A series of little how-to guides and tutorials for the C programming language.
Reinstating all my old online content has led me to some dark corners of my laptop hard drive. It pains me, sometimes, to think of what I would be doing now if I had twigged earlier on in my life that consistency trumps intelligence, talent or sporadic effort. Many years ago I had an idea…
I thought we could take a quick look at how to create a shared library out of our code. This week we’ll create the library and next week we’ll look at the various ways of installing/accessing it on the operating system. I’m going to re-use the palindrome program I’ve talked about before (a proper version, not the dodgy…
Last week’s challenge was a tough one, so don’t be alarmed if you had no idea what the issue might have been. Also, it can be hard to spot problems in a functional program because you tend to concentrate on what the code is actually doing, rather than the validity of the code itself. To give…
I have a challenge for you. Is there a problem with this code? It compiles without warnings, and runs as expected. I’ll reveal all next week. Have fun! g++ -g -Wall palindrome_problem.cpp #include <iostream> #include <string.h> using namespace std; char* isPalindrome(char* word) { char* ret = 0; ret = (char*)”Yes! This is a palindrome.”; char…
atoi and iota seem like perfect partners. atoi is the ‘ascii to integer’ function and itoa is the reverse, the ‘integer to ascii’ function. You would use atoi to convert a string, say, “23557” to the actual integer 23557. Similarly, you would use itoa to convert an integer, say 44711, to the equivalent string “44711”….
You’re probably all aware of the Fibonacci number sequence. Starting with 0 and 1, the next number is determined by the sum of the previous two numbers, so the sequence begins: 0, 1, 1, 2, 3, 5, 8, 13, 21, … This is a mathematical concept, and it is defined by a “recurrence relation” (that’s…
I’m going to use a simple program to illustrate the basic use of pthreads, and highlight some of the issues that you may run into when you’re creating your own threaded programs (for C++11 threads, see this post). I want my program to print a message from each thread I create, to the console, in a…
I’ve seen this odd error several times over the years, almost always after first importing a new project into Eclipse-CDT. After import, when you try to build your project, it just returns the message make: Nothing to be done for all in the console. And then, once you’ve got the error, nothing you do will kick your…
Now we’ve got one LED up and running, it’s pretty easy to expand this to make a light bar like K.I.T.T.’s. Step 1 – Wire up the breadboard The next thing we need to do is switch everything off, and then wire up the breadboard as per the circuit diagram below. Leave the female ends…
This is the first part of a two parter on creating the K.I.T.T. light bar with LEDs using your Pi (I know, awesome, right?). Here’s mine in action: In this section we’ll install the wiringPi library on the Raspberry Pi, connect up a single LED, and write a simple program in C to make it…