安全脚本：在应用前将值设为小写并删除空格

Question

在我的注册页面上，我有一个用户必须回答的安全问题。它运行良好，并且阻止了垃圾邮件机器人。

这是脚本（非常轻量级）：

add_action( 'register_form', 'add_register_field' );
function add_register_field() { ?>
    <p>
        <label><?php _e('What is the name of the ship in the TV show Firefly?') ?><br />
            <input type="text" name="user_proof" id="user_proof" class="input" size="25" tabindex="20" /></label>
    </p>
<?php }

add_action( 'register_post', 'add_register_field_validate', 10, 3 );
function add_register_field_validate( $sanitized_user_login, $user_email, $errors) {
    if (!isset($_POST[ 'user_proof' ]) || empty($_POST[ 'user_proof' ])) {
        return $errors->add( 'proofempty', '<strong>ERROR</strong>: You did not answer the proof-of-humanship question.'  );
    } elseif ( strtolower( $_POST[ 'user_proof' ] ) != 'serenity' ) {
        return $errors->add( 'prooffail', '<strong>ERROR</strong>: You did not answer the proof-of-humanship question correctly.'  );
    }
}

下面是它的外观图片：

所以用户必须输入的答案是serenity。问题是有些用户将其输入为Serenity，或者在某处添加了一个随机空格。

我的问题是，我怎样才能使他们输入的值转换为小写字母，并在检查值是否正确之前删除所有空格？这样，如果他们输入Ser enItY，就可以了。

Answer 1

使用str_replace(' ', '', $string) 删除空格； trim($string) 删除输入周围的任何其他“垃圾”； strtolower($string) 获取小写字符串。比较字符串使用 strcmp($string, $string1) 最后你得到：

if (strcmp('serenity', strtolower(str_replace(' ', '', trim($_POST['user_proof'])))) == 0)

在您的代码中：

function add_register_field_validate($sanitized_user_login, $user_email, $errors) {
    if (empty($_POST['user_proof'])) {
        return $errors->add('proofempty', '<strong>ERROR</strong>: You did not answer the proof-of-humanship question.' );
    } elseif (strcmp('serenity', strtolower(str_replace(' ', '', trim($_POST['user_proof'])))) != 0) {
        return $errors->add('prooffail', '<strong>ERROR</strong>: You did not answer the proof-of-humanship question correctly.' );
    }
}

Answer 2

$user_proof = $_POST[ 'user_proof' ]; // this is the form field being posted.
$user_proof = strtolower($user_proof); // this will convert it to lower case
$user_proof = str_replace(" ", "", $user_proof); // this will remove spaces in string

EIDT：根据您的要求：

function add_register_field_validate( $sanitized_user_login, $user_email, $errors) 
{
   if (!isset($_POST[ 'user_proof' ]) || empty($_POST[ 'user_proof' ])) 
   {
    return $errors->add( 'proofempty', '<strong>ERROR</strong>: You did not answer the proof-of-humanship question.'  );
   } 

   $user_proof = $_POST[ 'user_proof' ]; // this is the form field being posted.
   $user_proof = strtolower($user_proof); // this will convert it to lower case
   $user_proof = str_replace(" ", "", $user_proof); // this will remove spaces in string

   if ( $user_proof != 'serenity' ) 
   {
    return $errors->add( 'prooffail', '<strong>ERROR</strong>: You did not answer the proof-of-humanship question correctly.'  );
   }
}

Answer 3

if($input != 'serenity'){
    //Show errors
}

function add_register_field_validate( $sanitized_user_login, $user_email, $errors) {


    if (!isset($_POST[ 'user_proof' ]) || empty($_POST[ 'user_proof' ])) {
        return $errors->add( 'proofempty', '<strong>ERROR</strong>: You did not answer the proof-of-humanship question.'  );
    } elseif (strtolower(str_replace(' ', '', strip_tags(stripslashes($_POST['user_proof'])))) != 'serenity' ) {
        return $errors->add( 'prooffail', '<strong>ERROR</strong>: You did not answer the proof-of-humanship question correctly.'  );
    }
}