PHP simple method to implement member password retrieval function

<p><strong>输入您注册的电子邮箱，找回密码：</strong></p> 
<p><input type="text" class="input" name="email" id="email"><span id="chkmsg"></span></p> 
<p><input type="button" class="btn" id="sub_btn" value="提 交"></p>

$(function(){ 
$("#sub_btn").click(function(){ 
var email = $("#email").val(); 
var preg = /^w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*/; //匹配Email 
if(email=='' || !preg.test(email)){ 
$("#chkmsg").html("请填写正确的邮箱！"); 
}else{ 
$("#sub_btn").attr("disabled","disabled").val('提交中..').css("cursor","default"); 
$.post("sendmail.php",{mail:email},function(msg){ 
if(msg=="noreg"){ 
$("#chkmsg").html("该邮箱尚未注册！"); 
$("#sub_btn").removeAttr("disabled").val('提 交').css("cursor","pointer"); 
}else{ 
$(".demo").html("<h3>"+msg+"</h3>"); 
} 
}); 
} 
}); 
})

include_once("connect.php");//连接数据库 

$email = stripslashes(trim($_POST['mail'])); 

$sql = "select id,username,password from `t_user` where `email`='$email'"; 
$query = mysql_query($sql); 
$num = mysql_num_rows($query); 
if($num==0){//该邮箱尚未注册！ 
echo 'noreg'; 
exit; 
}else{ 
$row = mysql_fetch_array($query); 
$getpasstime = time(); 
$uid = $row['id']; 
$token = md5($uid.$row['username'].$row['password']);//组合验证码 
$url = "/demo/resetpass/reset.php?email=".$email." 
&token=".$token;//构造URL 
$time = date('Y-m-d H:i'); 
$result = sendmail($time,$email,$url); 
if($result==1){//邮件发送成功 
$msg = &#39;系统已向您的邮箱发送了一封邮件<br/>请登录到您的邮箱及时重置您的密码！&#39;; 
//更新数据发送时间 
mysql_query("update `t_user` set `getpasstime`=&#39;$getpasstime&#39; where id=&#39;$uid &#39;"); 
}else{ 
$msg = $result; 
} 
echo $msg; 
} 

//发送邮件 
function sendmail($time,$email,$url){ 
include_once("smtp.class.php"); 
$smtpserver = ""; //SMTP服务器，如smtp.163.com 
$smtpserverport = 25; //SMTP服务器端口 
$smtpusermail = ""; //SMTP服务器的用户邮箱 
$smtpuser = ""; //SMTP服务器的用户帐号 
$smtppass = ""; //SMTP服务器的用户密码 
$smtp = new Smtp($smtpserver, $smtpserverport, true, $smtpuser, $smtppass); 
//这里面的一个true是表示使用身份验证,否则不使用身份验证. 
$emailtype = "HTML"; //信件类型，文本:text；网页：HTML 
$smtpemailto = $email; 
$smtpemailfrom = $smtpusermail; 
$emailsubject = "www.jb51.net - 找回密码"; 
$emailbody = "亲爱的".$email."：<br/>您在".$time."提交了找回密码请求。请点击下面的链接重置密码 
（按钮24小时内有效）。<br/><a href=&#39;".$url."&#39;target=&#39;_blank&#39;>".$url."</a>"; 
$rs = $smtp->sendmail($smtpemailto, $smtpemailfrom, $emailsubject, $emailbody, $emailtype); 

return $rs; 
}

include_once("connect.php");//连接数据库 

$token = stripslashes(trim($_GET['token'])); 
$email = stripslashes(trim($_GET['email'])); 
$sql = "select * from `t_user` where email='$email'"; 

$query = mysql_query($sql); 
$row = mysql_fetch_array($query); 
if($row){ 
$mt = md5($row['id'].$row['username'].$row['password']); 
if($mt==$token){ 
if(time()-$row['getpasstime']>24*60*60){ 
$msg = '该链接已过期！'; 
}else{ 
//重置密码... 
$msg = &#39;请重新设置密码，显示重置密码表单，<br/>这里只是演示，略过。&#39;; 
} 
}else{ 
$msg = &#39;无效的链接&#39;; 
} 
}else{ 
$msg = &#39;错误的链接！&#39;; 
} 
echo $msg;

