Fedora 28 : Add the Fedora logo to the Google document.

I've been able to progress with Google Apps Script.
The latest tutorial with number 008.
This tutorial is about adding a logo and creating an add-on to a document in google drive.
See the full tutorial here, and result of this addon:

Fedora 28 : Start a service daemon with Python.

In this tutorial I will starting one service using systemctl , python and systemd. First, you need to create a file named testpython.service .

[mythcat@desk system]# cd /etc/systemd/system/
[root@desk system]# vim testpython.service

This file is a configuration file for this service.

[Unit]
Description=Python Service
After=multi-user.target
[Service]
Type=simple
ExecStart=/usr/bin/python /home/mythcat/test_service.py
[Install]
WantedBy=multi-user.target

Create the python file for this service. I named test_service.py .

[root@desk system]# exit
exit
[mythcat@desk system]$ cd ~
[mythcat@desk ~]$ vim test_service.py

#!/usr/bin/env python

import logging
import time

logging.basicConfig(level="INFO")

while True:
    logging.info("Hi")
    time.sleep(3)

Change permissions file for this python file and testpython.service, see:

[mythcat@desk ~]$ chmod 764 test_service.py

Because you run this service with systemd then selinux will send you error, fix that:

[mythcat@desk ~]$ chcon -t bin_t ~/test_service.py

Reload all services and start your service with this commands:

[root@desk system]# systemctl daemon-reload
[root@desk system]# systemctl start  testpython.service
[root@desk system]# systemctl status  testpython.service
● testpython.service - Python Service
   Loaded: loaded (/etc/systemd/system/testpython.service; enabled; vendor>
   Active: active (running) since Sat 2018-09-22 21:36:23 EEST; 5s ago
 Main PID: 7213 (python)
    Tasks: 1 (limit: 2102)
   Memory: 5.7M
   CGroup: /system.slice/testpython.service
           └─7213 /usr/bin/python /home/mythcat/test_service.py

Sep 22 21:36:23 desk systemd[1]: Started Python Service.
Sep 22 21:36:24 desk python[7213]: INFO:root:Hi
Sep 22 21:36:27 desk python[7213]: INFO:root:Hi

You can use the journalctl command to see the output of this service:

[root@desk system]# journalctl -u testpython.service 
-- Logs begin at Sat 2018-09-22 20:40:06 EEST, end at Sat 2018-09-22 21:31:07 EEST. --
Sep 22 20:40:06 desk python[6232]: INFO:root:Hi
Sep 22 20:40:09 desk python[6232]: INFO:root:Hi
Sep 22 20:40:12 desk python[6232]: INFO:root:Hi
Sep 22 20:40:15 desk python[6232]: INFO:root:Hi
Sep 22 20:40:18 desk python[6232]: INFO:root:Hi
Sep 22 20:40:21 desk python[6232]: INFO:root:Hi
Sep 22 20:40:24 desk python[6232]: INFO:root:Hi
Sep 22 20:40:27 desk python[6232]: INFO:root:Hi
Sep 22 20:40:30 desk python[6232]: INFO:root:Hi

Let's see the result:

Fedora 28 : Using AdonisJs web framework.

AdonisJs is a Node.js web framework with a breath of fresh air and drizzle of elegant syntax on top of it.
We prefer developer joy and stability over anything else.
I tested today this web framework named AdonisJs with Fedora 28.
The main goal was to use MySQL with MariaDB from Fedora 28 distro.
Let's start with the installation of AdonisJs on Fedora 28:

[root@desk mythcat]# npm i --global @adonisjs/cli
/usr/bin/adonis -> /usr/lib/node_modules/@adonisjs/cli/index.js
...
+ @adonisjs/cli@4.0.7
added 406 packages from 182 contributors in 33.533s

Go to the default user:

[root@desk mythcat]# exit
exit

Create the application , I named myapp:

[mythcat@desk ~]$ adonis new myapp
    _       _             _         _     
   / \   __| | ___  _ __ (_)___    | |___ 
  / _ \ / _` |/ _ \| '_ \| / __|_  | / __|
 / ___ \ (_| | (_) | | | | \__ \ |_| \__ \
/_/   \_\__,_|\___/|_| |_|_|___/\___/|___/

  [1/6] 🔬  Requirements matched [node & npm]
  [2/6] 🔦  Ensuring project directory is clean [myapp]
  [3/6] 📥  Cloned [adonisjs/adonis-fullstack-app]
  [4/6] 📦  Dependencies installed
  [5/6] 📖  Environment variables copied [.env]
  [6/6] 🔑  Key generated [adonis key:generate]

🚀   Successfully created project
👉   Get started with the following commands

Let's test the default myapp with this commands:

$ cd myapp
$ adonis serve --dev

[mythcat@desk ~]$ cd myapp
[mythcat@desk myapp]$ adonis serve --dev

 SERVER STARTED 
> Watching files for changes...

