"User Input" not working as intended

Okay, I've looked through the FAQ's regarding getchar, most if it is a above my level, and the stuff that isn't does not help me at all.

I've been working on this for the pas 6-7hrs and I'm not getting any closer to the solution than when i first started.

/* The Situation */

After the Patient Number check is complete, the diagnosis portion of the program begins, it is in this part i'm having this biggest problem. When the user inputs "yes" or "yupe", "nope" or "no", my program is suppose to just look at the first character of the string they inputed and determine if the response is a "Y" or "N".

No matter which loop i used, it still doesn't work, I've tried a while, for, do/while, switch. I just don't know what is wrong with it. Anyhow, after typing e.g. "Yes", my program will display this....

Fever ----------
Invalid Entry.
Fever ----------

it is on the second Fever, that i'm allowed to actually make my first input. And when i do make and input, it will do the same thing for the next symptom....

All i want to be able to do, is accept a string or a character as an input to the various types mentioned above, if it doesn't fall into this category, it gives a "Invalid Entry" msg, and restates the " Fever ------" prompt.

I need something. FAQ's and Google just isn't working for me.

Here's my complete code minus comments and beautification

Code:

---




 

  printf("\nWhich of the following symptoms does the patient have (Y for yes, N for no)\n");

/*********************************************************/
  /* Fever Input Response */

  do
  {
    printf("\n    Fever -------- ");
    getchar();
    fever_rep = toupper(getchar());
   

    switch(fever_rep)
      {
      case('Y') : fever = 1;
                  fCount = 1;
                  symptoms = symptoms + 1;
                  break;
      case('N') : fever = 0;
                  fCount = 1;
                  break;
        default : printf("\n  Invalid Response\n");
                  break;
      }
  } while(fCount == 0);


/********************************************************/
  /* Headache Input Response */

  do
  {
    printf("\n    Headache -------- ");
    getchar();
    headache_rep = toupper(getchar());
   

    switch(headache_rep)
      {
      case('Y') : headache = 1;
                  hCount = 1;
                  symptoms = symptoms + 1;
                  break;
      case('N') : headache = 0;
                  hCount = 1;
                  break;
        default : printf("\n  Invalid Response\n");
                  break;
      }
  } while(hCount == 0);


/**********************************************************/

---

getchar() returns the next available key from the keyboard buffer. If the keyboard buffer is empty, then it will wait for you to type something and press <Enter> key. So, if you type "Yes" <Enter> then each time getchar() is called it will return the next key in the sequence, or 4 different keys in that example. And your program must get all the keys from the keyboard buffer before attempting to get more input.

You can accomplish that in a couple ways -- the simplest way is by using fgets() which will get all the keys at one time up to and including the '\n' (same as <Enter>) fgets() will also correctly handle the backspace key.

Code:

---

// buffer to hold keyboard input
char input[20];
// get all the keys
fgets(input, sizeof(input), stdin);
// convert first character to upper-case
input[0] = toupper(input[0])
// check for 'Y' or 'N'
if(input[0] == 'Y' || input[0] == 'N')
{
  // do something
}

---

or if you want to get the keys one at a time -- code below will not correctly handle the backspace key.

Code:

---

// buffer to hold keyboard input
char input[20] = {0};
int index = 0, c;
// get all the keys
while(index < (sizeof(input)-1) &&  (c = getchar()) != '\n')
  input[index++] = c;
// convert first character to upper-case
input[0] = toupper(input[0])
// check for 'Y' or 'N'
if(input[0] == 'Y' || input[0] == 'N')
{
  // do something
}

---

I have to use getchar(c) or getc(stdin), i'm still having problems with typing in a string of characters, i did modify all my loops to (do/while)/Switch, and i've compensated for the initial "Invalid Response" but i'm still at a loss as to why my Loop won't handle the string of characters, with the example of 'yes' or 'nnnn'.

If i use 'yes' i'll get this response

Fever ---------- yes
Headache ----
invalid response
Headache ----
invalid response
Headache ---- <------ Where cursor is now


if i use 'nnnn', I'll get this response

Fever ---------- nnnn
Headache ----
Cough --------
Sore Throat --
Sniffles -------- <-------- Where cursor is now


I don't know what the deal is with my code, is help is greatly appreciated.... I'm a noob, so no advanced stuff.

The Code

Code:

---





  printf("\nWhich of the following symptoms does the patient have (Y for yes, N for no)\n");

/*********************************************************/
  /* Fever Input Response */

  do
  {
    printf("\n    Fever -------- ");
    getchar();
    fever_rep = toupper(getchar());
   

    switch(fever_rep)
      {
      case('Y') : fever = 1;
                  fCount = 1;
                  symptoms = symptoms + 1;
                  break;
      case('N') : fever = 0;
                  fCount = 1;
                  break;
        default : printf("\n  Invalid Response\n");
                  break;
      }
  } while(fCount == 0);


/********************************************************/
  /* Headache Input Response */

  do
  {
    printf("\n    Headache -------- ");
    getchar();
    headache_rep = toupper(getchar());
   

    switch(headache_rep)
      {
      case('Y') : headache = 1;
                  hCount = 1;
                  symptoms = symptoms + 1;
                  break;
      case('N') : headache = 0;
                  hCount = 1;
                  break;
        default : printf("\n  Invalid Response\n");
                  break;
      }
  } while(hCount == 0);


/**********************************************************/

---

FAQ > How do I... (Level 2) > Flush the input buffer