javascript - 如何防止用户通过 PHP 而不是 jQuery 在输入框中键入特殊字符？

Question

我有一个带有 3 个输入框的表单，如下所示:

echo '<form action="" name="frm_chg_pass" method="post">';
echo '<tr ><td class="td1">Dear user</td></tr>';
echo '<tr ><td class="td1"><p>'.$prs_name."  ".$prs_family.'</td></tr>';
echo '<tr><td class="td1">you will change your pass word please be careful for keeping it  </td></tr>';
echo '<tr><td class="td1">you dont allow for type these charecter: & > < / "'."'".' ; : )= ( ] [ # } { \ .</p></td></tr>';
echo '<tr><td class="td1"><input type="text" id="id_pass_old" name="pass_old" onselectstart="return false" onpaste="return false;" onCopy="return false" onCut="return false" onDrag="return false" onDrop="return false" required="required" autocomplete="off"     /></td><td class="td1"><p>Old Password</p></td>';
echo '<tr><td class="td1"><input type="password" id="id_pass_new" name="pass_new" onselectstart="return false" onpaste="return false;" onCopy="return false" onCut="return false" onDrag="return false" onDrop="return false" required="required" autocomplete="off" /></td><td class="td1"><p>New Password</p></td>';
echo '<tr><td class="td1"><input type="password" id="id_pass_conf" name="pass_conf" onselectstart="return false" onpaste="return false;" onCopy="return false" onCut="return false" onDrag="return false" onDrop="return false" required="required"  autocomplete="off"/></td><td class="td1"><p>Confirm new password</p></td>';
echo '<tr><td class="td1"><input type="submit" name="btn_change_pass" method="post" value="RegisterChang"/></td></tr>';
echo '</form>';

如你所见，我不希望用户插入 & > < / "' ; : ) = ( ] [ # } { \在输入框中，不要使用 JavaScript 进行检查。我怎样才能防止 PHP 键入这些内容？

Answer 1

您可以在表单的操作中进行服务器端验证。它应该是这样的:

if (isset($_POST['submit'])) {
    if (!ctype_alnum($_POST['INPUTNAME'])) {
        $error .= 'Input data should be alpha numeric characters only.';
    }
}