Get .Net Core Dll Version on Linux

Get .NET Core DLL version on Linux

I use exiftool:

$ exiftool /usr/lib64/dotnet/sdk/2.0.3/Microsoft/Microsoft.NET.Build.Extensions/tools/netcoreapp1.0/System.Threading.dll | grep -i version
ExifTool Version Number         : 10.55
Linker Version                  : 48.0
OS Version                      : 4.0
Image Version                   : 0.0
Subsystem Version               : 4.0
File Version Number             : 4.6.24705.1
Product Version Number          : 0.0.0.0
File Version                    : 4.6.24705.01
Product Version                 : 4.6.24705.01. Commit Hash: 4d1af962ca0fede10beb01d197367c2f90e92c97
Assembly Version                : 4.0.12.0

Originally discovered from here.

Watch out, though. It doesn't work on crossgened stuff:

$ exiftool /usr/lib64/dotnet/sdk/2.0.3/Roslyn/Microsoft.CodeAnalysis.dll
ExifTool Version Number         : 10.55
File Name                       : Microsoft.CodeAnalysis.dll
Directory                       : /usr/lib64/dotnet/sdk/2.0.3/Roslyn
File Size                       : 4.6 MB
File Modification Date/Time     : 2018:01:24 13:12:48-05:00
File Access Date/Time           : 2018:02:01 12:37:59-05:00
File Inode Change Date/Time     : 2018:01:26 09:52:23-05:00
File Permissions                : rw-r--r--
Error                           : File format error

Get dll metadata in Linux environment

Using AssemblyMetadata from Microsoft.CodeAnalysis.Common package you can read the content of a dll like Version, Module, Type, Reference, Property, and pretty much everything

var path = @"path/to/dll/file.dll";
var metadata = AssemblyMetadata.CreateFromFile(path);
var module = metadata.GetModules().First();
Console.WriteLine(module.Name);

var reader = module.GetMetadataReader();

var assemblyDef = reader.GetAssemblyDefinition();
Console.WriteLine(reader.GetString(assemblyDef.Name));
Console.WriteLine(assemblyDef.Version.ToString());

foreach (var typeDefHandle in reader.TypeDefinitions)
{
    var typeDef = reader.GetTypeDefinition(typeDefHandle);
    var fullName = (reader.GetString(typeDef.Namespace) + "::" + reader.GetString(typeDef.Name));
    Console.WriteLine(fullName);
}

Linux .NET 6 exe seeks DLL in current dir instead of its own

Turns out the correct link command was:

ln -s /home/UserName/Dev/ProgramName/bin/Debug/net6.0/ProgramName ProgramName

(confusion resulting from the order being swapped relative to Windows's symbolic link command line)

Is there a Linux equivalent module and function for LoadLibrary() from kernel32.dll that i can call from .Net Core?

A couple of thoughts.

First, yes, DllImport (P/Invoke) works on Linux (and macOS) too.

This seems a bit strange:

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate short AdcOpen([MarshalAs(UnmanagedType.LPStr)] string adcName, [MarshalAs(UnmanagedType.LPStr)] string protocol, [MarshalAs(UnmanagedType.LPStr)] string port, ref short handle, byte performSwReset);
    private AdcOpen adcOpen;

With the mapping code (LoadLibrary, GetProcAddress, FreeLibrary), this seems like you are manually doing the work that .NET itself does if you do something like this - where you let .NET do the function finding and binding:

    [DllImport("ourdevice.dll", CallingConvention = CallingConvention.Cdecl)]
    private static extern short AdcOpen([MarshalAs(UnmanagedType.LPStr)] string adcName, [MarshalAs(UnmanagedType.LPStr)] string protocol, [MarshalAs(UnmanagedType.LPStr)] string port, ref short handle, byte performSwReset);

Any reason for doing it so differently?

Because if you were to do it that way, I expect the Linux version will look like this and work pretty much the same way as it does on Windows:

    [DllImport("libourdevice.so", CallingConvention = CallingConvention.Cdecl)]
    private static extern short AdcOpen([MarshalAs(UnmanagedType.LPStr)] string adcName, [MarshalAs(UnmanagedType.LPStr)] string protocol, [MarshalAs(UnmanagedType.LPStr)] string port, ref short handle, byte performSwReset);

Assuming you are using the same calling convention and argument marshalling.
The only difference is the name change from "ourdevice.dll" to "libdevice.so". You will also need to place libdevice.so somewhere where it can be found; next to the application executable should work.

If you still want to do it manually via the LoadLibrary/GetProcAddress/FreeLibrary approach, you can use the roughly-equivalent methods on Linux:

• dlopen (similar to LoadLibrary)
• dlsym (similar to GetProcAddress)
• dlclose (similar to FreeLibrary)

See https://stackoverflow.com/a/13492645/3561275 for examples and sample code on how to use these methods.

How to check the version of an assembly (dll)?

You can use Reflector, ILDASM or ILSpy to get the assembly version.

You usually can find ILDASM in C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1A\bin\NETFX 4.5.1 Tools\ildasm.exe (where v8.1A is the version of the Windows SDK installed).

ILDASM:

Reflector:

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