Thursday, October 22, 2020

Fedora 32 : Can be better? part 016.

Today I tested the Unity 3D version 2020 on Linux Fedora 32.
Maybe it would be better to integrate Unity 3D or Unity Hub in Fedora repo just like other useful software like Blender 3D, GIMP.
It will improve the user experience and attract new users and developers for this distro.
I download the AppImage from Unity website and I run with these commands:
[mythcat@desk Downloads]$ chmod a+x UnityHub.AppImage 
[mythcat@desk Downloads]$ ./UnityHub.AppImage 
r: 0
License accepted

Sunday, October 18, 2020

Fedora 32 : About positive and negative lookahead with Bash commands.

Today I will talk about something more complex in Linux commands called: positive and negative lookahead.
This solution can be found in several programming languages including Bash
The lookahead process is part of regular expressions.
The lookahead process looks ahead in the string and sees if it matches the given pattern, but then disregard it and move on.
It is very useful when we want to go through the strings.
The lookahead process can be both positive and negative depending on the purpose.
Negative lookahead is indispensable if you want to match something not followed by something else and looks like this:
The string is the question q is analyzed and if it does not match and is not followed by s returns the result.
The positive lookahead it works the same way only now it is parsed if it corresponds to s.
The positive lookahead looks like this:
Let's look at a simple example of detecting the PAE option for the processor.
We can use this command but we will find a lot of information ...
[root@desk mythcat]# cat /proc/cpuinfo
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 58
model name	: Intel(R) Celeron(R) CPU G1620 @ 2.70GHz
stepping	: 9
In some cases, the resulting information can be taken using pipe and grep but they will be increasingly fragmented.
I will use the same command cpuinfo and we will look for the pae information in the flags.
All CPU flags can be found here.
Let's prove with internal lookahead to find the pae flag.
[root@desk mythcat]# cat /proc/cpuinfo | grep -oP '(?='pae')...' 
This result gives me additional information, namely that there are two cores.
Do you have a question?

Saturday, October 17, 2020

Fedora 32 : Visual Code and C# on Fedora distro.

Today I will show you how to use Visual Code with C#.
sudo rpm --import
sudo sh -c 'echo -e "[code]\nname=Visual Studio Code\nbaseurl=
vscode\nenabled=1\ngpgcheck=1\ngpgkey=" > 
Then use dnf to check and install this editor.
#dnf check-update
#dnf install code
Use Extensions button or Ctrl+Shift+X keys to open in the left side area and intall the C# extension from Microsoft by pressing the Install button, see:

Created a folder named CSharpProjects and using the linux terminal execute the following command:
[mythcat@desk CSharpProjects]$ dotnet new mvc -au None -o aspnetapp
The template "ASP.NET Core Web App (Model-View-Controller)" was created successfully.
This template contains technologies from parties other than Microsoft, 
see for details.

Processing post-creation actions...
Running 'dotnet restore' on aspnetapp/aspnetapp.csproj...
  Restore completed in 112.76 ms for /home/mythcat/CSharpProjects/aspnetapp/aspnetapp.csproj.

Restore succeeded.

[mythcat@desk CSharpProjects]$ cd aspnetapp/
[mythcat@desk aspnetapp]$ code .
This command will open the Visual Code. At this point, in the aspnetapp folder is an ASP.NET project open in Visual Code. You can run this project with command:
[mythcat@desk aspnetapp]$ dotnet run
warn: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[35]
      No XML encryptor configured. Key {4c284989-9a5d-4ea7-89e2-a383828fd7ab} may be persisted 
      to storage in unencrypted form.
info: Microsoft.Hosting.Lifetime[0]
      Now listening on: https://localhost:5001
info: Microsoft.Hosting.Lifetime[0]
      Now listening on: http://localhost:5000
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Development
info: Microsoft.Hosting.Lifetime[0]
      Content root path: /home/mythcat/CSharpProjects/aspnetapp
You can open the https://localhost:5001/ and see the default Welcome page from ASP.NET.

Saturday, October 3, 2020

Fedora 32 : Create games with Phaser Editor 2D.