2018-09-16T09:47:46.799Z - info: serving app on http://127.0.0.1:3333

This is the result of the running myapp on 127.0.0.1:3333 web address:
Let's see the folders and files from AdonisJS:

[mythcat@desk myapp]$ ls
ace  config    node_modules  package-lock.json  README.md  server.js
app  database  package.json  public             resources  start

The configuration for web files can be seen here:

[mythcat@desk myapp]$ vim  start/routes.js 
'use strict'

/*
|--------------------------------------------------------------------------
| Routes
|--------------------------------------------------------------------------
|
| Http routes are entry points to your web application. You can create
| routes for different URL's and bind Controller actions to them.
|
| A complete guide on routing is available here.
| http://adonisjs.com/docs/4.1/routing
|
*/

/** @type {import('@adonisjs/framework/src/Route/Manager'} */
const Route = use('Route')

Route.on('/').render('welcome')
~                                                                               

This is telling Adonis that when the root of the site is loaded, render a template/view called welcome.
That welcome template can be found in /resources/views/welcome.edge.

[mythcat@desk myapp]$ cd resources/
[mythcat@desk resources]$ ll
total 0
drwxrwxr-x. 2 mythcat mythcat 26 Sep 16 12:46 views
[mythcat@desk resources]$ cd views/
[mythcat@desk views]$ ll
total 4
-rw-rw-r--. 1 mythcat mythcat 339 Sep 16 12:46 welcome.edge

Let's see the source code of this default webpage:

[mythcat@desk views]$ vim welcome.edge 
...

For example, if you change into start/routes.js from welcome to index then you need to rename the welcome.edge to index.edge .
About css files you can make changes into public/style.css :

[mythcat@desk myapp]$ cd public/
[mythcat@desk public]$ vim  style.css


@import url('https://fonts.googleapis.com/css?family=Montserrat:300');

html, body {
  height: 100%;
  width: 100%;
}

body {
  font-family: 'Montserrat', sans-serif;
  font-weight: 300;
  background-image: url("/splash.png");
  background-color: #220052;
}

* {
  margin: 0;
  padding: 0;
}
...

Using the mysql database is simple. Into Fedora 28 distro you can use mariadb, let's install it.

[mythcat@desk myapp]$ su
Password: 
[root@desk myapp]# dnf install mariadb mariadb-server
...
Complete!
[root@desk myapp]# systemctl start mariadb
[root@desk myapp]# systemctl status mariadb
● mariadb.service - MariaDB 10.2 database server
...

You need to make changes into .env file into your project folder.

[mythcat@desk myapp]$ vim .env
HOST=127.0.0.1
PORT=3333
NODE_ENV=development
APP_URL=http://${HOST}:${PORT}
CACHE_VIEWS=false
APP_KEY=xxxxxxxxxxxxxxxx
DB_CONNECTION=sqlite
DB_HOST=127.0.0.1
DB_PORT=3306
DB_USER=root
DB_PASSWORD=
DB_DATABASE=adonis
SESSION_DRIVER=cookie
HASH_DRIVER=bcrypt
~

Use this changes for mariadb:

DB_CONNECTION=mysql

Install into AdonisJs with this command:

[mythcat@desk myapp]$ adonis install mysql
  [1/1] 📦  Dependencies installed [mysql]

Use this mysql commands to create the database:

[mythcat@desk myapp]$ mysql -u root
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 18
Server version: 10.2.17-MariaDB MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> create database adonis;
Query OK, 1 row affected (0.11 sec)

MariaDB [(none)]> exit;
Bye 

Let's test migration command for files to allow you to create and delete tables.

[mythcat@desk myapp]$ adonis migration:run
migrate: 1503248427885_user.js
migrate: 1503248427886_token.js
Database migrated successfully in 4.11 s
[mythcat@desk myapp]$ adonis make:migration jobs
> Choose an action undefined
✔ create  database/migrations/1537095058367_jobs_schema.js

Now that our database and tables have been created, I can create a model for handling jobs table and associated data.
The next tasks to follow depends by your website:

• Creating a Model 
• Creating a Controller 
• User Authentication

Fedora 28 : LibreOffice remote connection.

I wrote a tutorial about the remote connection in LibreOffice, see this article.
The main problem with LibreOffice development is the changes.
Now the feature Open remote is not working.
The bug is officially recognized and represented, see the page.
They inform us, see comment 31:
John R Mead 2017-12-17 22:43:03 UTC Well, it still doesn't work with LibreOffice Version: 6.0.0.0.beta1 (x64); I'm not providing screenshots this time since it's identical in everyway to my previous attempts. At the end of all the copy/pasting between LibreOffice and my browser to get all the relevant permissions, when I finally make the attempt to connect, I get the same message: The specified device is invalid. 

Current system configuration of potentially relevant software: 

Windows 10 Professional (x64) Version 1709 (build 16299.125) 
Java 9.0.1 
Microsoft - OneDrive version 17.25.1.0 (x64) 
LibreOffice Version: 6.0.0.0.beta1 (x64)

It's a common practice to see open-source software with bugs, most bugs are already available to users to avoid problems.
Most backup bugs are authentication and changes in development.

Fedora 28 : The Revel framework with golang.

