php实现session自定义会话处理器的方法

function open($save_path,$session_name)
{
? global $sess_save_path;
? $sess_save_path = $save_path;
? return(true);
}

function close()
{
? return(true);
}

function read($id)
{
? global $sess_save_path;
? $sess_file = "$sess_save_path/sess_$id";
? return (string) @file_get_contents($sess_file);
}

function write($id,$sess_data)
{
? global $sess_save_path;
? $sess_file = "$sess_save_path/sess_$id";
? if ($fp = @fopen($sess_file,"w")) {
??? $return = fwrite($fp,$sess_data);
??? fclose($fp);
??? return $return;
? } else {
??? return(false);
? }
}

function destroy($id)
{
? global $sess_save_path;
? $sess_file = "$sess_save_path/sess_$id";
? return(@unlink($sess_file));
}

function gc($maxlifetime)
{
? global $sess_save_path;
? foreach (glob("$sess_save_path/sess_*") as $filename) {
??? if (filemtime($filename) + $maxlifetime < time()) {
????? @unlink($filename);
??? }
? }
? return true;
}

session_set_save_handler("open","close","read","write","destroy","gc");
session_start();
// proceed to use sessions normally
?>