PHP secondary domain name session sharing scheme

Generally speaking, websites will have master stations and sub stations , For example, the domain name is linuxidc.com, So in general linuxidc.com and www.linuxidc.com It will be the main station , And like bbs.linuxidc.com Will exist as a sub station of the Forum .

And pay attention to , Although the domain name is generally set dns When parsing , Will be linuxidc.com and www.linuxidc.com It is set to point to the home page, although the effect looks the same . But these two are really different domain names , That is, if it is the default , These two domain names cookie Of domain Think differently .

In general , If the website has user login function , We generally hope that no matter what kind of secondary domain name , They all maintain this login status .

therefore , In order to solve this secondary domain name session Sharing issues , The following scheme is recommended ：

<?phpini_set("session.cookie_domain",'linuxidc.com');// notes ： This sentence must be placed in session_start() Before session_start();

It should be noted that ：

1、ini_set("session.cookie_domain",'linuxidc.com'); Must be on session_start(); Before .

2、 domain name linuxidc.com It must match the domain name actually accessed by the browser .

In fact, it's very simple , That is, the primary domain name and the secondary domain name domain Set as the primary domain name , In this way... Can be achieved session Shared access between different secondary domain names .

Ps. stay PHP Of CI In the frame , If you want to realize its own Session Classes can be shared in different secondary domain names , It's in /application/config/config.php In file , Make the following settings ：

$config['cookie_domain'] = "linuxidc.com";