The development team has a very effective text:
A high productivity, full-stack web framework for the Go language.
They used this words:
Revel provides routing, parameter parsing, validation, session/flash, templating, caching, job running, a testing framework, and even internationalization. I tested it yesterday and today I will show you how effective it is.
This framework is very easy to install and use it with Fedora 28.
I could say this is like django framework with the temptation style.
Let's start with a simple example into a folder created by me and named gocode:

[mythcat@desk ~]$ mkdir ~/gocode
[mythcat@desk ~]$ export GOPATH=~/gocode
[mythcat@desk ~]$ echo export GOPATH=$GOPATH >> ~/.bash_profile
[mythcat@desk ~]$ cd gocode/
[mythcat@desk gocode]$ go get github.com/revel/revel
[mythcat@desk gocode]$ ls
pkg  src
[mythcat@desk gocode]$ go get github.com/revel/cmd/revel
[mythcat@desk gocode]$ ls
bin  pkg  src
[mythcat@desk gocode]$ export PATH="$PATH:$GOPATH/bin"
[mythcat@desk gocode]$ revel helpDEBUG 19:24:09  revel  server.go:27: arguments by adding nil
~
~ revel! http://revel.github.io
~
usage: revel command [arguments]

The commands are:

    new         create a skeleton Revel application
    run         run a Revel application
    build       build a Revel application (e.g. for deployment)
    package     package a Revel application (e.g. for deployment)
    clean       clean a Revel application's temp files
    test        run all tests from the command-line
    version     displays the Revel Framework and Go version

Use "revel help [command]" for more information.
[mythcat@desk gocode]$ ls
bin  pkg  src
[mythcat@desk gocode]$ revel new myapp
DEBUG 19:38:50  revel  server.go:27: RegisterServerEngine: Registered engine 
~
~ revel! http://revel.github.io
~
Your application is ready:
   /home/mythcat/gocode/src/myapp

You can run it with:
   revel run myapp
[mythcat@desk gocode]$ revel run myapp
DEBUG 19:39:15  revel  server.go:27: RegisterServerEngine: Registered engine 
~
~ revel! http://revel.github.io
~
Trying to build with myapp (0x0,0x0)
DEBUG 19:39:15  revel module.go:152: Sorted keys  section=module keys=module.static 
...

Let's see the source code - in this case the default files: app.go and Index.html .

[mythcat@desk gocode]$ cd src/myapp/app/
[mythcat@desk app]$ ls
controllers  init.go  routes  tmp  views
[mythcat@desk app]$ cd controllers/
[mythcat@desk controllers]$ ls
app.go
[mythcat@desk controllers]$ cat app.go 
package controllers

import (
    "github.com/revel/revel"
)

type App struct {
    *revel.Controller
}

func (c App) Index() revel.Result {
    return c.Render()
}

[mythcat@desk App]$ cat Index.html 

The cat command will show the source code of Index.html file.
Let's add a golang variable named greeting to app.go and Index.html files:

[mythcat@desk controllers]$ cat app.go 
package controllers

import (
    "github.com/revel/revel"
)

type App struct {
    *revel.Controller
}

func (c App) Index() revel.Result {
    greeting := "Fedora and revel framework !"
    return c.Render(greeting)
} 

This variable greeting will will be add into file Index.html with tag p after It works!
This is result of two screenshots from start install and after I change with the variable greeting.

Fedora 28 : Linux application with node.js and Electron packager.

Today I make a tutorial about how to use node.js and Electron packager to create cross-platform applications.
The tutorial show you how to create Windows, Linux and Mac OS cross-platform applications and can be found here.
This is result of running the linux application with Fedora 28:

Fedora 28 : Godot example with linux .

Today I tested a simple example with the game engine named Godot version 3.0.6.
It was created on a Windows 8.1 operating system and exported as a linux application.
I moved the two files to the Fedora 28 operating system.

[mythcat@desk Godot_test_001]$ ll
total 41752
-rw-rw-r--. 1 mythcat mythcat    41092 Aug  2 18:34 Godot_test_001.pck
-rwxrwxr-x. 1 mythcat mythcat 42707653 Aug  2 18:34 Godot_test_001.x86_64
[mythcat@desk Godot_test_001]$ ./Godot_test_001.x86_64 
OpenGL ES 3.0 Renderer: Mesa DRI Intel(R) Ivybridge Desktop 
Mono: Initializing module...
The assembly mscorlib.dll was not found or could not be loaded.
It should have been installed in the `/usr/lib/mono/4.5/mscorlib.dll' directory.

The error occurred from the mono package and I fixed it with the installation using the dnf tool.

[root@desk mythcat]# dnf install mono-core.x86_64
Last metadata expiration check: 1:22:05 ago on Thu 02 Aug 2018 05:30:05 PM EEST.
Dependencies resolved.

...
Installed:
  mono-core.x86_64 4.8.0-14.fc28                 libgdiplus.x86_64 5.6-1.fc28                     
  mono-data.x86_64 4.8.0-14.fc28                 mono-data-sqlite.x86_64 4.8.0-14.fc28            
  mono-extras.x86_64 4.8.0-14.fc28               mono-mvc.x86_64 4.8.0-14.fc28                    
  mono-wcf.x86_64 4.8.0-14.fc28                  mono-web.x86_64 4.8.0-14.fc28                    
  mono-winforms.x86_64 4.8.0-14.fc28            

Complete!

Here's the final result:

[mythcat@desk Godot_test_001]$ ./Godot_test_001.x86_64 
OpenGL ES 3.0 Renderer: Mesa DRI Intel(R) Ivybridge Desktop 
Mono: Initializing module...
Mono: Runtime initialized
Mono: INITIALIZED

Fedora 28 : Unusual arguments for the dnf command.

