How can I group multiple e-mail addresses and user names using a regular expression

Question

I have the following text that I am trying to parse:

"[email protected]" <[email protected]>, "Jane Doe" <jane.doe@ addyB.org>,
"[email protected]" <[email protected]>

I am using the following code to try and split up the string:

Dim groups As GroupCollection
Dim matches As MatchCollection
Dim regexp1 As New Regex("""(.*)"" <(.*)>")
matches = regexp1 .Matches(toNode.InnerText)
For Each match As Match In matches
    groups = match.Groups
    message.CompanyName = groups(1).Value
    message.CompanyEmail = groups(2).Value
Next

But this regular expression is greedy and is grabbing the entire string up to the last quote after "[email protected]". I'm having a hard time putting together an expression that will group this string into the two groups I'm looking for: Name (in the quotes) and E-Mail (in the angle brackets). Does anybody have any advice or suggestions for altering the regexp to get what I need?

Answer 1

How about """([^""]*)"" <([^>]*)>" for the regex? I.e. make explicit that the matched part won't include a quote/closing paren. You may also want to use a more restrictive character-range instead.

Answer 2

You need to specify that you want the minimal matched expression. You can also replace (.*) pattern by more precise ones: For example you could exclude the comma and the space... Usually it's better to avoid using .* in a regular expression, because it reduces performance !

For example for the email, you can use a pattern like [\w-]+@([\w-]+.)+[\w-]+ or a more complex one.
You can find some good patterns on : http://regexlib.com/

Answer 3

Not sure what regexp engine ASP.net is running but try the non-greedy variant by adding a ? in the regex.

Example regex

""(.*?)"" <(.*?)>

Answer 4

Rather than rolling your own regular expression, I would do this:

string[] addresses = toNode.InnerText.Split(",");
foreach(string textAddress in addresses)
{
    textAddress = address.Trim();
    MailAddress address = new MailAddress(textAddress);
    message.CompanyName = address.DisplayName;
    message.CompanyEmail = address.Address;
}

While your regular expression may work for the few test cases that you have shown. Using the MailAddress class will probably be much more reliable in the long run.