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In this article, we will learn how to setup and configure Ruby on Rails which is the most popular stack application used by the developers which is used to create sites and web applications. The Ruby is a programming language where the programer’s use with the combination of Rails development framework to make the application development fast and simple.‘rbenv’ is the command-line tools used to install the Ruby and Rails which also provides a good environment for application development using Ruby on Rails. ‘rbenv’ provides the application specific versions of Ruby.PrerequisitesWe needed an Ubuntu 16.04 installed machine with a non-root ... Read More
In this article we will learn about how to set up Postfix on Ubuntu 16.04, Postfix is a very popular open-source MTA (Mail Transfer Agent) which can be used to relay the emails on Ubuntu Linux systems, most of the public mail servers over the real world use the postfix only.PrerequisitesTo complete this demo we needed the followingA machine with Ubuntu 16.04 installed and a non-root user with sudo permissions on the machine.A (FQDN) fully Qualified Domain Name points to the machine.We assume the Domain FQDN mail.mydomain.comInstalling the PostfixAs Postfix is available with Ubuntu default repository we can directly go ... Read More
Shiny is an R package that allows Linux users to convert R code into an interactive webpage and documents online. You can take your shiny apps and share them in your organisation or the world. This article explains about how to set up shiny server on Ubuntu.Installing Shiny Server on UbuntuBefore installing Shiny server, we need to install the shiny R package. To install R packages, use the following command –$ sudo apt-get install r-baseThe sample output should be like this -Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are ... Read More
In this article, we will show you how to set up multiple SSL Certificates on a CentOS with Apache using a single IP address only. In general, a website administrator is restricted to use a single SSL Certificate per socket with an IP which will cost a lot of investment to the company. This restriction may lead them to buy multiple IP addresses for HTTP’s websites for their domain hosting or buy hardware that allows them to utilize multiple network adapters.This is allowed by an extension to the SSL protocol called Server Name Indication (SNI). Most current desktops and mobile ... Read More
In this article, we will learn about how to setup and configure the Apache Web server to restrict from visitors without authentication where we can hide some important and critical information to the un-authenticated users.PrerequisitesWe needed an Ubuntu machine with a non-root user with Sudo privileges.An Apache2 web server installed on the machine.Installing the Apache UtilitiesWe needed to install an Apache2 utility package called ‘htpasswd’ where this utility is a part of ‘apache2-utils’ packages.This will help us to create and manage the username and password which is needed to access the restricted part of the website.Below is the command to ... Read More
To match any single character in the given set with JavaScript RegExp, use the [aeiou] metacharacter.Example JavaScript Regular Expression var myStr = "Welcome to our website!"; var reg = /[we]/g; var match = myStr.match(reg); document.write(match);
To match any single character outside the given set with JavaScript RegExp, use the [^aeiou] metacharacter.Example JavaScript Regular Expression var myStr = "Welcome!"; var reg = /[^lc]/g; var match = myStr.match(reg); document.write(match);
In this article, we will learn how to setup and configure Jekyll Development Site. Jekyll provides the benefits of the Content Management System (CMS) with performance and security which appears in the database-driven sites. It is also called as blog-aware which has features of handling the date-organized contents. It is especially suitable for the people who work off-line, which also provides the lightweight editor with content management which has the version control for tracking the changes made on their websites.PrerequisitesA machine with Ubuntu 16.04 installed.A user with Sudo permissions on the machine.Installing the Jekyll Development Site on Ubuntu 16.04Before we ... Read More
This article will teach you on, how to schedule a corn job for executing a script or command or shell script at a particular time every day. As a system administrator, we know the importance of running the routine maintenance jobs in the background automatically. The Linux corn utility will help us to maintain these jobs to run in the background.General Syntax of a Cron JobMIN HOUR Day of month Month Day of Week Command 0-59 0-23 1-31 1-12 0-6 Any Linux command or scriptTo see a list of cron jobs which exists on the machine, run the below command ... Read More
Do you know how to remove empty lines from the file in Ubuntu? It may also be performed manually if the file has few strains but if the file has hundreds of thousands of line that is tough to be accomplished manually. This article explains you about – how to remove empty lines from a file on Ubuntu.Our sample file should be like this –Use the following command to remove the Empty lines from a file as shown below –$ ex -s +'v/\S/d' -cwq abc.txtIn the above command abc.txt indicates the file name. The sample output should be like this ... Read More