How do I find CSPROJ files based on the .NET framework they may or may NOT target

Question

I want to find all .csproj files that are not targeting a specific version of the .NET Framework. Here is the regular expression I'm starting with:

(<TargetFrameworkVersion>)(v4\.5\.1)(</TargetFrameworkVersion>)

This successfully identifies all files that are targeting .NET v4.5.1. For example, it will find the following string:

<TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>

What changes would I need to make to my regular expression, if I want my search to match the following strings?

<TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
<TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
<TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>

Answer 1

To match the 3 specific versions in one expression try:

<TargetFrameworkVersion>v(2.0|4.5|4.5.2)</TargetFrameworkVersion>

However, in answer to the original question, ie "...not targeting a specific version...", if you wanted to list all the versions not targeting 4.5.1 you could use:

<TargetFrameworkVersion>(?!v4.5.1).*?</TargetFrameworkVersion>

If you just wanted to list the framework version for all files you could use this:

<TargetFrameworkVersion>v.*?</TargetFrameworkVersion>

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Note: Strictly speaking I should've escaped the period in the version numbers since unescaped they'll actually match any character but this can make the regex hard to read and since the version numbers are only single digit it shouldn't be a problem.

Comments

Perfect: (?!v4.5.1).*? is exactly what I was looking for.  Thank you so much!