Daily commit

From ~/pr/gitl/ocaml-gol In a constant effort to learn new programming languages, I'm currently trying to use ocaml , a free and open-source general-purpose, multi-paradigm programming language maintained at the Inria . It's basically an extension of Caml with object-oriented features. I'm mostly interested by its functionnal and pattern matching features but the module part of the language can be a bit difficult to understand for someone with little to none ML (Meta Language) background.   The error When trying to use the graphics module to create a graphical window and go just a little further than the simplest helloworld program, here is the result : If the project uses dune : (executable (name ocaml_project) (libraries lwt.unix graphics) ) with this code : let () = Printf.printf "Hello, world!\n";; Lwt_io.printf "Hello, world!\n";; Graphics.open_graph " 800x600";; The first times I built this project running the du...

Qt is a cross-platform application framework and widget library written in C++. It is shiped with a form designer simply called designer which save the created mockup in XML format with the .ui extension. While Qt is generally used with Qt its own build called qmake and a project file, if you need external dependency checks and more control on the building process, you may want to use it with cmake .   The .ui form The .ui file contains the form definition. The simplest way to get one is to create it using the designer tool but this is plain XML so you can copy/paste it with a simple text editor as well. Let's call it form.ui : <?xml version="1.0" encoding="UTF-8"?> <ui version="4.0"> <class>Form</class> <widget class="QWidget" name="Form"> <property name="geometry"> <rect> <x>0</x> <y>0</y> <width>400</width> ...

While writing unit tests for a ruby project, headers-date , I had to unit test a function that print some useful debugging informations in terminal using IO#puts stdlib function. This code originally was posted to the following google group . The tested class Let's imagine a to-be-tested class that use puts , print or p IO methods to print some text to stdout (or stderr ). class TestMe def print puts "Some useful text" end end The capture trick To help testing the printed text, we will implement a new function called util_capture . It simply temporarily replace both $stdout and $stderr variables. The dollar sign prefix (sometimes called a sigil )in ruby is used to identify global variables . Here are really sparce official documentation on $stddout and $stderr The yield keyword will be replaced by your block. def util_capture require 'stringio' orig_stdout = $stdout.dup orig_stderr = $stderr.dup captured_stdout = ...

A singleton is a class that can only be instantiated once. The design pattrern restricts the class to one single instance and further access will always return the same, first one. As explained in the singleton.html page, the boost serialization library has a Singleton class defined in the shipped Singleton.hpp C++ header. Dependencies On arch -based distributions, such as manjaro , this header is part of the extra/boost package. On Debian Bullseye , it is part of the libboost1.74-dev one but it's a dependency of the libboost-dev dependency package. So, according to your distribution, use the needed command : sudo pacman -S boost or sudo apt-get install libboost-dev Usage As seen in the boost class interface documentation, to use it, you just have to create a class that inherits the singleton one. Here is an example class that use boost's singleton to ensure one and only one instance will be in use : #include <boost/serialization/singleton.hpp> ...

This trick comes from a brand-new project I hosted at github : elecrud , more specifically the MainWindow::onFileOpen() method you can find in the src/editor/MainWindow.cpp file.   The dialog class The FXFileDialog class reference can be found online here for the 1.6 version of the fox toolkit library. So, obviously, you could instantiate FXFileDialog but the simplest way to use it is to use Static Public Member Functions , for example getSaveFilename() or getOpenFilename() : FXString filename = FXFileDialog::getOpenFilename(this, "Open a project...", "~"); // use filename here The owner class The only limitation is that you must have a valid owner as first parameter. If you try nullptr you may have a silly segmentation fault . The simplest solution is to call it from a class that inherits a Fox class, for example a MainWindow : class MainWindow : public FXMainWindow { // Macro for class hierarchy decla...

Well, this name is a bit weird but the project's still cool and since it's a new project, here it is : elecrud is a C++ fox-toolkit-based multi-user CRUD operator electron application generator. The goal is to create a lightweight yet portable graphical application used to edit and generate an electron application used to feed and edit a persistant set (i.e. a database) via standardized CRUD operations. Presentation This project is mainly a way to keep learning fox-toolkit , a very lightweight, open source and cross-platform widget toolkit libray licensed under LGPL. The main advantage of this toolkit, apart being lightweight is to have the same lookn-n-feel on all plateforms. While the first steps of the project seems pretty straightforward ( mainwindow and menu stuff), project serialization thing, the electron application squeleton and generation may fastly become challenging. The application is available under GPL v3 or later and hosted at github : https:/...

In the RainbruRPG 's LocalTest class, we show the map generation progress from libRLGL using a LoadingBar. The loading informations simply come from a Publisher/Subscriber design pattern from the LoadingBarListener override. Following examples are obviously implemented in C++. It should correctly build on every compiler with, at least, C++11 support. The PubSub design pattern This design pattern involves at least three classes. Here is an example UML diagram done with umbrello , a free and open source UML modeler licensed under GPL 2 or later : In this example, the Publisher class will be able to send message to an arbitrary list of classes that inherits the Listsner abstract type. From the Publisher point of view The publisher side needs at least a base class to be overridden by the subscriber and a list of subscribers : #include <vector> class Listener { public: virtual void message1()=0; virtual void message2()=0; virtual void message3()=0; }...