Today I install Phaser Editor 2D on Fedora 32, you can download it from the official website. I create an account and I download the archive for Linux. After unarchive I used very simple:
[mythcat@desk ~]$ cd PhaserEditor2D/
[mythcat@desk PhaserEditor2D]$ ls
editor  PhaserEditor2D  README.TXT  templates
[mythcat@desk PhaserEditor2D]$ ./PhaserEditor2D 
Phaser Editor 2D - v3.7.1

=> Running in Free mode (only 70 files per project allowed)
=> Purchase a license:

2020/10/03 16:17:51 Loading workspace at /home/mythcat/PhaserEditor2D_Projects
2020/10/03 16:17:51 Listening at

Play IDE online :
Documentation   :
File bugs/ideas :
Keep in contact :

=> Open the web browser at

2020/10/03 16:17:52 No updates available.
Phaser Editor 2D is a commercial IDE to develop video-games. It is delivered as an offline product and users can run it for free (with certain limitations) or can purchase a license key to unlock all features. Phaser Editor 2D version 3, the latest, is a complete new software based on web technologies. So we created Play Phaser Editor 2D, a small service to allow Phaser Editor 2D license owners, to run the editor and create small projects in the cloud. However, in the future, we will provide a different cloud service with options for storage, collaboration, publishing, integration with other services and payment. These are the Play Phaser Editor 2D available plans: Free Plan and Premium Plan About Free Plan: Running the FREE PLAN 0B/50MB of storage is used 59 days before expiration date The Premium Plan comes with these options:
  • One Year License - 30$ Valid for one year after the purchase. Phaser Editor 2D Team email support. Write to The option to refund in the first month after the purchase.
  • Two Years License - 45$ Valid for two years after the purchase. Phaser Editor 2D Team email support. Write to The option to refund in the first month after the purchase.
  • Lifetime License - 75$ Never expires. Phaser Editor 2D Team email support. Write to The option to refund in the first month after the purchase.
  • Two Years Team License - 125$ 5 developers allowed. Valid for two years. Phaser Editor 2D Team email support. Write to The option to refund in the first month after the purchase.
This is a video tutorial from official youtube channel:

Friday, October 2, 2020

Fedora 32 : Can be better? part 015.

In the evening I can spend my time with Fedora 32.

In the last few days I studied GTK # a bit.

I thought it would be useful for Linux users and those who use the language of the FASM assembler to have an editor.

Tonight I created this simple project this simple project named fasm_editor.

The objectives of this project are:

  • creating a functional editor;
  • implementation of running and compilation requirements;
  • settings specific to the Linux operating system;

I believe that this way Fedora Linux can be improved and become better.

Wednesday, September 30, 2020

Fedora 32 : Can be better? part 014.

The GTK documentation for C # is not very up to date, I tried to use a button to change a label and I failed first time. The Fedora team could improve this to develop the development side. Here's what I've managed to do so far with GTK.

I fixed the source code with this, but I would have preferred a better method:

my_Button.Clicked += delegate {
my_Label.Text = "Use delegate!";

Mono is a free and open source implementation of the .NET Framework.

The most popular build tool for Mono is NAnt.

NUnit is very useful for test driven development.

[root@desk mythcat]# dnf install mono-devel
Last metadata expiration check: 0:15:26 ago on Wed 30 Sep 2020 09:04:30 PM EEST.
Package mono-devel-6.6.0-8.fc32.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
[root@desk mythcat]# dnf install nant
  log4net-2.0.8-10.fc32.x86_64            nant-1:0.92-25.fc32.x86_64           

[root@desk mythcat]# dnf install nunit nunit-gui
Last metadata expiration check: 0:02:09 ago on Wed 30 Sep 2020 09:27:18 PM EEST.
No match for argument: nunit-gui
Error: Unable to find a match: nunit-gui

Installing MonoDevelop:

[root@desk mythcat]# dnf install monodevelop


Install the .NET Core. This is a general-purpose, modular, cross-platform and open-source development Platform.

[root@desk mythcat]# dnf copr enable @dotnet-sig/dotnet
Enabling a Copr repository. Please note that this repository is not part
of the main distribution, and quality may vary.
Do you really want to enable [y/N]: y
Repository successfully enabled.
[root@desk mythcat]# dnf install dotnet
Copr repo for dotnet owned by @dotnet-sig             5.4 kB/s | 3.3 kB     00:00    
Package dotnet-3.1.108-1.fc32.x86_64 is already installed.
Dependencies resolved.
Nothing to do.