Today I will introduce you in this tutorial some more unusual arguments for the dnf command.

• first is check which package provides that file;

[root@desk mythcat]# dnf provides /etc/httpd/conf/httpd.conf
Last metadata expiration check: 0:23:46 ago on Wed 01 Aug 2018 09:31:44 AM EEST.
httpd-2.4.34-3.fc28.x86_64 : Apache HTTP Server
Repo        : @System
Matched from:
Filename    : /etc/httpd/conf/httpd.conf

httpd-2.4.34-3.fc28.x86_64 : Apache HTTP Server
Repo        : updates
Matched from:
Filename    : /etc/httpd/conf/httpd.conf

httpd-2.4.33-2.fc28.x86_64 : Apache HTTP Server
Repo        : fedora
Matched from:
Filename    : /etc/httpd/conf/httpd.conf

• get detailed information of a package can be viewed with the ‘info’ argument;

[root@desk mythcat]# dnf info httpd
Last metadata expiration check: 0:29:01 ago on Wed 01 Aug 2018 09:31:44 AM EEST.
Installed Packages
Name         : httpd
Version      : 2.4.34
Release      : 3.fc28
Arch         : x86_64
Size         : 4.2 M
Source       : httpd-2.4.34-3.fc28.src.rpm
Repo         : @System
From repo    : updates
Summary      : Apache HTTP Server
URL          : https://httpd.apache.org/
License      : ASL 2.0
Description  : The Apache HTTP Server is a powerful, efficient, and extensible
             : web server.

• allows us to see what has happened to our Linux system over time, and even undo, redo, or roll back a transaction;

[root@desk mythcat]# dnf history
ID     | Command line             | Date and time    | Action(s)      | Altered
-------------------------------------------------------------------------------
   178 | upgrade                  | 2018-08-01 09:33 | Update         |   27   
   177 | upgrade                  | 2018-07-31 12:54 | Update         |   11   
   176 | upgrade                  | 2018-07-30 20:43 | Update         |    1

• take actions will be quicker with the ‘makecache’ argument

[root@desk mythcat]# time dnf makecache
Last metadata expiration check: 0:34:10 ago on Wed 01 Aug 2018 09:31:44 AM EEST.
Metadata cache created.

real    0m4.529s
user    0m1.420s
sys    0m0.229s

• list all packages that are currently installed on your Linux system;

[root@desk mythcat]# dnf list installed
Installed Packages
CharLS.x86_64                          1.0-16.fc28              @System         
Field3D.x86_64                         1.7.2-10.fc28            @System         
GConf2.x86_64                          3.2.6-20.fc28            @updates-testing
GeoIP.x86_64                           1.6.12-3.fc28            @fedora         
GeoIP-GeoLite-data.noarch              2018.06-1.fc28           @updates        
ImageMagick.x86_64                     1:6.9.9.38-1.fc28        @updates-testing
ImageMagick-c++.x86_64                 1:6.9.9.38-1.fc28        @updates-testing
ImageMagick-libs.x86_64                1:6.9.9.38-1.fc28        @updates-testing
LibRaw.x86_64                          0.18.13-1.fc28           @updates        
ModemManager.x86_64                    1.6.12-3.fc28            @fedora 

Fedora 28 : Using the python module sh .

Today I test another python module named sh with python version 3.6.5 and Fedora 28.
This python module named sh is a full-fledged subprocess replacement for Python 2.6 - 3.5, PyPy and PyPy3 that allows you to call any program as if it were a function.
You can read bout this python module here.
I used dnf tool to search and install the pip tool :

[root@desk mythcat]# dnf search python3
Last metadata expiration check: 1:06:29 ago on Mon 25 Jun 2018 09:35:04 AM EEST.
======================== Name Exactly Matched: python3 =========================
...
python3.x86_64 : Interpreter of the Python programming language

Next step is the install of python programming language:

[root@desk mythcat]# dnf install python3.x86_64 
Last metadata expiration check: 1:09:12 ago on Mon 25 Jun 2018 09:35:04 AM EEST.
Package python3-3.6.5-1.fc28.x86_64 is already installed, skipping.
Dependencies resolved.
Nothing to do.
Complete!
...

I search the pip tool and then I install it:

[root@desk mythcat]# dnf search python3-pip
Last metadata expiration check: 1:15:18 ago on Mon 25 Jun 2018 09:35:04 AM EEST.
====================== Name Exactly Matched: python3-pip ======================
python3-pip.noarch : A tool for installing and managing Python3 packages
...
[root@desk mythcat]# dnf install python3-pip.noarch 
Last metadata expiration check: 1:16:31 ago on Mon 25 Jun 2018 09:35:04 AM EEST.
Package python3-pip-9.0.3-2.fc28.noarch is already installed, skipping.
Dependencies resolved.
Nothing to do.
Complete!
...

