Compiling Hello World on .NET Core 5.0

I followed the instructions for the .NET Core 5.0 “Hello World” demo code available here^[1]. What I have added in this version of the tutorial are the command line arguments for a single executable in Linux.

In brief, the Linux version compiles into two files and you only need one, the hello executable, to run. Windows dotnet compiles with other garbage still.

I think I would like to see this as the compiler option for a single executable on all platforms:

rem Example of prefered code for compiling to a single executable with all libraries and runtime together:
dotnet --compile
rem This is not how it works though!
rem You could add debug...
dotnet --compile --debug
rem or... dotnet publish <profile>
dotnet publish release
rem or...
dotnet -p=release
rem = myfk.exe

I’m a bit gaslit having found there is WPF and not UWP in Core 5.0.

Steps:

1. Install dotnet

On Fedora 34 just run this:

sudo dnf install dotnet

For Windows there is an installer on the original tutorial^[2].

2. Test the Install

dotnet --info

3. Create a New Console App

Note that the Program.cs will be created automatically for you including the code.

dotnet new console -o hello
cd hello

The project file looks like this:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net5.0</TargetFramework>
  </PropertyGroup>

</Project>

The code in Program.cs looks like this:

using System;

namespace hello
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
        }
    }
}

4. Compile the Project

LINUX

dotnet publish -c Release -r linux-x64 -p:PublishSingleFile=true --self-contained true
cd bin/Release/net5.0/linux-x64/publish

The compiler output (linux): (note: it still runs without the .pdb)

 60M hello
9.4K hello.pdb

Run the program (Linux) – I tested this on a VM with Fedora 34 and no ‘dotnet’ installed. Yes the output is a little big at 60M but writing a larger program would probably not add much overhead to that.

./hello

Result:

Hello World!

Ya!

WINDOWS

Then I’ve run the compiler on Windows:

dotnet publish -c Release -r win-x64 -p:PublishSingleFile=true --self-contained true

The compiled files (windows): (multiple files? :|) Maybe it can go in a self extracting zip?

.\hello\bin\release\net5.0\win-x64\publish

   748,936 clrcompression.dll
 1,274,248 clrjit.dll
 5,140,360 coreclr.dll
53,113,128 hello.exe
     9,584 hello.pdb
 1,056,632 mscordaccore.dll

7 File(s)     61,342,888 bytes

References

[1, .NET Tutorial | Hello World in 10 minutes, https://dotnet.microsoft.com/learn/dotnet/hello-world-tutorial/intro, accessed 9th Jun 2021]
[2, .NET Tutorial | Hello World in 10 minutes, Install, https://dotnet.microsoft.com/learn/dotnet/hello-world-tutorial/install, accessed 9th Jun 2021]