定制php4的session功能

定制php4的session功能(5)
if ($expires_at > time()) {
$var = substr($tmp, strpos($tmp, "¦") + 1);
}
}

return $var;
}

function sess_write($key, $val) {
global $SESS_DBM, $SESS_LIFE;

dbmreplace($SESS_DBM, $key, time() + $SESS_LIFE . "¦" . $val);
return true;
}

function sess_destroy($key) {
global $SESS_DBM;

dbmdelete($SESS_DBM, $key);
return true;
}

function sess_gc($maxlifetime) {
global $SESS_DBM;

$now = time();
$key = dbmfirstkey($SESS_DBM);
while ($key) {
if ($tmp = dbmfetch($SESS_DBM, $key)) {
$expires_at = substr($tmp, 0, strpos($tmp, "¦"));
if ($now > $expires_at) {
sess_destroy($key);
}
}

$key = dbmnextkey($SESS_DBM, $key);
}
}

session_set_save_handler(
"sess_open",
"sess_close",
"sess_read",
"sess_write",
"sess_destroy",
"sess_gc");
?>
=====================================================================================
session_mysql.php
=======================================================================================
<?
/* ------------------------------------------------------------------------
* session_mysql.php
* ------------------------------------------------------------------------
* PHP4 MySQL Session Handler
* Version 1.00
* by Ying Zhang (ying@zippydesign.com)
* Last Modified: May 21 2000
*
* ------------------------------------------------------------------------
* TERMS OF USAGE:
* ------------------------------------------------------------------------
* You are free to use this library in any way you want, no warranties are
* expressed or implied. This works for me, but I don't guarantee that it
* works for you, USE AT YOUR OWN RISK.
*
* While not required to do so, I would appreciate it if you would retain