The install of this python module into user mode:

[root@desk mythcat]# exit 
exit
...
[mythcat@desk ~]$ pip3.6 install --user sh
Requirement already satisfied: sh in /usr/lib/python3.6/site-packages

See next examples and tests I used :

[mythcat@desk ~]$ python3.6
Python 3.6.5 (default, Mar 29 2018, 18:20:46) 
[GCC 8.0.1 20180317 (Red Hat 8.0.1-0.19)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sh
>>> from sh import *
Traceback (most recent call last):
  File "", line 1, in 
  File "", line 1017, in _handle_fromlist
  File "/usr/lib/python3.6/site-packages/sh.py", line 3349, in __getattr__
    return self.__env[name]
  File "/usr/lib/python3.6/site-packages/sh.py", line 3187, in __getitem__
    Please import sh or import programs individually.")
RuntimeError: Cannot import * from sh. Please import sh or import programs individually.
...
>>> print(sh.ifconfig)
/usr/sbin/ifconfig
>>> print(sh.ifconfig())
...
>>> print(sh.ls())
...
>>> print(sh.ls("-l"))
...
>>> print(sh.uptime())
 11:25:03 up  1:52,  1 user,  load average: 1.10, 1.04, 1.40
...

Fedora 28 : Starting develop with Flutter .

Today I started with another programming language Dart and Flutter.
The development team tell us about Flutter:
Flutter is Google's mobile UI framework for crafting high-quality native interfaces on iOS and Android in record time. Flutter works with existing code, is used by developers and organizations around the world, and is free and open source.
You can read more about this on official webpage:
About linux setup you can read here.
You need also to download the Android Studio I.D.E from official webpage.
You need to install some packages using dnf tool:

[mythcat@desk ~]# dnf install libstdc++.i686
[mythcat@desk ~]#  dnf install curl

Unzip theAndroid Studio I.D.E.into android-studio folder and start it to make settings for android SDK and AVD emulated device:

[mythcat@desk ~]$ cd android-studio/
[mythcat@desk android-studio]$ ls 
bin        gradle                 jre  license      NOTICE.txt
build.txt  Install-Linux-tar.txt  lib  LICENSE.txt  plugins
[mythcat@desk android-studio]$ cd bin/
[mythcat@desk bin]$ ls
appletviewer.policy  idea.properties  printenv.py         studio.sh
format.sh            inspect.sh       restart.py          studio.vmoptions
fsnotifier           lldb             studio64.vmoptions
fsnotifier64         log.xml          studio.png
[mythcat@desk bin]$ ./studio.sh 

Select Plugins to add Dart and Flotter plugins:
You need to install Dart and Flotter plugins, use search:

Download and unarchive the Flutter from official webpage.
Next steps is to set the path for the Flutter and make settings for android licenses:

[mythcat@desk ~]$ export PATH=`pwd`/flutter/bin:$PATH
[mythcat@desk ~]$ cd flutter/
[mythcat@desk flutter]$ ls
analysis_options_repo.yaml  bin              flutter_console.bat  README.md
analysis_options.yaml       CONTRIBUTING.md  LICENSE              version
appveyor.yml                dev              packages
AUTHORS                     examples         PATENTS
[mythcat@desk flutter]$ cd bin/
[mythcat@desk bin]$ ls
cache  flutter  flutter.bat  internal
[mythcat@desk bin]$ ./flutter doctor --android-licenses
Warning: File /home/mythcat/.android/repositories.cfg could not be loaded.      
All SDK package licenses accepted.======] 100% Computing updates...             
[mythcat@desk bin]$ ./flutter doctor 
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v0.5.1, on Linux, locale en_US.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK 28.0.0)
[✓] Android Studio (version 3.1)
[!] Connected devices
    ! No devices available

! Doctor found issues in 1 category.

Use flutter command to get more help :

[mythcat@desk bin]$ ./flutter
Manage your Flutter app development.

Common commands:

  flutter create output directory=""
    Create a new Flutter project in the specified directory.

  flutter run [options]
    Run your Flutter application on an attached device or in an emulator.

Usage: flutter  [arguments]

Global options:
-h, --help            Print this usage information.
-v, --verbose         Noisy logging, including all shell commands executed.
-d, --device-id       Target device id or name (prefixes allowed).
    --version         Reports the version of this tool.
    --bug-report      Captures a bug report file to submit to the Flutter team (contains local paths, device
                      identifiers, and log snippets).

    --flutter-root    The root directory of the Flutter repository (uses $FLUTTER_ROOT if set).

Available commands:
  analyze          Analyze the project's Dart code.
  build            Flutter build commands.
  channel          List or switch flutter channels.
  clean            Delete the build/ directory.
  config           Configure Flutter settings.
  create           Create a new Flutter project.
  devices          List all connected devices.
  doctor           Show information about the installed tooling.
  drive            Runs Flutter Driver tests for the current project.
  emulators        List and launch available emulators.
  format           Format one or more dart files.
  fuchsia_reload   Hot reload on Fuchsia.
  help             Display help information for flutter.
  install          Install a Flutter app on an attached device.
  logs             Show log output for running Flutter apps.
  packages         Commands for managing Flutter packages.
  precache         Populates the Flutter tool's cache of binary artifacts.
  run              Run your Flutter app on an attached device.
  screenshot       Take a screenshot from a connected device.
  stop             Stop your Flutter app on an attached device.
  test             Run Flutter unit tests for the current project.
  trace            Start and stop tracing for a running Flutter app.
  upgrade          Upgrade your copy of Flutter.

Run "flutter help " for more information about a command. 
                                                                                                                                                                                                                                                                                                
Run "flutter help -v" for verbose help output, including less commonly used options.

