Year: 2021

Home » 2021

Using the ‘sleep’ Function in Bash Scripts, with Examples

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Bash sleep Command

This article explains the sleep command in Bash/Shell scripts and how and why you might use it. The sleep command in Bash (and other Linux Shells) pauses execution for a specified amount of time – halting the script for a set number of seconds, minutes, hours, etc. Why Pause Execution? Why would you want to pause executing your script? Give the user a chance to interrupt an automated action Await user input Wait for a device to warm up/become available Stop text from flying across the screen if you’re trying to … Read more

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Converting to Integer with JavaScript parseInt() [Examples]

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JavaScript parseInt

This article will show you how to use the parseInt() function in the JavaScript programming language. JavaScript is notoriously loosely typed – meaning that variables of one type (e.g., strings of text, numerical values, boolean values) are converted to others, allowing you to perform mathematical operations on strings and silly things like that. This causes all sorts of issues – strings containing numbers may not be parsed to the expected value, and all of a sudden, you have angry clients wondering why your shiny new … Read more

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How to List Users and Groups in Linux, With Examples

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Linux List Users Groups

Linux supports multiple users and groups, allowing access to be granted to only the resources required.  Here’s how to list users, groups, and group membership. Separating users and groups ensures that different people can’t accidentally interfere with each other’s files and ensures system security by denying access to vital system files. This article details the various ways to query the users and groups on a computer running a Linux Operating System. Listing All Users The /etc/passwd file is a text-file database containing information on all of the users … Read more

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How to Change the Hostname in Linux (Debian, Ubuntu, Arch, RedHat)

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Linux Change Hostname

This article will show you how to change the hostname for your Linux device (Debian, Arch, Ubuntu, or RedHat). The methods below should work for the vast majority of current and obsolete Linux Distributions. What is the Hostname? The hostname of a device on the network is the human-readable label of the system. It can be used to identify or connect to a system on the network instead of connecting to it via an IP address. Displaying the Current Hostname Regardless of your distribution, you can find out … Read more

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The MySQL/MariaDB ‘SHOW INDEX’ Statement, With Examples

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MySQL SHOW INDEX

This article shows you how to use the MySQL SHOW INDEX statement to list the details of indexes and keys in a table. To use the SHOW INDEX statement, you will need to know which database and table you wish to view index information for. Looking to list the databases and tables on your system? What Are Indexes? Indexes are a tool that allows a database to quickly lookup data in a table for a certain column. Usually, when searching a table, the database software must read every row in … Read more

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The MySQL/MariaDB ‘DISTINCT’ Statement, With Examples

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MySQL Distinct

The MySQL DISTINCT operator returns only unique values from a column from a database table; duplicates are not returned.  Here’s how to use it. The DISTINCT operator can be useful in many scenarios; for example, you may want to generate a list of countries you have shipped to, or you may want to provide a drop-down menu containing unique product options for the user to select. Example Usage of MySQL DISTINCT Examples will use the following table: table_orders: order_id shipping_country product_category 1 Australia soap 2 China … Read more

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The MySQL (and Maria DB) TRUNCATE Command, With Examples (And Warning!)

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MySQL Truncate

MySQL (and its functional equivalent, MariaDB) have two things named TRUNCATE – so watch out which one you want to use or suffer dire consequences! This article outlines the difference and usages of the MySQL TRUNCATE function and TRUNCATE TABLE statement – they share similar names but do very different things. TRUNCATE Function – Truncating a Number to a Certain Number of Decimal Places First, the TRUNCATE function. The TRUNCATE function reduces the number of decimal places for a given number. MySQL TRUNCATE Function Syntax TRUNCATE(number, decimals) Note that: number is a number decimals is an integer … Read more

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The Difference Between JavaScript and Node.js – Which Should I Use?

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JavaScript vs Node JS

This article explains JavaScript and Node.js and their relationship with each other. What is JavaScript? JavaScript has become one of the most popular programming languages for building web applications and has even become a contender for building solid desktop and mobile applications. In the browser, there is no competitor – browsers run JavaScript for their client-side code- allowing them to pop up windows, disable buttons, animate screen elements, and retrieve data. This is what JavaScript was built for. What is it Good For? JavaScript Runs … Read more

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isdigit(), isalpha() and Other Checks in Python, With Examples

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Python isdigit isalpha

Both Python versions 2 and 3 provide several helpful string methods that let you find the string’s contents.  Here’s how to use them. The functions in this article are useful if you want to validate user input – for example, you may want to check that a user-inputted string is a valid number before converting it to a number variable to prevent errors and warn the user that they need to try again. isdigit() and isalpha() are commonly used methods to identify a string’s contents, but … Read more

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How to Round Numbers Up/Down/Nearest in Python

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Python Round Numbers

This article will show you how to round numbers up, down, and to the nearest 1, 10 100 (or any number) in the Python programming language. Truncation vs. Rounding Truncation isn’t technically rounding, but it serves a similar purpose, so I’ll include it here. It’s the simplest way to shorten a number – just cutting off the characters at the end until it’s in the format you require. Rounding gets the nearest number, whereas truncation cuts off digits from the number. For example: To round 2.9 to … Read more