Let's start with a GTK project using the MonoDevelop I.D.E.

[mythcat@desk ProjectsCSharp]$ monodevelop 
I use a new solution from .NET with GTK# 2.0 Project template. The default source code is this:
using System;
using Gtk;

namespace MonoDevelopGTK_001
	class MainClass
		public static void Main (string[] args)
			Application.Init ();
			MainWindow win = new MainWindow ();
			win.Show ();
			Application.Run ();
The result is an simple window form. For a complex form with entry ,label and one button, you can see the next example:
using System;
using Gtk;

namespace MonoDevelopGTK_001
	class MainClass
		public static void Main (string[] args)
			// define here Entry and Button 
			Entry name;
			Button my_Button;

			Application.Init ();
			MainWindow win = new MainWindow ();
			// change the size of window
			win.SetDefaultSize (640, 480);
			// this will close application
			win.DeleteEvent += new DeleteEventHandler (Window_Delete);

			// use of VBox or HBox
			VBox global_vbox = new VBox();
			name = new Entry();
			global_vbox.PackStart(name, false, false, 0);

			VBox label_vbox = new VBox();
			global_vbox.Add (label_vbox);
			//Define here a label and put some text in it.
			Label my_Label = new Label();
			my_Label.Text = "Hello World!";
			label_vbox.PackStart(my_Label, false, false, 0);
			//Add the label to the form

			VBox button_vbox = new VBox();
			global_vbox.Add (button_vbox);
			my_Button = new Button("Ok!");
			my_Button.Clicked += OnButtonClicked;
			button_vbox.PackStart(my_Button, false, false, 0);
			// ShowAll is used to see all labels, buttons
			//win.Show ();
			Application.Run ();


		public static void OnButtonClicked (object obj, EventArgs args)
			//Label my_Label = obj as Gtk.Label;
			Console.WriteLine ("Button Clicked !");


		static void Window_Delete (object obj, DeleteEventArgs args)
			Application.Quit ();
			args.RetVal = true;

Tuesday, September 29, 2020

Fedora 32 : Can be better? part 013.

I would say that I always have a problem with accessing the knowledge base related to errors, errors and configurations in Linux and Fedora distro.

I think it would be very necessary to have as up-to-date documentation as possible in the Fedora distribution system and possibly a database based on questions and answers.

That makes me think of the pilots' manuals ... where all the possible problems are listed.

It would be useful for anyone and especially saves users' memory.

In the age of artificial intelligence, a flow chart for each possible problem generated by Xorg, Network, services that indicate the areas of interaction and possibly the basic checks that a user should make, possible settings depending on the problem or the desired change would be a fantastic map for both a beginner and an advanced user.

After doing some SELinux configurations, my browser did not want to access the internet.

Until the deactivation, the number of SELinux alerts increased dramatically.

The written SELinux policies were not exactly correct.

Obviously I tried to fix the problem by disabling SELinux.

The ping utility sent and received packets to the internet, my browser does not connect to it.

Sometimes a symbolic link or incorrect setting can block your internet access.

I think the problem was generated when disabling SELinux by restarting and shutting down a useful service.

ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
Although attention was paid to the possibility of incorrect SELinux settings, a simple check and a restart of the systemd-resolved.service service solved the problem.
[root@desk mythcat]# systemctl status systemd-resolved.service 
● systemd-resolved.service - Network Name Resolution
     Loaded: loaded (/usr/lib/systemd/system/systemd-resolved.service; disabled
     Active: inactive (dead)
       Docs: man:systemd-resolved.service(8)
[root@desk mythcat]# systemctl start systemd-resolved.service 
[root@desk mythcat]# systemctl status systemd-resolved.service
● systemd-resolved.service - Network Name Resolution
     Loaded: loaded (/usr/lib/systemd/system/systemd-resolved.service; disabled
     Active: active (running) since Tue 2020-09-29 22:25:32 EEST; 8s ago

Now I've fixed it.