Restart the Android Studio and create your first Flutter application.
You need to have all settings for your devices or emulated AVD devices to build and develop your android application.

Fedora 28 : The Powertop tool from Intel.

The Powertop is a tool provided by Intel to enable various powersaving modes in userspace, kernel and hardware.
Using this tool is possible to monitor processes and show which of them are utilizing the CPU and wake it from its Idle-States.
The tool allowing you to identify applications with particular high power demands.
The name of this tool powertop.x86_64 come from : Power consumption monitor.
Let's install and set this tool to Fedora 28 distro linux:

[root@desk mythcat]# dnf install powertop.x86_64 
Last metadata expiration check: 0:32:08 ago on Tue 19 Jun 2018 10:19:39 AM EEST.
Dependencies resolved.
================================================================================
 Package           Arch            Version               Repository        Size
================================================================================
Installing:
 powertop          x86_64          2.9-8.fc28            updates          239 k

Transaction Summary
================================================================================
Install  1 Package

Total download size: 239 k
Installed size: 650 k
Is this ok [y/N]: y
Downloading Packages:
powertop-2.9-8.fc28.x86_64.rpm                  112 kB/s | 239 kB     00:02    
--------------------------------------------------------------------------------
Total                                            71 kB/s | 239 kB     00:03     
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                        1/1 
  Installing       : powertop-2.9-8.fc28.x86_64                             1/1 
  Running scriptlet: powertop-2.9-8.fc28.x86_64                             1/1 
  Verifying        : powertop-2.9-8.fc28.x86_64                             1/1 

Installed:
  powertop.x86_64 2.9-8.fc28                                                    

Complete!

You need root privileges to run this tool :

[mythcat@desk ~]$ powertop --calibrate --debug
PowerTOP v2.9 must be run with root privileges.
exiting...

The help output of this tool :

[root@desk mythcat]# powertop --help

Usage: powertop [OPTIONS]

     --auto-tune     sets all tunable options to their GOOD setting
 -c, --calibrate     runs powertop in calibration mode
 -C, --csv[=filename]     generate a csv report
     --debug         run in "debug" mode
     --extech[=devnode]     uses an Extech Power Analyzer for measurements
 -r, --html[=filename]     generate a html report
 -i, --iteration[=iterations] number of times to run each test
 -q, --quiet         suppress stderr output
 -s, --sample[=seconds]     interval for power consumption measurement
 -t, --time[=seconds]     generate a report for 'x' seconds
 -w, --workload[=workload] file to execute for workload
 -V, --version         print version information
 -h, --help         print this help menu

For more help please refer to the 'man 8 powertop'

To run the program and enable its background services, use the commands below:

[root@desk mythcat]# systemctl start powertop.service
[root@desk mythcat]# systemctl enable powertop.service
Created symlink /etc/systemd/system/multi-user.target.wants/powertop.service → /usr/lib/systemd/system/powertop.service.

This is my output with powertop calibrate :

[root@desk mythcat]# powertop --calibrate --debug
modprobe cpufreq_stats failedLoaded 0 prior measurements
RAPL device for cpu 0
RAPL Using PowerCap Sysfs : Domain Mask d
RAPL device for cpu 0
RAPL Using PowerCap Sysfs : Domain Mask d
Devfreq not enabled
glob returned GLOB_ABORTED
Starting PowerTOP power estimate calibration 
Calibrating idle
System is not available
System is not available
Calibrating: disk usage 
Calibrating backlight
Calibrating idle
System is not available
System is not available
Calibrating: CPU usage on 1 threads
Calibrating: CPU usage on 4 threads
Calibrating: CPU wakeup power consumption
Calibrating: CPU wakeup power consumption
Calibrating: CPU wakeup power consumption
Calibrating USB devices
.... device /sys/bus/usb/devices/2-1/power/control 
.... device /sys/bus/usb/devices/usb1/power/control 
.... device /sys/bus/usb/devices/1-1.3/power/control 
.... device /sys/bus/usb/devices/1-1/power/control 
.... device /sys/bus/usb/devices/usb2/power/control 
Calibrating radio devices
Finishing PowerTOP power estimate calibration 
Parameters after calibration:


