C dynamic array of structures, no errors, program terminates when ran - c

Question

When ran, the program immediately terminates from an issue I believe to be associated with memory allocation. The main function only calls this function and another to delete the memory allocated
DrinkMachine *create(void){
FILE *inFile;
//Pointer to data structure
DrinkMachine *drinkMachine;
// Memory allocation
drinkMachine = calloc(1, sizeof(DrinkMachine));
if(drinkMachine == NULL) // Check success
return NULL;
// Open the input file for reading
inFile = fopen("drink_machine.txt" , "r");
if(!inFile){
puts("Error opening file");
return NULL;
}
// Read drink count from file
fscanf(inFile, "%d", &(drinkMachine->numItems));
printf("DEBUG read file arrayLen: %d\n", drinkMachine->numItems);
// Dynamically create array of drink item structures
drinkMachine->drinkItem = malloc(drinkMachine->numItems*sizeof(DrinkItem));
if(drinkMachine->drinkItem == NULL){
puts("ERROR: Failed to allocate memory");
return NULL;
}
// Put information from file into drinkItem structs
for(int i=0; i < drinkMachine->numItems; ++i){
fscanf(inFile, "%s %lf %d", (drinkMachine->drinkItem[i].name), &(drinkMachine->drinkItem[i].price), &(drinkMachine->drinkItem[i].drinkLeft));
printf("DEBUG drink %d is: %s %lf %d\n", i, (drinkMachine->drinkItem[i].name), (drinkMachine->drinkItem[i].price), (drinkMachine->drinkItem[i].drinkLeft));
}
// Close inFile
fclose(inFile);
// Force output to screen
puts("DEBUG readFile Success!");
fflush(stdout);
return drinkMachine;
}
The program ran into errors or wouldn't properly allocate memory and would successfully output the error message when ran, until I put in the line:
drinkMachine->drinkItem = malloc(drinkMachine->numItems*sizeof(DrinkItem));
At this point the program compiles without warning or errors, but terminates immediately when ran without any output. In case it helps, here are the structures:
typedef struct _DrinkItem{
int id;
char *name;
double price;
int drinkLeft;
int drinkSold;
} DrinkItem;
typedef struct _DrinkMachine{
int version;
int numItems;
int drinkLocation;
DrinkItem *drinkItem;
} DrinkMachine;

Answer 1

You have to allocate storage for each name too. You are reading characters into an unallocated pointer on line 30. You should read the name into a temporary array, get the name’s length, allocate (length+1) bytes of storage to name, and strncpy the data over.

Answer 2

You didn't allocate name space, you didn't handle any input error, you use int without verify that it not negative for a size, you didn't use stderr for error, you used reserved identifier and more.
Here a proposition of code, that I think fix all your errors (didn't test it as you didn't give example of input and output):
#include <stdio.h>
#include <stdlib.h>
typedef struct DrinkItem {
int id;
char *name;
double price;
int drinkLeft;
int drinkSold;
} DrinkItem;
typedef struct DrinkItem {
int version;
size_t numItems;
int drinkLocation;
DrinkItem *drinkItems;
} DrinkMachine;
static void helper_free(DrinkItem *drinkItems, size_t n) {
for (size_t i = 0; i < n; i++) {
free(drinkItems[i].name);
}
free(drinkItems);
}
DrinkMachine *create(char const *path) {
FILE *inFile = fopen(path, "r");
if (!inFile) {
fprintf(stderr, "Error opening file");
return NULL;
}
size_t numItems;
if (fscanf(inFile, "%zu", &numItems) != 1) {
fprintf(stderr, "Error parsing\n");
return NULL;
}
#ifndef NDEBUG
printf("DEBUG read file arrayLen: %zu\n", numItems);
#endif
DrinkItem *drinkItems = malloc(numItems * sizeof *drinkItems);
if (!drinkItems) {
fprintf(stderr, "ERROR: Failed to allocate memory");
return NULL;
}
for (size_t i = 0; i < numItems; ++i) {
char *name = malloc(100);
if (!name) {
helper_free(drinkItems, i);
fprintf(stderr, "ERROR: Failed to allocate memory");
return NULL;
}
double price;
int drinkLeft;
if (fscanf(inFile, "%99s %lf %d", name, &price, &drinkLeft) != 3) {
free(name);
helper_free(drinkItems, i);
fprintf(stderr, "Error parsing\n");
return NULL;
}
drinkItems[i] =
(DrinkItem){.name = name, .price = price, .drinkLeft = drinkLeft};
#ifndef NDEBUG
printf("DEBUG drink %zu is: %s %lf %d\n", i, name, price, drinkLeft);
#endif
}
fclose(inFile);
DrinkMachine *drinkMachine = malloc(sizeof *drinkMachine);
if (!drinkMachine) {
helper_free(drinkItems, numItems);
fprintf(stderr, "ERROR: Failed to allocate memory");
return NULL;
}
*drinkMachine =
(DrinkMachine){.drinkItems = drinkItems, .numItems = numItems};
#ifndef NDEBUG
puts("DEBUG readFile Success!\n");
#endif
return drinkMachine;
}