Combine results from multiple xpaths in xmlint

Question

I'd like to return the results from multiple --xpath phrases. I have tried

xmllint --xpath '//ItemGroup/Content/@Include' --xpath '//ItemGroup/None/@Include' --xpath '//Compile/@Include' -

This returns only the last xpath

I have tried the same thing using concat() however that returns only one match from each xpath:

xmllint  --xpath "concat(concat(//ItemGroup/None/@Include,' ', //ItemGroup/Content/@Include), ' ', //ItemGroup/Compile/@Include)" -

Answer 1

You should you the union operator | like this:

xmllint --xpath '//ItemGroup/Content/@Include | //ItemGroup/None/@Include | //Compile/@Include' input.xml

With a sample XML like

<?xml version="1.0" encoding="UTF-8"?>
<class>
    <ItemGroup>
        <Content Include="First Item"> aaa </Content>
        <None Include="Third Item"> bbb </None>
        <Content Include="Second Item"> aaa </Content>
    </ItemGroup>
    <parent>
        <Compile Include="Compiling is great"> aaa </Compile>
        <sub2> bbb </sub2>
    </parent>
</class>

the output is:

Include="First Item" Include="Third Item" Include="Second Item" Include="Compiling is great"

This does work with XPath-1.0.