networking - 主机名的有效字符？

Question

主机名的有效字符是什么？这类似于联网计算机或网络域。

为了说明这一点，我正在编写一个连接到远程服务器的 PC 游戏；所以我有一个主机名字段和一个端口字段。显然，端口是短范围内的数字，但我需要知道所有可能的主机名字符是什么(以及可能需要的任何其他模式 - 主机名是否需要以字母开头？)。

主机名的示例包括 localhost 或 google.com。

Answer 1

看看这个 wiki ，特别是有效主机名的限制

部分

Hostnames are composed of series of labels concatenated with dots, as are all domain names. For example, "en.wikipedia.org" is a hostname. Each label must be between 1 and 63 characters long, and the entire hostname (including the delimiting dots but not a trailing dot) has a maximum of 253 ASCII characters.

The Internet standards (Requests for Comments) for protocols mandate that component hostname labels may contain only the ASCII letters 'a' through 'z' (in a case-insensitive manner), the digits '0' through '9', and the hyphen ('-'). The original specification of hostnames in RFC 952, mandated that labels could not start with a digit or with a hyphen, and must not end with a hyphen. However, a subsequent specification (RFC 1123) permitted hostname labels to start with digits. No other symbols, punctuation characters, or white space are permitted.