[File: double/double.c]
#include <stdio.h>
char  line[100];   /* input line from console */
int   value;      /* a value to double */
int main()
{
                                  
                                                 
  printf("Enter a value: ");
  fgets(line, sizeof(line), stdin);
  sscanf(line, "%d", &value);
  printf("Twice %d is %d\n", value, value * 2);
  return (0);
}