Join devRant
Do all the things like
++ or -- rants, post your own rants, comment on others' rants and build your customized dev avatar
Sign Up
Pipeless API
From the creators of devRant, Pipeless lets you power real-time personalized recommendations and activity feeds using a simple API
Learn More
Search - "c to hex"
-
Short one, but it really gets me every time:
PLEASE tell me that I am not the only one typing hex-numbers in all caps!!!
I literally can't stand to see them in lowercase!!!
Every code I use with hex numbers in it (primarily ASM and C) I HAVE TO convert them into uppercase!!!
Is it just me and my stupid OCD or are there other ones like me????10 -
So I'm writing some multithreaded shit in C that is supposed to work cross-platform. MingW has Posix threads for Windows, so that saved already half of the platform dependency. The other half was that these threads need to run external programs.
Well, there's system(), right? Uhm yes, but it sucks. It's incredibly slow on Windows, and it looks like you can have only one system() call ongoing at the same time. Which kinda defeats the multithreaded driver. Ok, but there's CreateProcessA(), and that doesn't suck.
Fine, now for Linux. The fork/exec hack is quite ugly, but it works and is even fast. Just never use fork() without immediate exec(). First try under Cygwin... crap I fork bombed my system! What is this shit? Ah I fucked up the path names so that the external executable couldn't be run.
Lesson learnt: put an exit() right after the exec() in the path for child process. Should never be reached, but if it goes there, the exit() at least prevents a fork bomb.
Well yeah, sort of works under Cygwin, but only with up to 3 threads. Beyond that, it seems like fork() at some point gives two processes the same PID, and then shit hangs.
Even slapping a mutex around the fork and releasing it only in the parent process didn't help. Fork in Cygwin is like a fork in the ass. posix_spawn() should work better because it can be mapped more easily to the Windows model, but still no dice.
OK, testing under real Linux. Yeah, no issues with that one! But instead, I get some obscure "free(): invalid size" abort. What the fuck would that even mean?! Checking my free() calls: all fine.
Time to fire up GDB in the terminal! Put a catch on the abort signal, mh got just hex data. Shit I forgot to compile with -O0 and -g. Next try. Backtrace shows the full call trace, back to the originating line in my program - which is fclose() on a file.
Ahhh I remember! Under Linux, fclosing a file that is already closed makes the program crash. So probably I was closing it twice. Checking back.. yeah that's where it was.
Shit runs fast on several cores now!8 -
Oh my, never was i triggered more. Of course i can only speak for my experience. I study software development as focus.
First off, the starting languages and or concepts you learn.
Why the fuck do they start with java and don't even really explain how instances actually work? Of course they don't. Because it would be way too fucken much for a semester to go over garbage collection, Instanciation of stuff, allocation in such an advanced system, etc..
How about starting with something not 50% managed by a vm?
Good ol' C. And now don't tell me thats a rough start. We all know about these subjects or exams where it's all about sorting people out. Who will be able to manage a whole bunch of shit or who should consider something else.
Yo dawg sick idea: how about sorting it via the will to achieve the skill of coding?
Nah but we make the exams around coding (by the fucking way done on paper, what the hell) such a fucking breeze, asking you how to convert hex do dec.
Meanwhile maths will make you cut yourself in a dark corner, after you nearly shot yourself because of some lame-ass business-subject.1 -
!rant
So I decided to collab with a website's maker (who i wont name here) to create something like r/place. (not an exact copy.)
I decided to start by learning their API, and customizing the server later.
I asked the guy for some help, and HOLY SHIT.
Let's start off by this: I had to request a chunk. The response data was in binary. 4 bits meant 1 pixel, so right away, I had to deal with that in my code.
No problem, just decided to use C# instead of JS. (see https://www.devrant.io/rants/547013)
I was finally done after a couple of mental breakdowns, and decided to implement updates.
I needed to use webhooks, and that was completely fine. But when I got "C1FFFF0000CA06" as response (in hex), I seeked some help.
C1 is the operation type: it means that a pixel was updated.
FFFF and 0000 were the chunk coordinates. But remeber: it's a signed integer. Guess what, I had to use Two's compliment. I decided to be a lazy asshole and only check for "00000000" because I was only displaying chunk 0,0.
CA06: This is a weird one. It's 2 bytes, and CA0 contains the X and Y coordinate of the pixel (in the chunk), and 6 contains the new color of the pixel.
I was sent the following code to work with 0xCA06:
color = 0xF & buffer
x = buffer >> 10
y = (buffer >> 4) & 0x3F
So I tried to do it, and it didn't work. I'm not blaming the developer of the server (original dev is reddit) because maybe I screwed up, but which guy will have a night of frustration and debugging?
Me.
P.S.: Dev, if you see this, I'm sorry. This API is way too complicated. I know we need to save bandwith and stuff, but damn.1 -
Does anybody knows a command line tool that convert C file (sample.c) to hex file (sample.hex).
I don't need any GUI tool only command line tool.9