c - function for reading lines from file, after few iterations raises an error

Question

i need to make a function which creates a hash table with chaining method, after this error occurred i continued to the next task for now , and while doing a loop to read lines from text file, after 2 or 3 iterations i get an error "Critical error detected c0000374" i can't find any reason for it and i searched the web of course didn't find what was the problem here's my code:

int parseWordsToTable(char* filePath, HashTable* ht) {
    FILE* Dictionary = fopen(filePath, "r");
    for (int Line = 0; Line < 50; Line++) {
        char* line = (char*)malloc(sizeof(char));
        if (line == NULL)
            exit("Not Enough Memory!");
        fgets(line, 15, Dictionary);
        printf("%s", line);
    }
    return 1;
}

sometimes it gets 2 iterations and sometimes 3 , i just don't get it... the breakpoint and the error occur on this line:

char* line = (char*)malloc(sizeof(char));

by the way , the same happens on this code:

HashTable* initTable(int tableSize, int hashFunction) {
    HashTable* Table = (HashTable*)malloc(sizeof(HashTable));
    if (Table == NULL)
        exit("Not Enough Memory!");
    Table->tableSize = tableSize;
    Table->cellsTaken = 0;
    Table->hashFunction = hashFunction;
    Table->numOfElements = 0;
    for (int index = 0; index < tableSize; index++) {
        Table[index].hashTable = (HashTableElement*)malloc(sizeof(HashTableElement));
        if (Table[index].hashTable == NULL)
            exit("Not Enough Memory!");
        Table[index].hashTable->key = index;
        Table[index].hashTable->chain = (LinkedList*)malloc(sizeof(LinkedList));
        if (Table[index].hashTable->chain == NULL)
            exit("Not Enough Memory!");
        Table[index].hashTable->key = 0;
        Table[index].hashTable->chain = NULL;
    }
    return Table;
}

but only on the fourth iteration..

question from:https://stackoverflow.com/questions/65600923/function-for-reading-lines-from-file-after-few-iterations-raises-an-error

Answer 1

You must allocate enough elements. It is bad to lying for fgets() that 15-byte buffer is passed while the buffer is actually only one byte.

Also don't forget to check if fopen() is successful and close the opened file.

int parseWordsToTable(char* filePath, HashTable* ht) {
    FILE* Dictionary = fopen(filePath, "r");
    if (Dictionary == NULL) return 0; /* check if fopen() is successful */
    for (int Line = 0; Line < 50; Line++) {
        char* line = (char*)malloc(15); /* allocate enough elements */
        if (line == NULL)
            exit("Not Enough Memory!");
        fgets(line, 15, Dictionary);
        printf("%s", line);
    }
    fclose(Dictionary); /* close opened file */
    return 1;
}