How to create dialog boxes in an interactive shell script

When you install new software in the terminal environment, you may often see informative dialog boxes popping up, accepting your input. The type of dialog boxes ranges from simple yes/no dialog to input box, password box, checklist, menu, and so on. The advantage of using such user-friendly dialog boxes is obvious as they can guide […]
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How to visualize memory usage on Linux

Lack of sufficient physical memory can significantly hamper the performance of Linux desktop and server environments. When your desktop is sluggish, one of the first things to do is to free up RAMs. Memory usage is even more critical in multi-user shared hosting or mission-critical server environments, where different users or application threads constantly compete […]
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How to install LAMP stack (Apache, MariaDB/MySQL and PHP) on CentOS

LAMP stack is a popular server-side software stack which is used to build and run dynamic web sites and web applications on Linux platforms. The LAMP stack is composed of Apache (as an HTTP server), MariaDB or MySQL (as a database backend), and PHP, Perl or Python (as a server-side programming language), and hence the […]
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How to browse and search API documentation offline on Linux

For a programmer, good API documentation is worth more than a library of programming textbooks. If you are an avid developer, you probably want to make your life easier by keeping all necessary API documentation right at your fingertips. Most IDEs provide brief tooltips or IDE-specific ways of incorporating API documentation. However, these are mostly […]
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How to create and manage LXC containers on Ubuntu

While the concept of containers was introduced more than a decade ago to manage shared hosting environments securely (e.g., FreeBSD jails), Linux containers such as LXC or Docker have gone mainstream only recently with the rising need to deploy applications for the cloud. While Docker is getting all the media spotlight these days with strong […]
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How to install LEMP stack (nginx, MariaDB/MySQL and PHP) on CentOS

The LEMP stack is an increasingly popular web service stack, powering mission-critical web services in many production environments. As the name implies, the LEMP stack is composed of Linux, nginx, MariaDB/MySQL and PHP. nginx is a high performance and lightweight replacement of slow and hard-to-scale Apache HTTP server used in the traditional LAMP stack. MariaDB […]
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How to download an ISO image with BitTorrent fast and safely from the command line

If you are one of those guys who have urge to try out every new (or even beta) release of Linux distribution to satisfy your curiosity and stay up-to-date, you will need to deal with the hassle of downloading big ISO images every now and then. ISO providers typically put up .torrent file of their […]
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What is a good command-line calculator on Linux

Every modern Linux desktop distribution comes with a default GUI-based calculator app. On the other hand, if your workspace is full of terminal windows, and you would rather crunch some numbers within one of those terminals quickly, you are probably looking for a command-line calculator. In this category, GNU bc (short for “basic calculator”) is […]
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How to verify the authenticity and integrity of a downloaded file on Linux

When you download a file (e.g., an installer, an ISO image, or a compressed archive) from the web, the file can be corrupted under a variety of error conditions, e.g., due to transmission errors on the wire, interrupted download, faulty storage hardware, file system errors, etc. Such failure cases aside, a file can also be […]
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