Parameter state 
----------------------------------
Value        Name
 0.50        alsa-codec-power (12)
 0.00        backlight (4)
 0.00        backlight-boost-100 (8)
 0.00        backlight-boost-40 (6)
 0.00        backlight-boost-80 (7)
 0.00        backlight-power (5)
 2.33        base power (70)
 1.56        cpu-consumption (3)
39.50        cpu-wakeups (2)
 0.00        disk-operations (73)
 0.20        disk-operations-hard (72)
 0.00        enp2s0-link-100 (21)
 0.00        enp2s0-link-1000 (22)
 0.00        enp2s0-link-high (23)
 0.00        enp2s0-packets (24)
 0.00        enp2s0-powerunsave (20)
 0.00        enp2s0-up (19)
 0.56        gpu-operations (71)
 0.00        runtime-0000:00:00.0 (34)
 0.00        runtime-0000:00:02.0 (37)
 0.00        runtime-0000:00:16.0 (44)
 0.00        runtime-0000:00:1a.0 (35)
 0.00        runtime-0000:00:1b.0 (45)
 0.00        runtime-0000:00:1c.0 (41)
 0.00        runtime-0000:00:1c.2 (38)
 0.00        runtime-0000:00:1c.3 (31)
 0.00        runtime-0000:00:1d.0 (36)
 0.00        runtime-0000:00:1e.0 (32)
 0.00        runtime-0000:00:1f.0 (42)
 0.00        runtime-0000:00:1f.2 (39)
 0.00        runtime-0000:00:1f.3 (33)
 0.00        runtime-0000:02:00.0 (43)
 0.00        runtime-0000:03:00.0 (40)
 0.00        runtime-Fixed MDIO bus.0 (57)
 0.00        runtime-INT0800:00 (52)
 0.00        runtime-PNP0103:00 (49)
 0.00        runtime-PNP0800:00 (48)
 0.00        runtime-PNP0C04:00 (51)
 0.00        runtime-PNP0C0C:00 (58)
 0.00        runtime-alarmtimer (54)
 0.00        runtime-coretemp.0 (55)
 0.00        runtime-gpio_ich.1.auto (47)
 0.00        runtime-i2c-0 (67)
 0.00        runtime-i2c-1 (63)
 0.00        runtime-i2c-2 (66)
 0.00        runtime-i2c-3 (62)
 0.00        runtime-i2c-4 (65)
 0.00        runtime-i2c-5 (69)
 0.00        runtime-i2c-6 (64)
 0.00        runtime-i2c-7 (68)
 0.00        runtime-i8042 (60)
 0.00        runtime-iTCO_wdt.0.auto (61)
 0.00        runtime-microcode (53)
 0.00        runtime-pcspkr (56)
 0.00        runtime-platform-framebuffer.0 (50)
 0.00        runtime-reg-dummy (46)
 0.00        runtime-serial8250 (59)
 0.10        usb-device-1d6b-0002 (10)
 0.10        usb-device-248a-8366 (11)
 0.10        usb-device-8087-0024 (9)
 0.00        virbr0-link-100 (15)
 0.00        virbr0-link-1000 (16)
 0.00        virbr0-link-high (17)
 0.00        virbr0-nic-link-100 (27)
 0.00        virbr0-nic-link-1000 (28)
 0.00        virbr0-nic-link-high (29)
 0.00        virbr0-nic-packets (30)
 0.00        virbr0-nic-powerunsave (26)
 0.00        virbr0-nic-up (25)
 0.00        virbr0-packets (18)
 0.00        virbr0-powerunsave (14)
 0.00        virbr0-up (13)
 0.10        xwakes (74)

Score:    0.0  (  0.0)
Guess:    2.3
Actual:   0.0
----------------------------------
Learning debugging enabled


Parameter state 
----------------------------------
Value        Name
 0.50        alsa-codec-power (12)
 0.00        backlight (4)
 0.00        backlight-boost-100 (8)
 0.00        backlight-boost-40 (6)
 0.00        backlight-boost-80 (7)
 0.00        backlight-power (5)
 2.33        base power (70)
 1.56        cpu-consumption (3)
39.50        cpu-wakeups (2)
 0.00        disk-operations (73)
 0.20        disk-operations-hard (72)
 0.00        enp2s0-link-100 (21)
 0.00        enp2s0-link-1000 (22)
 0.00        enp2s0-link-high (23)
 0.00        enp2s0-packets (24)
 0.00        enp2s0-powerunsave (20)
 0.00        enp2s0-up (19)
 0.56        gpu-operations (71)
 0.00        runtime-0000:00:00.0 (34)
 0.00        runtime-0000:00:02.0 (37)
 0.00        runtime-0000:00:16.0 (44)
 0.00        runtime-0000:00:1a.0 (35)
 0.00        runtime-0000:00:1b.0 (45)
 0.00        runtime-0000:00:1c.0 (41)
 0.00        runtime-0000:00:1c.2 (38)
 0.00        runtime-0000:00:1c.3 (31)
 0.00        runtime-0000:00:1d.0 (36)
 0.00        runtime-0000:00:1e.0 (32)
 0.00        runtime-0000:00:1f.0 (42)
 0.00        runtime-0000:00:1f.2 (39)
 0.00        runtime-0000:00:1f.3 (33)
 0.00        runtime-0000:02:00.0 (43)
 0.00        runtime-0000:03:00.0 (40)
 0.00        runtime-Fixed MDIO bus.0 (57)
 0.00        runtime-INT0800:00 (52)
 0.00        runtime-PNP0103:00 (49)
 0.00        runtime-PNP0800:00 (48)
 0.00        runtime-PNP0C04:00 (51)
 0.00        runtime-PNP0C0C:00 (58)
 0.00        runtime-alarmtimer (54)
 0.00        runtime-coretemp.0 (55)
 0.00        runtime-gpio_ich.1.auto (47)
 0.00        runtime-i2c-0 (67)
 0.00        runtime-i2c-1 (63)
 0.00        runtime-i2c-2 (66)
 0.00        runtime-i2c-3 (62)
 0.00        runtime-i2c-4 (65)
 0.00        runtime-i2c-5 (69)
 0.00        runtime-i2c-6 (64)
 0.00        runtime-i2c-7 (68)
 0.00        runtime-i8042 (60)
 0.00        runtime-iTCO_wdt.0.auto (61)
 0.00        runtime-microcode (53)
 0.00        runtime-pcspkr (56)
 0.00        runtime-platform-framebuffer.0 (50)
 0.00        runtime-reg-dummy (46)
 0.00        runtime-serial8250 (59)
 0.10        usb-device-1d6b-0002 (10)
 0.10        usb-device-248a-8366 (11)
 0.10        usb-device-8087-0024 (9)
 0.00        virbr0-link-100 (15)
 0.00        virbr0-link-1000 (16)
 0.00        virbr0-link-high (17)
 0.00        virbr0-nic-link-100 (27)
 0.00        virbr0-nic-link-1000 (28)
 0.00        virbr0-nic-link-high (29)
 0.00        virbr0-nic-packets (30)
 0.00        virbr0-nic-powerunsave (26)
 0.00        virbr0-nic-up (25)
 0.00        virbr0-packets (18)
 0.00        virbr0-powerunsave (14)
 0.00        virbr0-up (13)
 0.10        xwakes (74)

