Laur IVAN

Execute a Command in Every Directory with Bash

Posted by in Software, Tutorial

TL;DR: Use a find-based loop The other day I was wondering how to execute a command in each sub-directory of a project. In python, you have os.walk. In C, I would’ve probably written myself something just for fun etc. In shell, I know you have find which is capable of finding all directories (find (dir) -type d). All I need to do is to wrap this in a loop and for this one has two options: Commmand line style

or

Script style with a loop

The choice…read more

Build Update Statements with Oracle SQL Developer and Python

Posted by in Software, Tutorial

By default, SQL Developer can only export INSERT statements. This is quite unfortunate when one needs to build UPDATE statements because their syntax is different. I’ve tried to use regexp to convert the statements but I didn’t find it not straight forward at all. So, I cam up with the following strategy: Export the data as JSON Use a python script (below) to write the statements The python script We first need to specify things like the DB Schema, table and the primary key:

Subsequently, I’ve defined a wrapper…read more

How to Develop Pipelines – Some Best Practices

Posted by in IT, Software

These days I’m developing a bunch of pipelines to automatise the build/deployment process. Here are some things I’ve learned: How to develop Initially, I’ve started developing the pipeline as any other program: Create a repository, fire my editor, write a Jenkinsfile and use the Pipeline script from SCM. While the result is exactly what you want to have at the end, the edit-deploy-run cycle becomes a chore and it’s quite unpleasant at the beginning (I had a bunch of typos for example), so DON’T. Instead, create a simple pipeline with…read more

Fade colors in Corona using Transitions

Posted by in Software, Tutorial

Corona provides transitions. According to this post, a transitionTo(…) would suffice:

The user can also cancel the transition if needed (which is waht I would need to do later in the code). In case you’re into custom stuff and the easing functions are not enough, you can create your own. A sample can be found here. The signature of the easing function is (at the moment of writing) function customEasing(t, tMax, start, delta) where: t is the time elapsed since the start tMax is the duration of the transition…read more

Fade Colors on a Polygon using the Game Loop

Posted by in Software, Tutorial

One of the features I need to implement is to smoothly change the fill/stroke color of a polygon, like this: A manual approach In order to better understand the mechanics, I built my own fading PoC. First, one would need to build the polygon:

In this particular case, I have a text field and a rounded rectangle beneath it. the hud group contains both in the right order. Once the components have been created, we build the function to be called each frame:

The idea is to only…read more

Antialias a Polygon with Corona SDK

Posted by in Software, Tutorial

The other day I figured I needed to draw a polygon in Corona SDK. With display.newPolygon(...), the job is extremely easy and a result like (apologies for the JPEG artefacts): It is obvious that in non retina cases, one can see the aliasing of the polygon’s edges. Hence I’ve thought and searched of various ways to provide the polygons with antialiasing. The sum of solutions I found is: Find a flag to enable antialiasing for a polygon Use effects to perform e.g. a blur or a glow and adapt it…read more

Ignore ESLint Directives in Code

Posted by in Software, Tutorial

The other day I’ve had to refactor a piece of angular code. Unfortunately, the original code was written a long time ago and has some issues like having $scope in controllers and a rather large number of unused variables. changing the $scope to this is a very time-consuming task as it implies prefixing functions and variables in the HTML code as well as selective replacements in JS ($scope.$watch for example must remain intact). In order to minimise the effort, I’ve decided to only move the code blocks around using John…read more

Monitor ethOS Distro with Elastic Search – 3

Posted by in IT, Software, Tutorial

Once we’ve set up the data sending from out ethOS machine, we can check that ElasticSearch collects data. With GET /ethos/_count, we get something like:

If the count is greather than 0, we can start analysing the data. Metrics I am currently measuring only machine. Therefore, I’ve set up some simple measurements: Hash rate Temperature Network Fan speed Hash rate I am measuring the average sum of all GPUs’ hash rates and the trend: I’ve built this with Timelion and the code is:

As you can see, there…read more

Proxy Content from URL with Webpack Dev Server

Posted by in Software, Tutorial

An application I’m working with has a large amount of static files (path starting with ‘/files/’) deployed on a mounted volume in Docker. They are subsequently served via nginx. for local development, I thought of two options: Add files to the local dev server (e.g. copy assets) Build a proxy to pipe the request to the nginx-served site The first option is somewhat restrictive: I’d have to make sure the files are kept in sync with the latest version. I’d have to integrate the syncing process with the build scripts….read more

Monitor ethOS Distro with Elastic Search – 2

Posted by in IT, Software, Tutorial

Following the previous post, we are now in position to install the monitoring code on the monitoried machine, of course. The easiest way is to download the code on the machine in /home/ethos. Following steps will assume you have the unpacked code in

Once you have downloaded the code, you need to add the location of the ElasticSearch server to the local.conf:

Dissecting the scripts The scripts are written in PHP, like ethOS‘s own scripts. I did that for two reasons: Take advantage of the already written code…read more