添加簡單的數學驗證碼

Question

我這個[教程]提出的驗證碼[1]，

[1]：http://codechirps.com/how-to-add-a-completely-custom-captcha-to-any-web-form/，但在我看來，它不完整。 我做了代碼，但我可以發送電子郵件，即使我提出錯誤的答案。我覺得我必須在PHP文件中編寫額外的代碼，但我不知道在哪裏。任何幫助大大appriciated

<div class="modal-body"> 
       <form class="contact" name="contact"> 
        <label class="label" for="name">Имя</label><br> 
        <input type="text" name="name" class="input-xlarge"><br> 
        <label class="label" for="email">E-mail</label><br> 
        <input type="email" name="email" class="input-xlarge"><br> 
        <label class="label" for="message">Сообщение</label><br> 
        <textarea name="message" class="input-xlarge"></textarea> 
       </form> 
      </div> 
      <div class="modal-footer"> 
         <p>2 + 3 =</p> 
         <input type="text" name="captcha" /> 
       <input class="btn btn-warning" type="submit" value="Отправить" id="submit"> 
       <a href="#" class="btn btn-danger" data-dismiss="modal">Закрыть</a> 


<?php 
$myemail = ''; 
if (isset($_POST['name'])) { 
$name = strip_tags($_POST['name']); 
$email = strip_tags($_POST['email']); 
$message = strip_tags($_POST['message']); 
$captcha = check_input($_POST['captcha']); 
echo "<span class=\"alert alert-success\" >Сообщение отправлено</span><br><br>"; 

if (!preg_match("/5/", $captcha)) 
{ 
show_error("Check your math, Dude"); 
} 


$to = $myemail; 
$email_subject = "Contact form submission: $name"; 
$email_body = "You have received a new message. ". 
" Here are the details:\n Name: $name \n ". 
"Email: $email\n Message \n $message"; 
$headers = "From: $myemail\n"; 
$headers .= "Reply-To: $email"; 
mail($to,$email_subject,$email_body,$headers); 
}?> 

Answer 1

好吧，所以你需要檢查你的輸入值，看看他們是否有效。如果沒有，則顯示錯誤並且郵件不會發送。如果所有的檢查都通過了，那麼這些女傭就會被送出去。所以你需要檢查$_POST['email']和$_POST['captcha']字段（如果你想，檢查其餘是不是空的或其他）。

在PHP中，你可以做到這一點是這樣的：

$myemail = ""; 
if(isset($_POST['name'])){ // check if a form is submitted 
    if(empty(trim($_POST['name'])) || empty(trim($_POST['message'])) || empty(trim($_POST['email'])) || empty(trim($_POST['captcha']))){ // check if values are not empty 
     echo "Please fill in all the required fields."; 
    }else if(!filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)){ // check email 
     echo "Please give a real e-mail address."; 
    }else if(!preg_match("/5/", $_POST['captcha'])){ // the code provided by your script 
     echo "Get your math right, dude!"; 
    }else{ // all fields seem to be ok 
     // sanitize input using htmlspecialchars(), see http://stackoverflow.com/a/5788361/1319187 
     $name = htmlspecialchars($_POST['email']); 
     $email = $_POST['email']; // email doesn't need to be sanitized since it's been filtered 
     $message = htmlspecialchars($_POST['message']); 

     //Send the mail 
     $to = $myemail; 
     $email_subject = "Contact form submission: $name"; 
     $email_body = "You have received a new message. ". 
      " Here are the details:\n Name: $name \n ". 
      "Email: $email\n Message \n $message"; 
     $headers = "From: $myemail\n"; 
     $headers .= "Reply-To: $email"; 
     if(mail($to,$email_subject,$email_body,$headers)){ 
      echo "Succes! Your mail has been sent!"; 
     }else{ 
      echo "Something went wrong with the sending of a mail."; 
     } 
    } 
} 

應該是相當簡單的，你可以在google的一些功能，如果你不知道他們在做什麼。我也不知道check_input()來自哪裏。這不是一個原生的PHP函數，你提供的鏈接不顯示它的功能。此外，檢查驗證碼的值是否爲5的正則表達式有點愚蠢，你可以檢查$_POST['captcha'] == '5'。另外請記住，你必須稍微隨機化這些值。