Getting an input from the user without having to wait - C language..!

Question

I'm currently programming a simple timer, which runs from 00s to 55s and then start from 00 again and keeps counting until the user stops it. For that purpose I made two options for the user: 1. start & 2. reset. Choosing number one runs the program, and choosing number two, as I its supposed, will turn the timer in to 00s and keep it there.

Now the problem I'm facing is that I want to get an input from the user without stopping the timer (i.e. enabling the user to enter 2 at anytime while the program is running so he can stop the ongoing counting). I tried to use functions like getch() and scanf(), but they're stopping the timer, which is entirely ruining the program.

Any help appreciated guys..!!

What you need is working with threads. See: http://www.cs.cf.ac.uk/Dave/C/node29.html — WeezHard, Sep 16 '15 at 11:56
There are no timers in standard C. Therefore, all answers will be system-specific, so you need to specify which system and compiler you are using. — Lundin, Sep 16 '15 at 13:31
http://stackoverflow.com/questions/448944/c-non-blocking-keyboard-input — abelenky, Sep 16 '15 at 15:07

user3121023 · Accepted Answer · 2015-09-16T15:28:32.990

You can use ncurses to accomplish this. On Windows, something similar could be done with kbhit() and getch()

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/time.h>
#include <time.h>
#include <ncurses.h>

int main()
{
    char ch = 0;
    int row = 0;
    int line = 0;
    int col = 0;
    int counting = 1;
    char text[80] = {""};
    long int elapsed = 0;
    struct timeval start;
    struct timeval stop;

    initscr ( );
    noecho ( );
    timeout(100);
    getmaxyx ( stdscr, row, col);
    line = row / 2;
    snprintf ( text, sizeof ( text), "press 1 to exit or 2 to reset");
    mvprintw ( line - 1, ( col - strlen ( text)) / 2,"%s", text);
    gettimeofday ( &start, NULL);
    while ( 1) {
        if ( counting) {
            gettimeofday ( &stop, NULL);

            elapsed = (stop.tv_sec - start.tv_sec);

            snprintf ( text, sizeof ( text), "         %ld         ", elapsed);
            mvprintw ( line, ( col - strlen ( text)) / 2,"%s", text);
            if ( elapsed > 54) {
                gettimeofday ( &start, NULL);
            }
        }
        else {
            snprintf ( text, sizeof ( text), "paused press 1 or 2");
            mvprintw ( line, ( col - strlen ( text)) / 2,"%s", text);
        }
        //refresh ( );
        if ( ( ch = getch ( )) == '1' || ch == '2') {
            if ( ch == '2') {
                counting = !counting;
                if ( counting) {
                    gettimeofday ( &start, NULL);
                }
            }
            if ( ch == '1') {
                break;
            }
        }
    }
    endwin ( );
    return 0;
}

Getting an input from the user without having to wait - C language..!

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