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session_regenerate_id> <session_module_name
Last updated: Fri, 27 Jun 2008

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session_name

(PHP 4, PHP 5)

session_name — Get and/or set the current session name

Description

string session_name ([ string $name ] )

session_name() returns the name of the current session.

The session name is reset to the default value stored in session.name at request startup time. Thus, you need to call session_name() for every request (and before session_start() or session_register() are called).

Parameters

name

The session name references the session id in cookies and URLs. It should contain only alphanumeric characters; it should be short and descriptive (i.e. for users with enabled cookie warnings). If name is specified, the name of the current session is changed to its value.

Warning

The session name can't consist of digits only, at least one letter must be present. Otherwise a new session id is generated every time.

Return Values

Returns the name of the current session.

Examples

Example #1 session_name() example

<?php

/* set the session name to WebsiteID */

$previous_name session_name("WebsiteID");

echo 
"The previous session name was $previous_name<br />";
?>

See Also



session_regenerate_id> <session_module_name
Last updated: Fri, 27 Jun 2008
 
add a note add a note User Contributed Notes
session_name
webmaster at nncoders dot de
26-Jun-2008 06:29
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 04:47
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
22-Dec-2004 11:03
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
27-May-2004 10:48
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.

session_regenerate_id> <session_module_name
Last updated: Fri, 27 Jun 2008
 
 
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