Thread: How to specify inputs using scanf in a particular format

In a format string, each character stands for itself, apart from %

So

Code:

scanf("%d:{(%d,%d)}", &r, &x, &y );

You really need to do better than bouncing back "It doesn't work".

Of course if works!

Code:

$ cat foo.c
#include<stdio.h>
int main ( int argc, char *argv[] ) {
    char message[] = "4:{(1,2)}";
    int x, y, r;
    if ( sscanf( message, "%d:{(%d,%d)}", &r, &x, &y) == 3 ) {
      printf("Qapla'!: %s parsed out %d %d %d\n", message, r, x, y);
    } else {
      printf("You have dishonoured the ways of C\n");
    }
    return 0;
}

$ gcc -Wall foo.c
$ ./a.out 
Qapla'!: 4:{(1,2)} parsed out 4 1 2

Now, YOU post what you actually tried, and what you actually typed in, and so on.

Actually i want user to provide the input.

Code:

printf("\nEnter the radius:");
scanf("%d",&r);
printf("\nEnter the coordinates of the center:");
scanf("%d%d",%x,%y);

Instead of this, i want user to enter like this:

Code:

printf("\nEnter the radius and the coordinates of the center: [r:{(x,y)}]
scanf(......);

what should i write in the scanf() so that the user on running the program, see the screen like this:

Code:

Enter the radius and the coordinates of the center: [r:{(x,y)}]
4:{(1,2)}      // user enters only 4,1,2. not :,{,(,),}

but i dont know how to do this. can u plz help me with this?

If you want that level of cursor and display control, then you're going to have to use something like ncurses, or some other terminal control library for your OS/Compiler.

Standard ISO-C doesn't have anything which can do what you ask.

If you're still learning, you're making this needlessly complicated.

This thread is a good example of why people hate scanf. Why do they hate it? Because they can't decide what format they really want, and they expect it to be some magical function that translates whatever random thing they decide to type at any given moment into what they really meant.


Quzah.