System Code Geeks Operating System Developers Resource Center

In this post, we feature Virtualization with VirtualBox. This article is part of our Academy Course titled VirtualBox Tutorial: Virtualization Essentials. In this course, we provide a compilation of VirtualBox tutorials that will help you get started with this virtualization platform. We cover a wide range of topics, from installing the software and performing a basic configuration, to cloning, exporting, ...

We often need to store structured binary data in our database – images, pdf documents, etc., but also have a need to search by, or index on, attributes of that data. E.g., we might store the height and width of an image, or the OCR text from a PDF document (for full text searches). The normal solution is to store ...

In this post, we feature comprehensive Linux cut Examples. Cut is a Unix command line utility which is used to extract sections from each line of input, usually from a file. It is currently part of the GNU coreutils package and the BSD Base System. It first appeared in AT&T System III UNIX in 1982. Extraction of line segments can ...

Course Overview In this post, we feature a comprehensive Apache HTTP Server Tutorial. The Apache HTTP Server, colloquially called Apache, is the world’s most used web server software. Originally based on the NCSA HTTPd server, development of Apache began in early 1995 after work on the NCSA code stalled. Apache played a key role in the initial growth of the ...

In this post, we feature a comprehensive Apache URL rewrite example. This article is part of our Academy Course titled Apache HTTP Server Tutorial. In this course, we provide a compilation of Apache HTTP Server tutorials that will help you get started with this web server. We cover a wide range of topics, from installing the server and performing a ...

I finally have a breather and can start working through my backlog of ideas. I start with some background that will make the motivation for subsequent posts clearer. What are the threat models for the persistence layer of an application, specificially the threats against the database itself? Remember that a ‘threat’ is an adverse act, whether intentional (by an attacker) ...

We are living the era of buzzwords, and Docker is for sure one of those in the technological landscape. Docker has a common sense definition: hypervisor-free virtualization. In other terms: running VMs without any hypervisor-based virtualization support. Now, how is this possible? What is the arcane trick to achieving that? Let’s live a short journey to sketch the context out, ...

Many experienced database developers are familiar with user-defined functions implemented in SQL or a procedural language. PostgreSQL itself supports PL/pgSQL, PL/Tcl, PL/Perl, PL/Python, and has third-party support for PL/sh, PL/Java, PL/Ruby, PL/PHP and even PL/R. Recent versions of PostgreSQL also support SQL/MED (foreign data) with foreign data wrappers (FDW). This allows the database user to access foreign data sources – ...

The find command is one of the versatile commands in UNIX and Linux  and I used it a lot in my day to day work. I believe having good knowledge of it and understanding of its different options and usage will increase your productivity a lot in UNIX based operating system e.g. Redhat Linux or Solaris. If you are a QA, support ...