c programming check if key pressed without stopping program

Question

as you know, when using getch() in windows, the applications waits for you until you press a key,

how can i read a key without freezing the program , example :

void main(){
  char   c;
  while(1){
  printf("hello\n");
  if (c=getch()) {
  .
  .
  .
  }  
}

thank you.

Try `kbhit()` from ``, I believe. And `main()` should return an `int`. — Jonathan Leffler, Nov 25 '12 at 01:40
@Joe: Some of the ones used by people working on Windows asking that question here on SO...A search on SO for `kbhit [c]` turns up 80+ questions. And `getch()` comes from the same header, so it is reasonable to suppose that if they can use `getch()` they can also `kbhit()`. — Jonathan Leffler, Nov 25 '12 at 01:44

score 12 · Accepted Answer · answered Nov 25 '12 at 01:47

12

You can use kbhit() to check if a key is pressed:

#include <stdio.h>
#include <conio.h> /* getch() and kbhit() */

int
main()
{
    char c;

    for(;;){
        printf("hello\n");
        if(kbhit()){
            c = getch();
            printf("%c\n", c);
        }
    }
    return 0;
}

More info here: http://www.programmingsimplified.com/c/conio.h/kbhit

answered Nov 25 '12 at 01:47

emil

1,642
13
12

One should not use conio.h its very old header file and its non standard. – Haseeb Mir Feb 07 '20 at 20:55
1

There is an error in this code, it will print hello indefinitely. – user10191234 Jan 07 '21 at 09:26
@user10191234: same as OP wanted, right? it will print "hello" in a loop and what ever key that is pressed. – emil Jan 22 '23 at 00:14

score 1 · Answer 2 · answered Feb 05 '14 at 18:21

1

I needed similar functionality in a console application in Linux, but Linux don't provide kbhit function. On searching Google, I found an implementation at -

http://www.flipcode.com/archives/_kbhit_for_Linux.shtml

answered Feb 05 '14 at 18:21

Harmeet

556
5
10

c programming check if key pressed without stopping program

2 Answers2

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