conversion code with int pointers

Question

#include <stdio.h>
#include <ctype.h>

void readFile(FILE *file);
void count (FILE *file, int *alpha, int *digit, int *punct, int *spaces);
void printMessage(int *alpha, int *digit, int *punct, int *spaces);

int main( void ) {
FILE *file = NULL;
readFile(file);
return 0;
}

void readFile(FILE *file) {
file = fopen("/Users/AdmiralDanny/Desktop/testFile.txt", "r");
int *alpha = NULL, *digit = NULL, *punct = NULL, *space = NULL;
if (file) {
  count(file, alpha, digit, punct, space);
  fclose(file);
} else {
  perror( "error opening the file" );
}
}

void count (FILE *file, int *alpha, int *digit, int *punct, int *spaces) {
  int ch;

 while ((ch = fgetc(file)) != EOF ) {
   if (isalpha(ch) != 0) {
  ++alpha;
  } else if (isdigit(ch)) {
  ++digit;
  } else if (ispunct(ch)) {
  ++punct;
  } else if (isspace(ch)) {
    ++spaces;
  }
}
 printMessage(alpha, digit, punct, spaces);
}

void printMessage(int *alpha, int *digit, int *punct, int *spaces) {
printf( "alphabetic characters: %d\n", alpha );
printf( "digit characters: %d\n", digit);
printf( "punctuation characters: %d\n", punct );
printf( "whitespace characters: %d\n", spaces );
}

my .txt file only has 4 spaces and 12 alphabet character, but it gives me 48 alphabetic characters and 8 white space characters? why is this happening? also, i get a warning when i tried to print out the int pointeres in printMessage method

Answer 1

No memory has been allocated for any of the ints and the count() function is just incrementing the int pointers not an int value:

++spaces; /* spaces is an int* so this increments the pointer. */

You could use malloc(), but it would simpler to stack allocate and pass the addresses in.

int alpha = 0, digit = 0, punct = 0, space = 0;
count(file, &alpha, &digit, &punct, &space);

and in count():

(*spaces)++;

dereference the ints for incrementing and dereference for printing:

printf( "whitespace characters: %d\n", *spaces);

As the caller of count() does not require the updated values of the ints, just pass by value and forget about pointers altogether (same for printMessage()).

Answer 2

you can print address what pointer points to:

printf( "alphabetic characters: %p \n", alpha );

if you want just the value:

printf( "alphabetic characters: %d\n", *alpha );

same as *digit, *punct ....