myio.h

// ============================
// = User Input Function in C =
// ============================


#include <stdio.h>

//
// The my_string type can be used to represent a "string" in C.
// This needs to be a struct so that it can be returned from
// functions.
//
typedef struct my_string
{
  char str[256]; // my string contains an array of 255 characters + null
} my_string;

//
// Reads a string of up to 255 characters + 1 for null
//
my_string read_string(const char* prompt)
{
  my_string result;
  printf("%s", prompt);
  scanf(" %255[^\n]", result.str );
  return result;
}

//
// Reads a integer from the user.
//
int read_integer(const char* prompt)
{
  my_string line;
  int num;
  char temp; //used to check nothing comes after the int
  
  line = read_string(prompt);
  // scan the string, looking for a number ... followed by nothing
  while ( sscanf(line.str, " %d %c", &num, &temp) != 1 )
  {
    // scan found a number followed by something... so its not a whole number
    printf("Please enter a whole number.\n");
    line = read_string(prompt);
  }
  
  return num;
}