CREATE TABLE `t_user` ( 
`id` int(11) NOT NULL auto_increment, 
`username` varchar(30) NOT NULL, 
`password` varchar(32) NOT NULL, 
`email` varchar(50) NOT NULL, 
`getpasstime` int(10) NOT NULL, 
PRIMARY KEY (`id`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

<?php

class Smtp{

/* Public Variables */

var $smtp_port;

var $time_out;

var $host_name;

var $log_file;

var $relay_host;

var $debug;

var $auth;

var $user;

var $pass;

/* Private Variables */
var $sock;

/* Constractor */

function smtp($relay_host = "", $smtp_port = 25, $auth = false, $user, $pass) {
$this->debug = false;

$this->smtp_port = $smtp_port;

$this->relay_host = $relay_host;

$this->time_out = 30; //is used in fsockopen()

$this->auth = $auth; //auth

$this->user = $user;

$this->pass = $pass;

$this->host_name = "localhost"; //is used in HELO command
$this->log_file = "";

$this->sock = false;
}

/* Main Function */

function sendmail($to, $from, $subject = "", $body = "", $mailtype, $cc = "", $bcc = "", $additional_headers = "") {
$mail_from = $this->get_address($this->strip_comment($from));

$body = ereg_replace("(^|(rn))(.)", "1.3", $body);

$header .= "MIME-Version:1.0rn";

if ($mailtype == "HTML") {
$header .= "Content-Type:text/htmlrn";
}

$header .= "To: " . $to . "rn";

if ($cc != "") {
$header .= "Cc: " . $cc . "rn";
}

$header .= "From(www.jb51.net): $from<" . $from . ">rn";

$header .= "Subject: " . $subject . "rn";

$header .= $additional_headers;

$header .= "Date: " . date("r") . "rn";

$header .= "X-Mailer:By Redhat (PHP/" . phpversion() . ")rn";

list ($msec, $sec) = explode(" ", microtime());

$header .= "Message-ID: <" . date("YmdHis", $sec) . "." . ($msec * 1000000) . "." . $mail_from . ">rn";

$TO = explode(",", $this->strip_comment($to));

if ($cc != "") {
$TO = array_merge($TO, explode(",", $this->strip_comment($cc)));
}

if ($bcc != "") {
$TO = array_merge($TO, explode(",", $this->strip_comment($bcc)));
}

$sent = true;

foreach ($TO as $rcpt_to) {
$rcpt_to = $this->get_address($rcpt_to);

if (!$this->smtp_sockopen($rcpt_to)) {
$this->log_write("Error: Cannot send email to " . $rcpt_to . "n");

$sent = false;

continue;
}

if ($this->smtp_send($this->host_name, $mail_from, $rcpt_to, $header, $body)) {
$this->log_write("E-mail has been sent to <" . $rcpt_to . ">n");
} else {
$this->log_write("Error: Cannot send email to <" . $rcpt_to . ">n");

$sent = false;
}

fclose($this->sock);

$this->log_write("Disconnected from remote hostn");
}

return $sent;
}

/* Private Functions */

function smtp_send($helo, $from, $to, $header, $body = "") {
if (!$this->smtp_putcmd("HELO", $helo)) {
return $this->smtp_error("sending HELO command");
}
// auth
if ($this->auth) {
if (!$this->smtp_putcmd("AUTH LOGIN", base64_encode($this->user))) {
return $this->smtp_error("sending HELO command");
}

if (!$this->smtp_putcmd("", base64_encode($this->pass))) {
return $this->smtp_error("sending HELO command");
}
}

if (!$this->smtp_putcmd("MAIL", "FROM:<" . $from . ">")) {
return $this->smtp_error("sending MAIL FROM command");
}

if (!$this->smtp_putcmd("RCPT", "TO:<" . $to . ">")) {
return $this->smtp_error("sending RCPT TO command");
}

if (!$this->smtp_putcmd("DATA")) {
return $this->smtp_error("sending DATA command");
}

