Regex match optional set of characters not working

Question

I'm trying to capture the username from these lines:

title="user1 is online now"><b><font color="#2568BA"><b>user1</b></font></b></a>
title="user2 is online now"><b>user2</b></a>

With this as the pattern:

title=".{1,16} is \w{5,8}? now"><b>(?:<font color="#\w{6}">)<b>(?<text>.+?)</b>(?:</font>)</b></a>?

But it's only capturing user1. The "font color" tag needs to be ignored, sometimes it's there sometimes it's not.

I'm struggling with this for hours now, what am I missing?

Answer 1

The following might work.

• Assume that username follows title=" and is followed by is on(or off)line
• capture that instance into capturing group 1
• use a back reference to find the last instance of username in the line
• capture that into named capturing group UserName

---

title="(\S+)(?= is (?:on|off)line).*(?<UserName>\k<1>)

If you wanted to, you could also capture the on or off line status.

Answer 2

对于这些示例，这应该起作用：

title="\S+\sis\s(?:on|off)line\snow">(?:<b><font[^>]+>)?<b>(.*?)</b>

Answer 3

您可以使用以下正则表达式：

<[^>]*>(user\d+)<[^>]*>