exists, resuming..\n");
//unset($_SESSION); // to make sure - this should be reloaded below
session_name( $val );
session_id( $sess_id );
session_start(); // fills $_SESSION from the named session
} else {
show("creating new session '$val'...\n");
session_name( $val );
session_start();
session_regenerate_id(); // create new (copy of old), leave old alone
$_SESSION = array(); // wipe data clean for a fresh session
show("regenerated ID and wiped SESSION superglobal\n");
}
show("Session name: \t" . session_name() . "\n");
show("Session ID: \t" . session_id() . "\n");
}
else
{
if ( $_COOKIE[$key] ) {
show("Cookie: \t'$key': \t'$val'\n");
} else {
show("Setting session var: \t'$key': \t'$val'\n");
$_SESSION[$key] = $val;
}
}
}
show("----\nSession vars:\n");
show_sess_vars();
if ( false ) {
session_write_close();
session_name("edit_assembly");
session_start();
show("Session name: \t" . session_name() . "\n");
show("Session ID: \t" . session_id() . "\n");
show_sess_vars();
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
<head>
<title> PHP session testing </title>
<style type='text/css'>
body { background-color: gray; }
#content { background-color: white; width: 70%; margin: 1em auto 1em auto; padding: 2em;
font-family: Verdana, monospace; font-size: 10pt; }
</style>
</head>
<body>
<div id='content'>
<h1> PHP session test: </h1>
<pre><?php echo $messages; ?></pre>
</div>
</body>
</html>
webmaster at nncoders dot de
27-Jun-2008 01:29
27-Jun-2008 01:29
You can always just use "or".
@foo or bar();
When foo fails, (and the at still means don't print an error to the browser), the function bar will be executed.
<?php
function errorhandler () { /* do something wild */ }
@session_name('mysession') or errorhandler();
?>
Another live example would be
@mysql_query('show databases') or die(mysql_error());
When the execution fails, parameter die is called (with last mysql_error as given string parameter)
php at REMOVETHIS dot kennel17 dot co dot uk
27-Jun-2005 11:47
27-Jun-2005 11:47
In response to codegrunt slave, you could suppress any warnings from being output by using the @ symbol.
<?php
// This will fail, but no message will be output:
@session_name("(bad name)");
?>
Alternatively, you could use output buffering instead of the @ symbol if you wanted to check whether an error occurred.
<?php
ob_start();
session_name("(bad name)");
$Output = ob_get_contents();
ob_end_clean();
if ($Output != "")
print("Bad session name!");
?>
slave at codegrunt dot com
23-Dec-2004 07:03
23-Dec-2004 07:03
One gotcha I have noticed with session_name is that it will trigger a WARNING level error if the cookie or GET/POST variable value has something other than alphanumeric characters in it. If your site displays warnings and uses PHP sessions this may be a way to enumerate at least some of your scripts:
http://example.com/foo.php?session_name_here=(bad)
Warning: session_start(): The session id contains invalid characters, valid characters are only a-z, A-Z and 0-9 in /some/path/foo.php on line 666
I did not see anything in the docs suggesting that one had to sanitize the PHP session ID values before opening the session but that appears to be the case.
Unfortunately session_name() always returns true so you have to actually get to the point of assigning variables values before you know whether you have been passed bad session data (as far as I can see). After the error has been generated in other words.
Cheers
Hongliang Qiang
28-May-2004 05:48
28-May-2004 05:48
This may sound no-brainer: the session_name() function will have no essential effect if you set session.auto_start to "true" in php.ini . And the obvious explanation is the session already started thus cannot be altered before the session_name() function--wherever it is in the script--is executed, same reason session_name needs to be called before session_start() as documented.
I know it is really not a big deal. But I had a quite hard time before figuring this out, and hope it might be helpful to someone like me.