Description
bool 
session_regenerate_id ( void )
     session_regenerate_id() will replace the current
     session id with a new one, and keep the current session information.
    
     如果成功则返回 TRUE,失败则返回 FALSE。
    
     
例子 1. A session_regenerate_id() example 
<?php session_start();
  $old_sessionid = session_id();
  session_regenerate_id();
  $new_sessionid = session_id();
  echo "Old Session: $old_sessionid<br />"; echo "New Session: $new_sessionid<br />";
  print_r($_SESSION); ?>
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  | 
    注: 
      As of PHP 4.3.3, if session cookies are enabled, use of
      session_regenerate_id() will also submit a new
      session cookie with the new session id.
     
     See also session_id(),
     session_start(), and 
     session_name().