CODEWITHSUNDEEP
c#.net.net-corecsproj
sakra
sakra

Reputation: 65891

csproj copy files depending on operating system

I am using .NET Core to build a cross platform class library. Depending on the operating system that the C# .NET Core project is built for using a .csproj file, I need to copy a native library to the project's output directory. E.g., for OS X I want to copy a .dylib file, for Windows I want to copy a .DLL file, for Linux I want to copy a .so file.

How can I do this with a Condition clause in a .csproj ItemGroup?

  <ItemGroup>
    <Content Include="libNative.dylib" Condition=" '$(Configuration)|$(Platform)' == 'Debug|OSX' ">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </Content>
  </ItemGroup>

$(Platform) does not seem to work. Is there a different variable I can use?

Upvotes: 35

Views: 15364

Answers (4)

iinuwa
iinuwa

Reputation: 637

As a follow-up to @tzachs accepted answer, since msbuild 15.3 (basically Visual Studio 2017+ or .NET Core 2+) you can shorten this to use the [MSBuild]::IsOSPlatform() method. (Documentation on this page.)

It accepts values of the OSPlatform struct, e.g. Windows, Linux, OSX, FreeBSD.

<ItemGroup>
    <Content Include="libNative.dll" Condition="$([MSBuild]::IsOSPlatform('Windows'))">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </Content>
    <Content Include="libNative.so" Condition="$([MSBuild]::IsOSPlatform('Linux'))">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </Content>
    <Content Include="libNative.dylib" Condition="$([MSBuild]::IsOSPlatform('OSX'))">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </Content>
</ItemGroup>

Upvotes: 21

kogoel
kogoel

Reputation: 1

Wanted to create cross platform for my Nuget Package as well. Tried below code in .csproj.

<Content Include="libNative.win" Condition=" '$(OS)' == 'Windows_NT' ">
<Content Include="libNative.dylib" Condition=" '$(OS)' != 'Windows_NT' ">

So created .nupkg.

When referred the same .nupkg, on linux as the $(OS) was already set to Windows_NT, added the libNative.win and not libNative.dylib(which was expected).

So this $(OS) is set when nuget was created and not when it was added. For more details: you can use $(OS) or $(Platform) in the <Description> and see how the value is set.

Upvotes: 0

Alen.Toma
Alen.Toma

Reputation: 4870

I did have a problem like this and ended up saving the dll in a resource and lodaing the dll for X86 or X64, when the library first initilized. It was the cleanst way for me.

Alternative when you include the dll in nuget you have also to make sure the same dll get recoped when the som one remove/clean the bin mapp.

So you have to add the file to nuger and also create a targets on build file to recopy the dll on build

Here is what i did.

internal class EmbeddedDllClass
{
    public static void LoadAllDll()
    {
        Assembly assem = Assembly.GetExecutingAssembly();
        if (IntPtr.Size == 8)
        {
            var path = Path.Combine(string.Join("\\", assem.Location.Split('\\').Reverse().Skip(1).Reverse()), "x64");

            if (!Directory.Exists(path))
                Directory.CreateDirectory(path);

            path = Path.Combine(path, "SQLite.Interop.dll");

            if (!File.Exists(path))
                File.WriteAllBytes(path, Properties.Resources.SQLite_Interop_64);
        }
        else if (IntPtr.Size == 4)
        {
            var path = Path.Combine(string.Join("\\", assem.Location.Split('\\').Reverse().Skip(1).Reverse()), "x86");

            if (!Directory.Exists(path))
                Directory.CreateDirectory(path);

            path = Path.Combine(path, "SQLite.Interop.dll");

            if (!File.Exists(path))
                File.WriteAllBytes(path, Properties.Resources.SQLite_Interop_86);

        }
    }
}

And then just call it

EmbeddedDllClass.LoadAllDll();

Upvotes: 0

tzachs
tzachs

Reputation: 5019

For differentiating between Windows & Mac/Linux you can use the $(os) property: this gives you Windows_NT for Windows and UNIX for Mac/Linux.

For differentiating between Mac & Linux, at least on recent versions of MSBuild, you can use RuntimeInformation.IsOSPlatform.

So, combined, your csproj can have something like this:

<ItemGroup>
    <Content Include="libNative.dll" Condition=" '$(OS)' == 'Windows_NT' ">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </Content>
    <Content Include="libNative.so" Condition=" '$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Linux)))' ">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </Content>
    <Content Include="libNative.dylib" Condition=" '$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::OSX)))' ">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </Content>
</ItemGroup>

To the best of my knowledge, this should work in all recent versions of .Net Core, Mono and .Net Framework.

In older versions, you'd need to resort to evil trickery for differentiating between Mac & Linux:

For Linux -> Condition=" '$(OS)' == 'Unix' and ! $([System.IO.File]::Exists('/usr/lib/libc.dylib')) "

For Mac -> Condition=" '$(OS)' == 'Unix' and $([System.IO.File]::Exists('/usr/lib/libc.dylib')) "

Sources:

Upvotes: 49

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