Score:    0.0  (  0.0)
Guess:    2.3
Actual:   0.0
----------------------------------

Now we can sets all tunable options to their GOOD setting:

[root@desk mythcat]# powertop --auto-tune
modprobe cpufreq_stats failedLoaded 0 prior measurements
RAPL device for cpu 0
RAPL Using PowerCap Sysfs : Domain Mask d
RAPL device for cpu 0
RAPL Using PowerCap Sysfs : Domain Mask d
Devfreq not enabled
glob returned GLOB_ABORTED
Leaving PowerTOP

Fedora 28 : Godot game engine.

Today I tested the new version of Godot game engine - version 3.0.3 .
You can download it from official webpage.
I used the 64 bit version.
After download and unzip you can run the binary file in your user terminal.
The Godot game engine start with a GUI.
Into the right area of screen into Scene tab two objects: Spatial and Camera.
You need to select or add a WoldEnvironment node.
Take a look to the Inspector and use with New Environment .
Run this with the play icon.
If is all right you can see something like this:

Create e new folder into your project and name it Export.
Copy the mscorelib.dll into this folder.
Go to main menu and select Project - Export and you will see this GUI for export your game.
Press Add button to select Linux/X11 output:
Select Linux and press Export Project button.
Go to Export folder and run from your linux terminal your game.
This game engine working well with Fedora 28 and the export running without errors.

Fedora 28 : ARM programming and testing .

This is a simple tutorial about ARM programming and QEMU:
The test.c program is this :

volatile unsigned int * const UART0DR = (unsigned int *)0x101f1000;
 
void print_uart0(const char *s) {
 while(*s != '\0') { /* Loop until end of string */
 *UART0DR = (unsigned int)(*s); /* Transmit char */
 s++; /* Next char */
 }
}
 
void c_entry() {
 print_uart0("Hello world!\n");
}

Using volatile keyword is necessary to instruct the compiler that the memory pointed.
The unsigned int type enforces 32-bits read and write access.
The QEMU model like in a real system on chip the Transmit FIFO Full flag must be checked in the UARTFR register before writing on the UARTDR register.
Create the startup.s assembler file:

.global _Reset
_Reset:
 LDR sp, =stack_top
 BL c_entry
 B .

Create the script linker named test.ld:

ENTRY(_Reset)
SECTIONS
{
 . = 0x10000;
 .startup . : { startup.o(.text) }
 .text : { *(.text) }
 .data : { *(.data) }
 .bss : { *(.bss COMMON) }
 . = ALIGN(8);
 . = . + 0x1000; /* 4kB of stack memory */
 stack_top = .;
}

Next step is the install of arm-none-eabi x86_64 tools :

[root@desk arm-source]# dnf install arm-none-eabi-gcc-cs-c++.x86_64 
Last metadata expiration check: 1:54:04 ago on Fri 15 Jun 2018 06:55:54 PM EEST.
Package arm-none-eabi-gcc-cs-c++-1:7.1.0-5.fc27.x86_64 is already installed, skipping.
Dependencies resolved.
Nothing to do.
Complete!
[root@desk arm-source]# dnf install arm-none-eabi-gdb.x86_64 
Last metadata expiration check: 1:54:48 ago on Fri 15 Jun 2018 06:55:54 PM EEST.
Package arm-none-eabi-gdb-7.6.2-4.fc24.x86_64 is already installed, skipping.
Dependencies resolved.
Nothing to do.
Complete!
[mythcat@desk arm-source]$ ll
total 12
-rw-rw-r--. 1 mythcat mythcat  60 Jun 15 20:28 startup.s
-rw-rw-r--. 1 mythcat mythcat 288 Jun 15 20:26 test.c
-rw-rw-r--. 1 mythcat mythcat 223 Jun 15 20:29 test.ld

Let's test this with qemu virtual tool ( use Ctr+A and X keys to stop qemu) :

[mythcat@desk arm-source]$ qemu-system-arm -M versatilepb -m 64M -nographic -kernel test.bin
pulseaudio: set_sink_input_volume() failed
pulseaudio: Reason: Invalid argument
pulseaudio: set_sink_input_mute() failed
pulseaudio: Reason: Invalid argument
Hello world!
QEMU: Terminated