If you use cmake to configure a project, whatever the programming language the project is written in, you can and certainly already use the configure_file() cmake function to copy a file and modify its content using variables substitution. The configure_file function While this trick is generally used to generate, often plateform-dependant config.h from a config.h.in template, it can be used to generate arbitrary file using variable substitution. For example, Doxyfile , the file used to generate doxygen API documentation Destination directory You can also change the destination directory of the file. For example, often, we use a build/ subdirectory to call cmake from to avoid project source tree pollution : configure_file( "${PROJECT_SOURCE_DIR}/config.h.in" "${PROJECT_BINARY_DIR}/config.h" ) The variables are PROJECT_SOURCE_DIR and PROJECT_BINARY_DIR to change the source and destination directory of the generated file. If you...

By mystake, I called rm on a complete directory and the result is awful and predictable : all files were correctly deleted. Just after, I searched for a solution. Install needed package We will use a free and open source software licensed under GPL v2+ called TestDisk . First, install the testdisk package using your distribution's package manager. On debian -based systems : sudo apt install testdisk or on arch -based distributions such as manjaro : sudo pacman -S testdisk Gathering informations Before starting the restoration process, you'll need some informations : The df -m command can help you find this information from the mount point the deleted file was on : Filesystem 1M-blocks Used Available Use% Mounted on udev 4949 0 4949 0% /dev tmpfs 999 10 990 1% /run /dev/sda1 23339 10168 11963 46% / tmpfs 4993 173 4820 4% /dev/shm tmpfs 5 1 ...

RainbruRPG is an open-source MMORPG project I'm working on since someday in early 2010's. I already posted multiple posts on this project (for example here and here ). While its development is actually in pause for a while now, it is a great project to learn using new 3D/UI oriented libraries. CEGUI (short for Crazy Eddie's GUI System ) is one of these libraries. It is a free MIT-licensed windowing and widgets library that run on top of Ogre3D but it can also run on other backends. The RainbruRPG's not yet implemented modal dialog The modal need While CEGUI is a great library to create windows and complex screen, I need a standard dialog for NYI (Not Yet Implemented) features. For this, I'll try to create a modal dialog, i.e. a dialog with a blocking exec() function and a return value. It can have multiple buttons, each possibly with a different value but the blocking execution is needed : ModalDialog md; if (md.exec()) { // handle positive eve...

This issue comes from some research for RainbruRPG while working with openssl function (see NewProfile class). This C function is waiting for a void* parameter as passphrase, and I'm getting the user-entered password as a std::string .   The problem is, if you try to pass it directly, use get the following error : error: cannot convert 'std::string' {aka 'std::__cxx11::basic_string '} to 'void*' To pass it to the legacy void* function, you just need to pass a pointer to the first element of the string : #include <string> #include <iostream> void waiting_for(void* str) { using std::cout; using std::endl; // You have to cast it or you'll print the pointer // address instead of the string content cout << (char*)str << endl; } std::string passphrase = "whatever"; waiting_for(&passphrase[0]); This trick also works with char* but you have to cast the result (at least on g++ ) to av...

The mrt-manager homepage When trying to run mrt-manager , a  meteorjs project, on a newly installed Debian Stretch , I had the following issue : Unexpected mongo exit code 1. Restarting. Unexpected mongo exit code 1. Restarting. Unexpected mongo exit code 1. Restarting. Unexpected mongo exit code 1. Restarting. Unexpected mongo exit code 1. Restarting. Can't start Mongo server. MongoDB failed global initialization I got this issue when trying to work on mrt-manager after a fresh Debian install. This issue is due to a missing locale , a set of language/country code pair used to define user interface language in i18n context. You probably installed your favorite GNU/Linux distribution in your native language and you didn't installed the english locale. Edit the /etc/locale.gen as root and uncomment the following line : en_US.UTF-8 UTF-8 Then execute the following command as root : #locale-gen Now, reboot the computer and mongodb should start.

I'm not dead yet and neither is my code. This blog, however is, and I will try to fix that.   Actual state The truth is that, these days, I was more into streaming and competitive programming than traditionnal, more serious development. I splitted my dev repos in two different accounts, bitbucket for all professional-related and old work and a « new » gitlab account, used for game-related ans streamed repositories. While my old dev name remains *rainbru*, my new streamer name is now discontinued. The new repositories will created at github with a big focus on company/industry-related project, mainly written in C++,ruby,perl and JS. This will give daily commit if I can, side by side with an active work on freecodecamp and mit's ocw daily work tyo heavently have some certifications. Reactivation So, I'll try to reactivate this blog, trying to post some dev-related articles more than once in a five years span. Btw, today is also my birthday -- yippee!