Input numbers without using Enter [c]

Question

How input the number of digits without using Enter I can do it with Enter:

scanf("%4d",&num);

So how I can do that without press Enter?

[`man 3 scanf`](http://linux.die.net/man/3/scanf) should help. — chrk, Jan 07 '16 at 15:28
Never mind,the question of how input the number of digits without using Enter? — AngeleStar, Jan 07 '16 at 15:38
you can not, you have to deal with getch() or something like, (nb: getch() is not standard c). — milevyo, Jan 07 '16 at 15:42
If code runs in a hosted environment, redirect input like with `program < input.txt`. — chux - Reinstate Monica, Jan 07 '16 at 18:13

score 1 · Answer 1 · edited May 23 '17 at 12:15

1

To avoid the need to hit enter you need to disable icanon mode using the ioctl system call (or stty command - assuming you are using Linux). You probably want to use getchar instead of scanf and do your own input processing. It is very difficult.

You can maybe look at this post:

How to avoid press enter with any getchar()

edited May 23 '17 at 12:15

Community

1
1

answered Jan 07 '16 at 15:58

rghome

8,529
8
43
62

score 0 · Answer 2 · answered Jan 07 '16 at 16:21

as i said in comment above and as a reply to @Rabbid76

getch() and putch() are non-standard functions defined in conio.h, mostly used in turbo C/dev C++ environement. getchar() are putchar() are standard functions defined in C standard and they can be used in all environments. Yes, you can certainly write a program without these 4 functions from google

but if some one insists here is how it can be (not handling negative numbers and backspace)

int inputDgits(int nb){
   int i=0;
   int j=0;
   char tmp;


   for( j=0; j < nb; ){
      tmp=getch();
      if (tmp>='0' && tmp<='9'){
          i *= 10;
          i += tmp-'0';
          j++;
          printf("%c",tmp);
      }else{
         // beep;
      }
   }
   return i;
}

score -1 · Answer 3 · edited Mar 12 '18 at 13:07

-1

Thank you,but I mean to his:

int i = 0;
for (i=0;i<4;i++)
{
    getche();
}

edited Mar 12 '18 at 13:07

Rabbid76

202,892
27
131
174

answered Jan 07 '16 at 16:12

AngeleStar

29
6

Input numbers without using Enter [c]

3 Answers3