Question

The following code gives me the following errors :

error: request for member ‘name’ in something not a structure or union
error: request for member ‘name’ in something not a structure or union
error: request for member ‘data’ in something not a structure or union
error: request for member ‘next’ in something not a structure or union

How could I fix it ?
Code is :

#define SIZE 5

typedef struct hashTable{
    int data;
    char *name;
    struct hashTable *next;
} table;


int hash_function(int value)
{
    return value % SIZE;
}

int insert(char *inFileName, table ***hashLinked)
{
    FILE *inFile;
    int val = -1;
    char str[30];
    int probe;

    if ((inFile = fopen(inFileName, "r")) == NULL)
    {
        fprintf(stderr,"Error opening input file, %s\n", inFileName);
        return -1;
    }
    while(fscanf(inFile,"%s %d",str,&val) == 2)
    {
        probe = hash_function(val);

        if(hashLinked[probe] == NULL)
        {                             
            **hashLinked[probe] = malloc(sizeof(table));   
            **hashLinked[probe]->name = (char *)malloc((strlen(str) + 1) * sizeof(char*));
            strcpy(**hashLinked[probe]->name,str);

            **hashLinked[probe]->data = val;
            **hashLinked[probe]->next = NULL;
        }                                             
        else
        {   
            table* hashLinkedNode = *hashLinked[probe];
            while(hashLinkedNode->next!=NULL)
            {                           
                hashLinkedNode = hashLinkedNode->next;
            }
            hashLinkedNode->next = malloc(sizeof(table));   
            hashLinkedNode->next->name = (char *)malloc((strlen(str) + 1) * sizeof(char*));
            strcpy(hashLinkedNode->next->name,str);  
            hashLinkedNode->next->data = val;
            hashLinkedNode->next->next = NULL;
        }
    } 
    fclose(inFile);
    return 0;
}


void printList(BookNode *hd)
{   
    for ( ; hd != NULL; hd = hd->next)
    {
        printf("[%s,%d]", hd->name, hd->isbn);
        if (hd->next)
            printf(" -> ");
    }
    printf("\n");
}

void printHashTable(BookNode **temp)
{
    BookNode *tmp = NULL;
    int i;
    for(i=0;i<SIZE;i++)
    {
        tmp = temp[i];
        while(tmp)
        {
            printf("%s %d",tmp->name, tmp->isbn);
            tmp=tmp->next;
        }
    }   
}

int main(int argc, char *argv[])
{
    table **hashLinked[SIZE];
    insert(argv[1],&hashLinked);
    printHashTable(**hashLinked);

    return 0;
}

Answer 1

One problem is that you call insert with something other than the type you declared it with,

table **hashLinked[SIZE];
insert(argv[1],&hashLinked);

hashLinked is an array of pointers to pointers to table, so &hashLinked is a pointer to an array of pointers to pointers to table, but insert is declared to take a pointer to pointer to pointer to table. I’m less than confident that I really figured out what you intended to do, but what seems to be reasonable is that you want fewer levels of indirection. I believe the reason for passing &hashLinked is that you want hashLinked to be modified in insert, but that is already done by passing hashLinked itself, you needn’t pass its address. That would make the passed type compatible with the declared type, since as a function argument, hashLinked becomes a pointer to its first element, a table ***.

Then you use inconsistent indirection counts in insert, and get the precedence of * and -> wrong, which causes the “request for member in something that isn’t a struct or union” errors. **hashLinked[probe]->name is parsed **(hashLinked[probe]->name), so tries to access the name member of a table * and then dereference that twice. With the parameter type table ***, the correct access would be (*hashLinked[probe])->name, get a table ** per hashLinked[probe], dereference that once to get a table * and access its (pointee)member name. However, you check if (hashLinked[probe] == NULL), and if so

**hashLinked[probe] = malloc(sizeof(table));

which is a guaranteed null pointer dereferencing. By the check and the following code, I believe that you actually want to have a parameter type of table **, the hashLinked parameter being an array of linked lists of tables, which makes the code far easier to follow. Filling in a BookNode type and adapting a few variables and parameters, I arrive at

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#define SIZE 5

typedef struct hashTable {
    int data;
    char *name;
    struct hashTable *next;
} table;

typedef struct book {
    int isbn;
    char *name;
    struct book *next;
} BookNode;

int hash_function(int value)
{
    return value % SIZE;
}

int insert(char *inFileName, table **hashLinked)
{
    FILE *inFile;
    int val = -1;
    char str[30];
    int probe;

    if ((inFile = fopen(inFileName, "r")) == NULL)
    {
        fprintf(stderr,"Error opening input file, %s\n", inFileName);
        return -1;
    }
    while(fscanf(inFile,"%s %d",str,&val) == 2)
    {
        probe = hash_function(val);

        if(hashLinked[probe] == NULL)
        {
            hashLinked[probe] = malloc(sizeof(table));
            hashLinked[probe]->name = (char *)malloc((strlen(str) + 1) * sizeof(char*));
            strcpy(hashLinked[probe]->name,str);

            hashLinked[probe]->data = val;
            hashLinked[probe]->next = NULL;
        }
        else
        {
            table* hashLinkedNode = hashLinked[probe];
            while(hashLinkedNode->next!=NULL)
            {
                hashLinkedNode = hashLinkedNode->next;
            }
            hashLinkedNode->next = malloc(sizeof(table));
            hashLinkedNode->next->name = (char *)malloc((strlen(str) + 1) * sizeof(char*));
            strcpy(hashLinkedNode->next->name,str);
            hashLinkedNode->next->data = val;
            hashLinkedNode->next->next = NULL;
        }
    }
    fclose(inFile);
    return 0;
}

void printList(BookNode *hd)
{
    for ( ; hd != NULL; hd = hd->next)
    {
        printf("[%s,%d]", hd->name, hd->isbn);
        if (hd->next)
            printf(" -> ");
    }
    printf("\n");
}

void printHashTable(table **temp)
{
    table *tmp = NULL;
    int i;
    for(i = 0; i < SIZE; i++)
    {
        tmp = temp[i];
        while(tmp)
        {
            printf("%s %d",tmp->name, tmp->data);
            tmp = tmp->next;
        }
    }
}

int main(int argc, char *argv[])
{
    if (argc < 2)
        return -1;
    table *hashLinked[SIZE];
    insert(argv[1],hashLinked);
    printHashTable(hashLinked);
    return 0;
}

which compiles warning-free and looks like it might do what you intended.