C program crashes when trying to refer to struct array - c

Question

I'm trying to make a simple database program, but when I get to this line
int idSearch(product* itens, int id) {
int i = 0;
for(i; i < size; i++) {
if(itens[i].id == id) //<=== This line
return i;
}
return ITEM_NOT_FOUND;
}
the program stops responding.
size is set as a global variable in the begining of the program
FILE* flog;
FILE* db;
FILE* sizef;
int size = 100;
this function is called by
void newProduct(product* itens, char name[64], int id, float price) {
int pos = idSearch(itens, 0);
if(idSearch(itens, id) != ITEM_NOT_FOUND) {
printf("Erro, o produto ja existe");
return;
}...
items is defined as
itens = (product*) calloc(sizeof(product), size);
and product is a struct defined as such
typedef struct{
char name[64];
int id;
float price;
int amount;
} product;
Firstly I thought the problem was that I was not using the -> operator, but when I tried the compiler says its not right.
I'm using Code::Blocks with GCC compiler on a Windows 7 x64
**EDIT: the whole code can be found here: http://hastebin.com/atulajubar.tex
Hope to hear answers soon, Thanks in advance

Answer 1

**EDIT: You're calling calloc() wrong. The signature is: void *calloc(size_t nelem, size_t elsize);
You're giving it the size first, then the number of elements. Switch that around and see if your problem is resolved.
Also, when calling (AFTER THE FIX:) itens = (product*) calloc( size, sizeof(product) );,
it's important to check to see that itens is not NULL after doing this. If calloc isn't able to give you back the right amount of memory, it returns a NULL pointer I believe. Check this, because if you're getting NULL back, that's your issue.
One good, easy, portable way of checking that would be:
if(!itens){
fprintf(stderr, "Error! Could not allocate memory!\n");
exit(1);
}
Also, as WhozCraig suggested, please make sure your code contains #include <stdlib.h>, a requirement of calloc() as per its man page.

Answer 2

This is wrong:
if((db = fopen(DB_PATH, RB))==NULL)
{
if((db = fopen(DB_PATH, RWB))==NULL)
{
exit(1);
}
else
{
itens = (product*) calloc(sizeof(product), size);
fwrite(itens, sizeof(product), size, db);
rewind(db);
}
}
fread(itens, sizeof(product), size, db);
If you have a DB_PATH file in the current working directory the first fopen() will succeed and the items allocation will never take place. Only if the file is not found, but is then successfully created will items contain a valid allocation, assuming calloc worked.
That else condition should be removed:
// note calloc parameter order addressed.
itens = calloc(size, sizeof(product));
if (itens == NULL)
{
perror("Failed to allocate items.");
exit(EXIT_FAILURE);
}
if((db = fopen(DB_PATH, RB))==NULL)
{
if((db = fopen(DB_PATH, RWB))==NULL)
exit(EXIT_FAILURE);
fwrite(itens, sizeof(product), size, db);
rewind(db);
}
fread(itens, sizeof(product), size, db);
There is a significant amount of error checking left to handle, but this needs to be addressed regardless.