---------- php debug ----------
Server=localhost;DataBase=mysql;UserID=root;PassWord=123456
resource(5) of type (mysql result)

Output completed (1 sec consumed) - Normal Termination

<?php
class DBCLS
{

 //debug 调试开关
 var $debug = true;

 //debuginfo 错误信息，调试信息
 var $debuginfo = "debug informations:\r\n";

 //db_server MySQL主机地址
 var $db_server;

 //db_name 数据库名
 var $db_name;

 //db_user 数据库用户名
 var $db_user;

 //db_passwd 密码
 var $db_passwd;

 //db_links  数据库连接
 var $db_link;

 //db_query_sql SQL语句
 var $db_query_sql = "show tables";

 //db_recordset 结果集，记录集
 var $db_recordset;

 //ready        就绪开关
 var $conntstr_ready = false;
 var $link_ready = false;
 var $db_ready = false;

 //set or return Connection String  返回，或者设定连接字符串
 function connection_string($connstr="")
 {
  if("" == $connstr)
  {
   //如果没有参数传入，返回已有的连接字符
   return "Server=".$this->db_server.";DataBase=".$this->db_name.";UserID=".$this->db_user.";PassWord=".$this->db_passwd;
  }
  else
  {
   //否则，解析连接字符，初始化变量
   preg_match_all("|([a-zA-Z0-9]*)=([a-zA-Z0-9]*);*|", $connstr,   $tmparr, PREG_PATTERN_ORDER);
   $this->db_server = (strtolower($tmparr[1][0]) == "server")?$tmparr[2][0]:"";
   $this->db_name   = (strtolower($tmparr[1][1]) == "database")?$tmparr[2][1]:"";
   $this->db_user   = (strtolower($tmparr[1][2]) == "userid")?$tmparr[2][2]:"";
   $this->db_passwd = (strtolower($tmparr[1][3]) == "password")?$tmparr[2][3]:"";
   //var_dump($tmparr);

   if("" == $this->db_server or "" == $this->db_name or "" == $this->db_user or "" == $this->db_passwd)
    $this->conntstr_ready = false; //如果有其中一个以上变量被赋以空字符串"",准备未就绪
   else
    $this->conntstr_ready = true;
   return $this->conntstr_ready;
  }

 }

 //连接数据库，返回连接对象
 function connect()
 {
  if(!$this->conntstr_ready)
  {
   if($this->debug){$this->debuginfo .= "连接字符串无效！\r\n";}
   return $this->link_ready;
  }
  if($this->db_link = @mysql_connect($this->db_server, $this->db_user, $this->db_passwd))
  {
   $this->link_ready = true;
   return $this->link_ready;