如何从WHOIS结果中解析电子邮件地址

Question

Suppose I have a WHOIS lookup that returns results in the following format (simplified for this question:)

Domain name:           mydomain.ca
Administrative contact:
    Name:              John Smith
    ... other fields...
    Email:             johnsmith@gmail.com
Technical contact:
    Name:              Jane Doe
    Email:             janedoe@gmail.com
Name servers:
    ns1.mydomain.com
    ns2.mydomain.com

I want a regex that will give me the Administrative contact's email address (johnsmith@gmail.com), but NOT the Technical contact's email address. It's not important to verify the format of the email address itself.

Answer 1

I wouldn't try to use a regex for this at all. Here's what I might do:

1. Split the response into lines
2. Scan for the line that reads "Administrative contact:"
3. Scan for the next line that has "Email:"
4. Extract the second word on that line

You may need to fine-tune this procedure as necessary.

Answer 2

The regex would be:

"Administrative contact:.*?Email: *([^ \n]*)"

You need to make the '.' special character match any character at all, including a newline. Not sure how you do that in C#, but in python the matching (tested it and it works) is done like this:

match = re.search(r"Administrative contact:.*?Email: *([^ \n]*)", text, re.DOTALL)

You might also take into account that this is very inefficient for large files (having . match newlines is quite expensive), so you might take Jordan's solution into account too.

Answer 3

Well, you could just search for email strings in general, the regex for that is:

([\w-+]+(?:\.[\w-+]+)*@(?:[\w-]+\.)+[a-zA-Z]{2,7})

As mentioned before though, registrars can have very different formats on their pages, multiple email addresses, etc. which is going to make this a pain for you.