if (!$this->smtp_message($header, $body)) {
return $this->smtp_error("sending message");
}

if (!$this->smtp_eom()) {
return $this->smtp_error("sending <CR><LF>.<CR><LF> [EOM]");
}

if (!$this->smtp_putcmd("QUIT")) {
return $this->smtp_error("sending QUIT command");
}

return true;
}

function smtp_sockopen($address) {
if ($this->relay_host == "") {
return $this->smtp_sockopen_mx($address);
} else {
return $this->smtp_sockopen_relay();
}
}

function smtp_sockopen_relay() {
$this->log_write("Trying to " . $this->relay_host . ":" . $this->smtp_port . "n");

$this->sock = @ fsockopen($this->relay_host, $this->smtp_port, $errno, $errstr, $this->time_out);

if (!($this->sock && $this->smtp_ok())) {
$this->log_write("Error: Cannot connenct to relay host " . $this->relay_host . "n");

$this->log_write("Error: " . $errstr . " (" . $errno . ")n");

return false;
}

$this->log_write("Connected to relay host " . $this->relay_host . "n");

return true;
;
}

function smtp_sockopen_mx($address) {
$domain = ereg_replace("^.+@([^@]+)$", "1", $address);

if (!@ getmxrr($domain, $MXHOSTS)) {
$this->log_write("Error: Cannot resolve MX "" . $domain . ""n");

return false;
}

foreach ($MXHOSTS as $host) {
$this->log_write("Trying to " . $host . ":" . $this->smtp_port . "n");

$this->sock = @ fsockopen($host, $this->smtp_port, $errno, $errstr, $this->time_out);

if (!($this->sock && $this->smtp_ok())) {
$this->log_write("Warning: Cannot connect to mx host " . $host . "n");

$this->log_write("Error: " . $errstr . " (" . $errno . ")n");

continue;
}

$this->log_write("Connected to mx host " . $host . "n");

return true;
}

$this->log_write("Error: Cannot connect to any mx hosts (" . implode(", ", $MXHOSTS) . ")n");

return false;
}

function smtp_message($header, $body) {
fputs($this->sock, $header . "rn" . $body);

$this->smtp_debug("> " . str_replace("rn", "n" . "> ", $header . "n> " . $body . "n> "));

return true;
}

function smtp_eom() {
fputs($this->sock, "rn.rn");

$this->smtp_debug(". [EOM]n");

return $this->smtp_ok();
}

function smtp_ok() {
$response = str_replace("rn", "", fgets($this->sock, 512));

$this->smtp_debug($response . "n");

if (!ereg("^[23]", $response)) {
fputs($this->sock, "QUITrn");

fgets($this->sock, 512);

$this->log_write("Error: Remote host returned "" . $response . ""n");

return false;
}

return true;
}

function smtp_putcmd($cmd, $arg = "") {
if ($arg != "") {
if ($cmd == "")
$cmd = $arg;

else
$cmd = $cmd . " " . $arg;
}

fputs($this->sock, $cmd . "rn");

$this->smtp_debug("> " . $cmd . "n");

return $this->smtp_ok();
}

function smtp_error($string) {
$this->log_write("Error: Error occurred while " . $string . ".n");

return false;
}

function log_write($message) {
$this->smtp_debug($message);

if ($this->log_file == "") {
return true;
}

$message = date("M d H:i:s ") . get_current_user() . "[" . getmypid() . "]: " . $message;

if (!@ file_exists($this->log_file) || !($fp = @ fopen($this->log_file, "a"))) {
$this->smtp_debug("Warning: Cannot open log file "" . $this->log_file . ""n");

return false;
;
}

flock($fp, LOCK_EX);

fputs($fp, $message);

fclose($fp);

return true;
}

function strip_comment($address) {
$comment = "([^()]*)";

while (ereg($comment, $address)) {
$address = ereg_replace($comment, "", $address);
}

return $address;
}

function get_address($address) {
$address = ereg_replace("([ trn])+", "", $address);

$address = ereg_replace("^.*<(.+)>.*$", "1", $address);

return $address;
}

function smtp_debug($message) {
if ($this->debug) {
echo $message . "
;";
}
}
}
?>