.NET Core console app on MacOS

.NET Core console app on MacOS


In this article we create step by step a simple .NET Core console application on MacOS. First, the .NET Core SDK must be installed from https://www.microsoft.com/net/learn/get-started/macos. The .NET Core SDK includes the latest release of the .NET Core framework, runtime and compiler tools.

Step 1. Create a new console app

The dotnet application is the general driver for running .NET command-line commands. We use it throughtout the article to create, build and run our project. Its first argument indicates the .NET command one wants to execute. In the following we initialize a new console application project with the name pdfinfo by executing the dotnet newconsole -o pdfinfo command. It creates a new directory in the current working directory called pdfinfo and initializes it with the necessary files from the console project template. After the initialization, it also performs a dotnet restore step to ensure that all the NuGet dependencies are installed and ready to use.

$ dotnet new console -o pdfinfo

Getting ready...
The template "Console Application" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on pdfinfo/pdfinfo.csproj...
  Restoring packages for /Users/frank/gitwork/pdfinfo/pdfinfo.csproj...
  Generating MSBuild file /Users/frank/gitwork/pdfinfo/obj/pdfinfo.csproj.nuget.g.props.
  Generating MSBuild file /Users/frank/gitwork/pdfinfo/obj/pdfinfo.csproj.nuget.g.targets.
  Restore completed in 629.41 ms for /Users/frank/gitwork/pdfinfo/pdfinfo.csproj.

Step 2. Run the default app

The default console application project template is a simple application that prints Hello World! to the console. To verify that the previous step was performed properly, type dotnet run. You should see the following output:

$ dotnet run
Hello World!

Step 3. Add a reference to PDFKit.NET 5.0

You can add new NuGet references to the project by the dotnet add command. Let’s add PDFKit5 to the project now from the NuGet repository:

$ dotnet add package TallComponents.PDFKit5

Step 4. Open PDF and display page count

In the pdfkit directory there is one C# source code file, generated by the dotnet new command, called Program.cs. Let’s replace it to create a simple application that displays the number of pages of a given PDF. The application will simply create a FileStream instance and uses it to instantiate a PDFKit Document class. The Document class has a Pages property that returns a collecion of pages, thus can be used to count them. The source code is as simple as follows:

using System;
using System.IO;

using TallComponents.PDF;

namespace pdfinfo
  class Program
    static void Main(string[] args)
      using (FileStream file = new FileStream("DeveloperGuide.pdf", FileMode.Open, FileAccess.Read))
        Document pdf = new Document(file);
        Console.WriteLine($"pdf has {pdf.Pages.Count} pages");

Finally, running the application again, depeding of course on the actual PDF you used, you sould see something like this:

$ dotnet run
pdf has 49 pages