Reading two dimensional array from file and printing it - c

Question

I have some problems with my code. Everything is fine; gcc shows no errors or warnings; valgrind says no memory leaks, but my array isn't printed and I'm not sure why. Is fscanf() not working correctly or am I printing it incorrectly?
#include <stdio.h>
#include <stdlib.h>
int arrsize (FILE *file)
{
if (file == NULL) {
printf("Error: file pointer is null.");
return 0;
}
int sizer;
fscanf(file, "%d", &size);
return size;
}
int main()
{
int i = 0, j = 0, k = 0,a=0;
FILE *fp;
if ((fp = fopen("matrix.txt", "r")) == NULL)
{
printf("Error: file pointer is null.\n");
return 1;
}
int size = arrsize(fp);
printf("Array size is %d x %d \n", size, size);
double **array = (double **)malloc(size * sizeof(double *));
for (i; i < size; i++)
array[i] = (double *)malloc(size * sizeof(double));
for (i; i < size; i++)
{
for (j = 0; j < size; j++)
{
fscanf(fp, " %lf", &array[i][j]);
printf(" %lf ",array[i][j]);
}
}
for (k ; k < size; k++) {
free(array[k]);
}
free(array);
fclose(fp);
return 0;
}

Answer 1

Check the return of fscanf and malloc to make sure of success.
Add fflush ( stdout); to the print loops since the format string does not have a newline.
#include <stdio.h>
#include <stdlib.h>
int arrsize (FILE *file)
{
if (file == NULL) {
printf("Error: file pointer is null.");
return 0;
}
int size;
if ( 1 == fscanf(file, "%d", &size)) {
return size;
}
return -1;
}
int main()
{
int i = 0, j = 0, k = 0;
FILE *fp;
if ((fp = fopen("matrix.txt", "r")) == NULL)
{
printf("Error: file pointer is null.\n");
return 1;
}
int size = arrsize(fp);
if ( -1 == size) {
fprintf( stderr, "Error: problem parsing array size.\n");
return 1;
}
printf("Array size is %d x %d \n", size, size);
double **array = NULL;
if ( NULL != ( array = malloc(size * sizeof(double *)))) {
for (i = 0; i < size; i++) {
if ( NULL == ( array[i] = malloc(size * sizeof(double)))) {
fprintf ( stderr, "problem allocation array[]\n");
while ( i) {
i--;
free ( array[i]);
}
free ( array);
return 1;
}
}
}
else {
fprintf ( stderr, "problem allocation array\n");
return 1;
}
for (i = 0; i < size; i++)
{
for (j = 0; j < size; j++)
{
if ( 1 == fscanf(fp, "%lf", &array[i][j])) {
printf(" %lf ",array[i][j]);
}
else {
fprintf ( stderr, "problem parsing double\n");
break;
}
}
fflush ( stdout);
}
for (k = 0; k < size; k++) {
free(array[k]);
}
free(array);
fclose(fp);
return 0;
}