Matching version number parts with regular expressions

Question

I'm trying to match the parts of a version number (Major.Minor.Build.Revision) with C# regular expressions. However, I'm pretty new to writing Regex and even using Expresso is proving to be a little difficult. Right now, I have this:

(?<Major>\d*)\.(?<Minor>\d*)\.(?<Build>\d*)\.(?<Revision>\d*)

This works, but requires that every part of the version number exists. What I would like to do is also match versions like:

2.13

In this case, the Build and Revision groups need to return null values. Feel free to suggest a better method if I'm going about this all wrong.

Answer 1

(?<Major>\d*)\.(?<Minor>\d*)(\.(?<Build>\d*)(\.(?<Revision>\d*))?)?

Makes the third and fourth parts optional.

Answer 2

I know this isn't a regex, but System.Version does all the work for you.

Answer 3

Tested in VBScript, this pattern:

^(\d+)(\.\d+)?(\.\d+)?(\.\d+)?$

Will validate all the following True:

• 23
• 23.1
• 23.1.1
• 23.1.1.1

And the following all False:

• 23.11.11.33.11
• 23.43 2.1
• 44.11.2 3
• 3q.4.2.1
• 3.4.
• 4.3.21a

Answer 4

If you don't want to use Regex you could try:

System.Diagnostics.FileVersionInfo fvi = System.Diagnostics.FileVersionInfo.GetVersionInfo(<string filePath>);

int major = fvi.FileMajorPart;
int minor = fvi.FileMinorPart;
int build = fvi.FileBuildPart;

Answer 5

Above answer not working properly

(?<Major>\d*)\.(?<Minor>\d*)(\.(?<Build>\d*)(\.(?<Revision>\d*))?)?

try this one,

  var regularExpression = @"^(\d+\.)?(\d+\.)?(\d+\.)?(\*|\d+)$";
                var regex = Regex.IsMatch("1.0.0.0", regularExpression, RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
                Console.WriteLine(regex);

Answer 6

Try something like this:

(?<Major>\d*)\.?(?<Minor>\d*)?\.?(?<Build>\d*)?\.?(?<Revision>\d*)?

I simply added some "zero or one" quantifiers to the capture groups and also to the dots just in case they are not there.