Find version number with Regex in .NET

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My english is a little bit unpolished, so please be patient with my grammatics.

I have the following regex's to find a version number in a string, for example this user agent: "Opera/9.80 (Windows NT 6.0) Presto/2.12.388 Version/12.14",

1. (\d+\.)?(\d+\.)?(\d+\.)?(\*|\d+)
2. (\*|(\d+(\.(\d+(\.(\d+|\*))?|\*))?))

which I believe means (and correct me where I'm wrong):
1: the first 3 groups means "up to 3 digit(s)-dot", but in the fourth, what does the "\*" do?
2: again, what does the "\*" do?

Posted 2-Nov-13 1:31am

LGSon2

Updated 3-Nov-13 21:05pm

v4

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OriginalGriff · Accepted Answer · 2013-11-02T01:55:00

Solution 1

If you aren't sure, then the best thing to do is to get a copy of Expresso: http://www.ultrapico.com/expresso.htm[^]
It's free, and it explains, helps you create and tests Regexes - I use it all the time and really wish I'd written it. (And I wish it came in an Android version, too).

"\*"in a Regex is a literal "*" - so

(\*|\d+)

matches a single star or one-or-more digits.

Posted 2-Nov-13 1:55am

OriginalGriff

Comments

LGSon2 4-Nov-13 3:06am

Thanks for the link to expresso

OriginalGriff 4-Nov-13 3:13am

You're welcome!