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Author Archives: bitjunkie
Extra Disk Space on Linux – For Free! :-)
Today, I held a class on file systems, during which I demonstrated how to create a mountable image file on Linux. After mounting the image, my students and I somehow got to wonder what would happen, if you copied or … Continue reading
Posted in Fun, Linux, Non-technical, Uncategorized
Tagged container, file systems, image, linux, mkfs, mount, weird stuff
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The Brilliant Concept of Standard Streams in Unix (1)
1. The basic idea of standard streams In the 1980s, almost every book or class on computer science here in Germany started with an explanation of the EVA-Prinzip, where E stood for Eingabe (Input), V for Verarbeitung (Processing), and A … Continue reading
How to use ancient Morse code to solve a modern problem
If you own a Raspberry Pi mini computer the following problem may sound familiar to you: You just connected your Rasperry Pi to a network with automatic DHCP. Now you need to find out what IP address has been assigned … Continue reading
Posted in c, Information Theory, Linux, Raspberry Pi, Uncategorized
Tagged c, dhcp, gpio, ip address, linux, morse code, programming, Raspberry Pi
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Let’s make the stack explode in Java!
In one of my lectures about memory management in Java, I was looking for a quick and simple way to demonstrate the influence of local variables on the stack memory usage. So what came to my mind was this: Local … Continue reading
Posted in Java, Programming Essentials
Tagged java, memory management, runtime environment, stack, stack overflow, virtual machine
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A simple way to obfuscate string literals
By Andre M. Maier While I was sitting in a doctor’s waiting room last week, it occurred to me that I could send out a geeky holiday greeting to my younger programming students. Naturally, as a teacher, I wanted to … Continue reading
Posted in Information Theory, Java, Programming Essentials
Tagged characters, education, java, obfuscation, programming, strings
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Why Linux DOES NOT Suck
By Andre M. Maier On October 5, 1991, Linus Torvalds officially published the first version of his homemade Linux kernel. Today, 24 years later, a large number of IT professionals agree that best of Linux is yet to come. I … Continue reading
Posted in Linux, Non-technical
Tagged education, free software, linux, open-source, unix
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Let’s make the heap explode!
This blog entry is dedicated to those who teach computer science at high schools and vocational schools. In one of my Java programming classes, only few of the students showed up. It didn’t seem to make sense to continue with … Continue reading
Posted in Java, Linux, Programming Essentials, Uncategorized
Tagged efficiency, garbage collection, heap, java, memory, Object Oriented Programming
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Floating Point Representation
Back in the days when I was in middle school, I started to develop a strong preference for “nice” and “short” numbers, such as 0.1. One likely reason was that any math problem in school was designed to yield a … Continue reading
Posted in Bit-Twiddling, Math, Uncategorized
Tagged double, exponent, float, floating point, ieee754, mantissa
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Pointers and References – Part 4 (Hacker Stuff) ;)
Ok, guys … party’s over. Some of you have requested some more in-depth stuff on pointers, so here we go: Function Pointer Arrays. Depending on your previous programming experience, Function Pointer Arrays (FPA) may seem a bit nerdy to you. … Continue reading
Posted in Pointers, Programming Essentials, Uncategorized
Tagged array, function, function pointer array, pointer
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