Thread: Help on restricting input to a numbers only.

Below is the code I am using so far. Below code no problem but it was too long and less efficient.

Code:

#include <stdio.h>

    int main(void)
    {

        char dummy[50];
        int c_size[1], nFields;

        printf("Input class size (num of students): ", stdout);

            nFields = scanf("%d%1[^\n]", &c_size[0], dummy);

            while(1 != nFields || c_size[0] < 1)
            {
                printf("Invalid class size. Please try again.\n");
                fputs("\nInput class size (num of students): ", stdout);
                fflush(stdout);

                while(0 != scanf("%*[^\n]")); 

                nFields = scanf("%d%1[^\n]", &c_size[0], dummy); 
            }

    }

So, I wonder if anyone got a more good suggestion to restricting input to number only. Thanks you.