It is probably just a barcode checksum/error code, otherwise they wouldn't have to rely on the values of the first 8 digits. Instead they should generate 4 random digits and store them in the database along with other information, then it basically works like a pin number (and xor it with a proper checksum).
Edit: If it is really a checksum, it is a crappy one.
It is called a struct. It holds arbitrary collection of any type of data safely while enabling the lazy programmer to pass only one parameter around. It is also safe (as must as it can be in C) unlike pointers that hide data behind their back and are just asking for trouble.
I will ignore all the problems and point out the worst offender, stack allocation example. That is not how you allocate arbitrary data on the stack, automatic char array is not malloc. In fact, in C you can't do it without using special platform specific functions. Anything else will cause undefined behavior.
You can find them online. Some might require root some don't. They can also enable complete programmability and deep iteraction with the system if needed, unlike macros.
Using scripts works out of the box without hacking for ages as well. You only need to write the script once, and then share it with the world. This is the point I made in other comments already which you read but ignored the point.
>"Storing the mapping on a large device doesn't make sense" - I agree about this, the large device being a bulky host computer.
Strawman. The large device is the keyboard you need to lug around. Tell me, is your keyboard designed for use with a computer?
>Various OSes have various (sometimes quite severe) limitations regarding remapping and the "script" that you mention is also OS-specific which is a pain if you use multiple OSes.
No. It isn't a pain, it called hacking and you only need to do it once and it is free and shareable. So in this sense only one person has to do it once and it just works for everyone else from then on.
Yes. See my comment below. The bug is trivially avoided by adhering to a coding standard that actually makes the code better. See my other comment below.
The keyboard boasts itself as a the ultimate hacking keyboard, yet the only "hackable" thing that can be done with it is configuring keys and macros, which can already be done for free on any OS and with any standard keyboard. The keyboard doesn't deserve its name in my opinion. It also costs 220$ (200$ as an early bird) .
Rhetorical question: Who will benefit the most from this project?
It is still almost always worse. Storing the mapping on a large device doesn't make sense, when you can store a script online or in a small storage device if internet access is a problem somehow, and it works with every computer that has a standard keyboard. Just like the drivers, script has to be written only once, but has the benefit of sharing with any other user for free without requiring special hardware.
The benefit seems to be low level systems where it is hard to script the key mappings (assuming drivers work). But do you really write your code, i.e. spend a significant percentage of time in them, or in moderns OSs?
As for comfort, buy a ergonomic keyboard that is cheaper and static and will force you to adapt the correct posture. Especially if the problem is the small additional angle required to touch type, those keyboard solve it.
I don't get it. This problem can be solved in software, no special hardware required.
Ergonomic aspect is also misguided since touch typing correctly on a standard qwerty keyboard will not bend wrists, so no need to split the keyboard in half. Your hands need to be at an angle to type (look at the keys, columns are offset to create an angle), if they are perpendicular you need to learn touch typing correctly.
gcc also doesn't detect the unused variable. Looking at the -Wunused warning description it does so correctly since a variable is considered unused if it is declared only. In this case it is also used as a parameter.
To detect it, split the recursive function into two, one that recurses and one that does the job at the end. Both can take the same relevant arguments and the latter function will detect any unused parameters.
>No, she has been personally harassed due to the area she is working in.
I'm glad you figured it out. The rest of your comment is a strawman.