segmentation fault

Does anyone know why i get a segmentation fault when i call scanf() in guessSquare
function im not sure whether im calling it correctly?

Code:

---

int main(void)
{
  /* Stores all hidden data about the minefield. */
  char minefield[MAX_GRID][MAX_GRID];
  /* A version of the minefield that only stores known information. */
  char displayGrid[MAX_GRID][MAX_GRID];
  int display;
  char *rSquare;
  unsigned *cSquare;
    /* Number of cells in each row and column used. */
  unsigned size = 0;
  char inputType;
  /* call functions according to the flow chart diagram*/
  init(minefield, displayGrid);
  size = getSize();
  placeMines(minefield,size);
  displayMinefield(displayGrid,size);
  inputType = guessType();
  guessSquare(rSquare, cSquare, size);
 
  return EXIT_SUCCESS;

/*************************************************/
  void guessSquare(char* row, unsigned* col, unsigned size)
{
    int valid =0;
    char *r = row;
    unsigned *c = col;
 
  do
  {
        valid = 0;
 
        fscanf(stdin, "%c, %u", r, c);
       
        if(*row == 'a')
        {
          valid = 1;
        }
        else if(*row == 'b')
        {
          valid = 1;
        }
        else if(*row == 'c')
        {
          valid = 1;
        }
        else if (*row == 'd')
        {
          valid = 1;
 
        }
        else if(*row == 'e')
        {
          valid = 1;
        }
        else if(*row =='f')
        {
          valid = 1;
        }
        else
        {
            printf("Incorrect row A - F !\n");
            readRestOfLine();
        }
  }while(!valid);
 
}

}

---

You forgot to make your pointers point to anywhere.

where abouts in my main where im passing in the values to the parameters for the function?

Code:

---

char *r = row;
unsigned *c = col;
fscanf(stdin, "%c, %u", r, c);

---

It assigns address of row to r & col to c,if u still want to make scanf work then ommit those two assignments.Try using

Code:

---

fscanf(stdin, "%c, %u", row, col);

---

instead.

Thanks & regards
Vinit :)

i still get a seg fault in my code

> It assigns address of row to r & col to c,if u still want to make scanf work then ommit those two assignments
Simply copying a pointer to an undefined location doesn't make it a defined pointer.

In main, you need
char rSquare;
unsigned cSquare;
guessSquare(&rSquare, &cSquare, size);

i got rid of the seg fault now for some reason fscanf isnt taking the value properly because it wont evaluate the if statements properly it keeps printing error even though i type in the correct input

Code:

---

void guessSquare(char* row, unsigned* col, unsigned size)
{
  int valid =0;
  char r;
  unsigned c;
 
  r = *row;
  c = *col;
 
  printf("Enter a square from row A -F and Col 1-6\n") ;
  do
  {
        valid = 0;
 
        fscanf(stdin, "%c, %u", &r, &c);
         
         
        if(r == 'a')
        {
          valid = 1;
        }
        else if(r == 'b')
        {
          valid = 1;
        }
        else if(r == 'c')
        {
          valid = 1;
        }
        else if (r == 'd')
        {
          valid = 1;
 
        }
        else if(r == 'e')
        {
          valid = 1;
        }
        else if(r =='f')
        {
          valid = 1;
        }
        else
        {
            printf("error\n");
            break;
        }
  }while(!valid);
 
}

---

Don't use scanf / fscanf perhaps?

I dunno - why don't you check the return result of functions?

Using anything other than fgets() to read input is basically a waste of time IMO. It simply leads to more problems, and there's the whole "get rid of surplus newlines problem" - ick ick ick....

Here,

Code:

---

#include <stdio.h>
#include <stdlib.h>

void guessSquare(char *row, unsigned int *col, unsigned size);

int main(void)
{
  char rSquare;
  unsigned int cSquare;
  unsigned int size = 0;
  guessSquare( &rSquare, &cSquare, size);
  printf( "%c %u\n", rSquare, cSquare );
  return EXIT_SUCCESS;
}

/*************************************************/
void guessSquare(char *row, unsigned *col, unsigned size)
{
  char buff[BUFSIZ];
  int valid = 0;

  while ( !valid &&
          fgets( buff, sizeof buff, stdin ) != NULL ) {
    if ( sscanf( buff, "%c, %u", row, col ) == 2 ) {
      if ( *row >= 'a' && *row <= 'f' ) {
        valid = 1;
      }
    }
  }
}

---

ok iv tried that but why does it keep asking for input after i press enter

I've no idea - perhaps you didn't enter the required input - say check the caps lock key.

Do you have a log of the input and output ?

Try putting some additional code in - say some printf statements in the else part of each of those if statements.