keyboard_ascii_codes_with_kbhit()_v1.c

/*

    keyboard_ascii_codes_with_kbhit()_v1.c

    While no key is pressed, it reports that no key is pressed.

    When a key is pressed, it displays its ASCII code.

    Also try function keys and key combinations
    with Shift, Control and Alt keys.


    Note that we use new functions _getch() and _kbhit()
    instead of old functions        getch() and   kbhit ().

    _kbhit()

    https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/kbhit?view=vs-2019

    _getch()

    https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/getch-getwch?view=vs-2019


    You can find all my C programs at Dragan Milicev's pastebin:

        https://pastebin.com/u/dmilicev

        https://www.facebook.com/dmilicev

*/


#include <stdio.h>
#include <conio.h>              // for kbhit()
#include <time.h>               // for clock()

#define WAIT_TIME 100


// wait (do nothing) for time in milliseconds ( 1000 for 1 second )
void wait(int milliseconds)
{
    clock_t start_time = clock();   // get start time

    // looping (do nothing) till required time is not acheived, ; means do nothing
    while ( clock() < start_time + milliseconds );
}


int main(void)
{
    int i = 0, ch;              // ch is pressed key that we will analyze
    int end = 0;                // = 0 because it's not the end of the program yet

    while(!end)
    {
        while( !_kbhit() )      // rotates in that loop until some key is pressed
        {
            if( i<100 )         // we only show i that something would happen
                i++;            // on the screen while no key was pressed
            else
                i=0;

            printf("\n No key was pressed. i = %d \n", i );

            wait(WAIT_TIME);
        }

        ch = _getch();              // Now a key is pressed and we read it.

        switch( ch ) {              // We analyze which key is pressed:

            case 27 :               // ESC for end of program
                    printf("\n Pressed is ESCAPE key to end program \t\t %d \t %c \n", ch, ch);
                    end = 1;        // to end program
                    break;

            case  0 :               // if a function key with a leading 0 is pressed
                    ch = _getch();  // let's empty that 0 and show which key is pressed
                    printf("\n Pressed is function key with a leading   0 \t %d \t %c \n", ch, ch);
                    break;

            case 224 :              // if a function key with a leading 224 is pressed
                    ch = _getch();  // let's empty that 224 and show which key is pressed
                    printf("\n Pressed is function key with a leading   224 \t %d \t %c \n", ch, ch);
                                break;
            default :               // show all other pressed keys
                    printf("\n Pressed is key \t\t %d \t %c \n", ch, ch);
                    break;
        } // switch( ch )

        wait(20*WAIT_TIME);         // pause for better view

    } // while(!end)

    return 0;
}