A millisecond Timer in C

Here is one possible implementation of a millisecond timer in C using time.h and ts.tv_nsec
Proof of concept:  Timer Source code

A simpler, more compliant version can be found in repository.
#include <stdio.h> #include <stdlib.h> #include <time.h> typedef struct nTimer{ int ms; //milliseconds long oldtime; //to calculate increment in time long oldticks; //to calculate increment in no. of ticks long ticks; //how many ticks have been made long elapsed; //total time elapsed in ms } NTIMER; /* Miliseconds timer */ int timer1(NTIMER *mytimer1){ struct timespec ts; long get_ms; long res, res2; if (mytimer1->ticks == 0){ //First tick, set up values mytimer1->oldtime = 0; mytimer1->ticks = 1; mytimer1->oldticks = 1; mytimer1->elapsed = 0; return 1; } else{ //subsequent ticks timespec_get(&ts, TIME_UTC); //Getms gets 10^-3 milleseconds get_ms = (ts.tv_nsec % 10000000) / 1000000; //Add a millisecond every time a change is detected in 10^-3 res = get_ms-mytimer1->oldtime; if(abs(res) >= 1){ mytimer1->elapsed = mytimer1->elapsed + 1; mytimer1->oldtime = get_ms; } //Calculate tick by divided time elapsed with ms requested res2 = mytimer1->elapsed / mytimer1->ms; if (res2 == mytimer1->oldticks) { mytimer1->ticks = mytimer1->ticks + 1; mytimer1->oldticks = mytimer1->oldticks+1; return 1; } else return 0; } } int main(){ NTIMER mytimer1; int i=0; char msg[13] = "Hello there!\0"; /* INIT TIMER */ //mytimer1.ticks must be set to 0 at start. mytimer1.ms = 30; mytimer1.ticks = 0; do{ if (timer1(&mytimer1) == 1) { printf("%c\n", msg[i]); i++; } } while (mytimer1.ticks < 13); printf("Total elapsed time in ms: %ld", mytimer1.elapsed); }

Google Sheets & Javascript

GOOGLE SHEET MANIPULATION

Spreadsheet link

WORD TRANSLATION
COMMENT
[+] Words:

>> Translation:

Result:

Table:

A one-line formula to add the digits of a 2-digit number using mod

Adding two digits of a number is the same as subtracting 9 multiplied by the number in the tens from the original number. This formula uses mod(%) to isolate such number and provides the result of the addition of the 2 digits of a given number from 11 to 99:

From: x- (((x -(x mod 10)) / 10) *9)
To: f(x) = x - (1/10(x - x mod 10))× 9

Example: 23 -> 2+3 = 5 | 23 - (9*2) = 5 | 23 - (((23 - (23 mod 10)) / 10) * 9) = 5 

Sample in C: twodigits

Asteroid Game

Screenshot of the remake of the classic game Asteroid with SDL2 in pure C.

[+] Code:

First commit and subsequent development: 

https://github.com/velorek1/asteroid

[+] Game Structure:

One version of kbhit() using windows API

Here is one version of kbhit() using windows API (GetAsyncKeyState). It runs through 255 possible key scancodes in pulses. If a key is pressed, it returns 1 and the value of the key pressed by reference.
This can be used to make a rudimentary keylogger in Windows.
Proof of concept:  Keylogger Source code

#include <windows.h>

Prototype: int kbhit(char *ch); 

Call:

int keypressed=0;

char ch=0;

keypressed = kbhit(&ch);

#include <stdio.h> #include <stdio.h> #include <windows.h> #define KEYPRESSED -32768 #define LIMITSCANCODE 255 int kbhit(char *ch){ int i=0, keystate=0; int exitFlag=0, ok=0; char oldch=0; oldch = *ch; //Run through all key scancodes from 0 to 255 do{ keystate = GetAsyncKeyState(i); if (keystate == KEYPRESSED) { //A key has been pressed exitFlag = 1; ok=1; } if (i == LIMITSCANCODE) { //Exit if we got to the end exitFlag = 1; ok=0; } if (keystate == 0) i++; } while(exitFlag != 1); //return key pressed *ch = i; if (*ch == oldch) { //Reset if we have the same value as before. ok = 0; } return ok; } int main(){ int keypressed; char ch; printf("Scanning Key codes... Press ESC to exit.\n"); keypressed = 0; do{ keypressed = kbhit(&ch); if (keypressed == 1) { printf("Keyint: %d | Ascii %c | Keypressed: %i\n",ch, ch,keypressed); keypressed=0; } } while(ch!=27); return 0; }

Listing files recursively in C in a menu with scroll.

One of the most complex programs I've ever written which makes use of my latest development with list boxes in C. You can navigate and change path while the different files and directories in the new path are added to the dynamic list for scroll.

>> SOURCE CODE <<

Segmentation Fault - C Pointers

Segmentation Fault!!!

I have seen this phrase so many times I may end up having nightmares with it. But I got there in the end!! In my experience,  it seems the only way to learn how to use pointers properly is through trial and error. :D

This time I've used them to develop a ListBox in C with scroll capabilities.

As usual you can find it in my github repository. (Code available for Linux, Windows and DOS).

Cheers!

Demo: