正则表达式从 URL 中提取子域? [英] Regex to extract subdomain from URL?

问题描述

我有一堆这样的域名:

http://subdomain.example.com(example.com 始终是 example.com，但子域因人而异).

http://subdomain.example.com (example.com is always example.com, but the subdomain varies).

我需要子域".

有耐心学习正则表达式的好心人可以帮助我吗?

Could some kind person who had the patience to learn regex help me out?

推荐答案

/(http:\/\/)?(([^.]+)\.)?domain\.com/

如果提供了子域"，则 $3(或 \3)将包含子域".

Then $3 (or \3) will contain "subdomain" if one was supplied.

如果您想在第一组中拥有子域，并且您的正则表达式引擎支持非捕获组(害羞组)，使用这是 palindrom 建议的:

If you want to have the subdomain in the first group, and your regex engine supports non-capturing groups (shy groups), use this as suggested by palindrom:

/(?:http:\/\/)?(?:([^.]+)\.)?domain\.com/

这篇关于正则表达式从 URL 中提取子域?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！