Function problem

I used scanf in the main function to scan a character, I put the scanf in a while loop, while keyboard input it being scanned I want the other functions to operate, but I can't figure out how to get it to run properly.

Code:

---

//TENNIS
#include <stdio.h>

#define PRINT 0
#define GAME_A 1
#define GAME_B 2
#define DEUCE 3
#define AD_SERVER 4
#define AD_RECEIVER 5

int scoreA = 0;
int scoreB = 0;

int scoreFunct(char c);
void printFunct(int scoreA, int scoreB, char c);

int main (int argc, char **argv){

  char c;
  char team;
 
  printf ("Team A or Team B serves first?: ");
  scanf ("%c", &team);
  printf ("Team %c to serve\n", team);
 
  while(scanf("%c", &c) == 1){

  } 
 
  return(0);
}

int scoreFunct(char c){
 
    while((scoreA < 3) && (scoreB < 3)){
    if(c == 'A'){
      scoreA+=1;
    }
    else if (c == 'B'){
      scoreB+=1;
    }
    else if (c == 'S'){
      return(PRINT);
    }
  }
 
  return(0);
}

void printFunct(int scoreA, int scoreB, char c){
 
  if(scoreFunct(c) == PRINT){
    printf("%d-%d", scoreA, scoreB);
  }
}

---

The ones in red are what I'm stuck on, i want that function to execute while the scanf is running in the main function. I tried getchar, that gives me worse problems.

Thanks in advance

Does this help?


//unsigned char fgetc(FILE* stream);

while (c = (char)fgetc(stdin) != NULL) // while there is input


Not sure if this is what you want but:

Code:

---

while (c = fgetc(stdin) != NULL) {
  scoreFunc(c);
}

---

But you could also replace fgetc(stdin) with getchar(). Also I hope you'll do some error checking cause your program is awfully brittle.

Interesting, but I have no idea what that means, so I'm not going to try to use that :P

Thanks anyways.

I just did:

Code:

---

while(scanf("%c", &c) == 1){

scoreFunct(c);
 
}

---

to call the function, but then when I run it, and it gets to that bit, I can't enter anything, so I guess the while loop is doing something random.

Hmm, I think I solved it, I put the scanf in the other function, and just used scoreFunct(c); to call the function in the main function, without any loops. That seemed to do the trick, but now other problems :S

Programming...

You check the return value of [f]getc() and getchar() against EOF for failure, not NULL. And parentheses are a good idea around code like that.

Code:

---

unsigned char fgetc(FILE* stream);

---

It's int. You can't store EOF in a char, so don't even try.

Quote:

---

I used scanf in the main function to scan a character, I put the scanf in a while loop, while keyboard input it being scanned I want the other functions to operate, but I can't figure out how to get it to run properly.

---

So you want your program to do other things while it's waiting for the user to press a key?

There's no standard way to do that, but you'll find mention in the FAQ of kbhit() and getch() which might do the trick. I believe that both of those functions work with Dev-C++.

Code:

---

#include <conio.h>

int c = 0;

do {
    if(kbhit()) {
        c = getch();
        printf("Received a key press: &#37;c\n", c);
    }

    puts("Processing...");
} while(c != 27);  /* 27, or 0x1B, is the code for ESCAPE */

---

Quote:

---

Originally Posted by dwks

You check the return value of [f]getc() and getchar() against EOF for failure, not NULL. And parentheses are a good idea around code like that.

Code:

---

unsigned char fgetc(FILE* stream);

---

It's int. You can't store EOF in a char, so don't even try.


So you want your program to do other things while it's waiting for the user to press a key?

There's no standard way to do that, but you'll find mention in the FAQ of kbhit() and getch() which might do the trick. I believe that both of those functions work with Dev-C++.

Code:

---

#include <conio.h>

int c = 0;

do {
    if(kbhit()) {
        c = getch();
        printf("Received a key press: %c\n", c);
    }

    puts("Processing...");
} while(c != 27);  /* 27, or 0x1B, is the code for ESCAPE */

---

---

Haha what is all that, never even seen some of that code before, I can't use code I've not learnt in this assignment, but eitherways, I just put the scanning in the second function, so I pretty much figured it out, thanks anyways

Yes i'm sorry I completely bombed it. My suggestion was wrong altogether. I'm new to c, but another thing that was messing me up is you have an infinite loop in your scorefunct if the characters dont match A B or S.

The correct way to get a character read from stdin is:

Code:

---

do {
  c = getchar();
} while (c != 'x');

---

in this case x would exit the loop. scanf() is a poor function to use so get used to fgetc or getchar() (which is the same as fgetc(stdin) for character input.

I wish I knew the criteria for your program so I could help more, as it is your program does nothing. I had to do a lot of assuming just to get it to do anything...

Also look into <ctype.h> for the functions tolower(char) and toupper(char); they help in comparing user input cause you only have to test one case instead of both upper and lower cases....

Just like [f]getc(), it's tolower(int) and toupper(int), although only CHAR_BITS (usually 8, from <limits.h>) of the int are used . . .

Most standard C functions that deal with single characters use ints, not chars. This is probably to handle EOF.