We all very often use bash scripts to automatize boring and repetitive tasks. Sometimes in our scripts we need to ask
the user to perform one or more choices interactively: in this tutorial we will see how to use the Bash shell select statement to perform such operation in very few lines of code.
In this tutorial you will learn:
Our objective is to make a dummy query execution run faster on PostgreSQL database using only the built in tools available
in the database.
PostgreSQL server base install up and running. Access to the command line tool psql and ownership of the example database.
HTTP is the protocol used by the World Wide Web, that’s why being able to interact with it programmatically is essential: scraping a web page, communicating with a service APIs, or even simply downloading a file, are all tasks based on this interaction. Python makes such operations very easy: some useful functions are already provided in the standard library, and for more complex tasks it’s possible (and even recommended) to use the external requests module. In this first article of the series we will focus on the built-in modules. We will use python3 and mostly work inside the python interactive shell: the needed libraries will be imported only once to avoid repetitions.
In this tutorial you will learn:
In this tutorial we will learn the basics of the dialog utility, in order to use ncurses widget in our shell scripts. We will see how to install dialog in the most used Linux distributions, some of the common options we can use to alter the behavior of dialog, how to use some widgets; among the others: inputbox, checklist, radiolist and yesno. Finally, we will see how to use the data obtained by the widget processing.
In this tutorial you will learn:
Understanding and learning to use MariaDB and MySQL triggers.
In the previous article we saw how to perform basic HTTP requests using the python3 standard library. When requests become more complex, or we just want to use less code, and we don’t mind adding a dependency to our project, it’s possible (and sometimes even recommended) to use the external requests module. The library, which adopted the “HTTP for Humans” motto, will be the focus of this article.
In this tutorial you will learn:
Our objective is to create a copy of a PostgreSQL database that is constantly synchronizing with the original one and accepts read-only queries.
Privileged access to both master and slave systems
In a previous article we talked about the various type of JOIN we can use in a MariaDB/MySQL database. This time, instead, we take a look at the UNION statement: how it works, how we can use it to combine the result of queries run on different tables, and what are its peculiarities.
In this tutorial you will learn:
On Linux and other Unix-like operating systems, tar is undoubtedly one of the most used archiving utilities; it let us create archives, often called “tarballs”, we can use for source code distribution or backup purposes. In this tutorial we will see how to read, create and modify tar archives with python, using the tarfile module.
In this tutorial you will learn:
This Perl programming tutorial is a great scripting guide to help you fully understand Perl script. Find Perl tutorials and programming examples to master your knowledge of Perl Scripting.
Learning how to extract information out of an html page using python and the Beautiful Soup library.
Compared to XMLHttpRequest and the libraries built around it, like JQuery.ajax, the fetch API defines a more modern and cleaner way of performing asynchronous requests, based on the use of promises. In this article we will see some of the interfaces provided by the API, like Request and Response, and we will learn how to use the fetch method to perform various types of asynchronous requests.
In this tutorial you will learn: