php - PHP：正则表达式只有字母数字和一些特殊字符

Question

我想使用正则表达式来限制允许的字符。那是：

a - z /* a to z */
A - Z /* A to Z */
0 - 9 /* 0 to 9 */
_ - /* underscore & dash */
~ ! @ # $% ^ & * () /* allowed special characters */

这是我的正则表达式函数：

function validChr($str) {
    return preg_match('/^[A-Za-z0-9_~\-!@#\$%\^&*\(\)]+$/',$str);
}

我实际上已经尝试过它并获得了我想要的结果，但我仍然不确定。我的正则表达式是否正确？还是有其他形式的正则表达式？请帮忙，因为我对这个正则表达式还是新手。谢谢你。

Answer 1

它可以正常工作。

您应该只在 * 之前添加 \ 来转义它。

在这里查看：正则表达式测试

Answer 2

你可以使用我前一段时间做的这个函数来输入密码。您可以通过修改 if 条件将其用于任何字符串。把每个特殊字符用\放在前面。它还检查字符串是否为 8-20 个字符长

    function isPasswordValid($password){
            $whiteListed = "\$\@\#\^\|\!\~\=\+\-\_\.";
            $status = false;
            $message = "Password is invalid";
            $containsLetter  = preg_match('/[a-zA-Z]/', $password);
            $containsDigit   = preg_match('/\d/', $password);
            $containsSpecial = preg_match('/['.$whiteListed.']/', $password);
            $containsAnyOther = preg_match('/[^A-Za-z-\d'.$whiteListed.']/', $password);
            if (strlen($password) < 8 ) $message = "Password should be at least 8 characters long";
            else if (strlen($password) > 20 ) $message = "Password should be at maximum 20 characters long";
            else if(!$containsLetter) $message = "Password should contain at least one letter.";
            else if(!$containsDigit) $message = "Password should contain at least one number.";
            else if(!$containsSpecial) $message = "Password should contain at least one of these ".stripslashes( $whiteListed )." ";
            else if($containsAnyOther) $message = "Password should contain only the mentioned characters";
            else {
                $status = true;
                $message = "Password is valid";
            }
            return array(
                "status" => $status,
                "message" => $message
            );
    }

输出

$password = "asdasdasd"
print_r(isPasswordValid($password));
// [
//   "status"=>false,
//   "message" => "Password should contain at least one number."
//]

$password = "asdasd1$asd"
print_r(isPasswordValid($password));
// [
//   "status"=>true,
//   "message" => "Password is valid."
//]