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; }