Currently doing the pset5, and keep getting seg fault when running Valgrind. This is the error messsage I get:
/etc/profile.d/cli.sh: line 94: 1150 Segmentation fault valgrind ./speller texts/cat.txt
Looks like your program is trying to access areas of memory that it isn't supposed to access. Did you try to change a character in a hardcoded string? Are you accessing an element of an array beyond the size of the array? Are you dereferencing a pointer that you haven't initialized? Are you dereferencing a pointer whose value is NULL? Are you dereferencing a pointer after you've freed it?
Thats what help50 highlights. I cant find whats causing the seg fault. Anny suggestions on what could it be? In theory, line 94 is on the load function, but after I change the code of load, the error is still in the same line, so Im not sure if thats even correct. Here is the code:
// Implements a dictionary's functionality
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <stdint.h>
#include "dictionary.h"
// Represents a node in a hash table
typedef struct node
{
char word[LENGTH + 1];
struct node *next;
}
node;
int word_count = 0;
// Number of buckets in hash table
const unsigned int N = sizeof(143000 * .75);
// Hash table
node *table[N];
// Returns true if word is in dictionary else false
bool check(const char *word)
{
int key = hash(word);
node *tmp = table[key];
while(tmp->next != NULL)
{
if (strcmp(tmp->word, word) == 0)
{
return true;
}
else
{
tmp = tmp->next;
}
}
// TODO
return false;
}
// Hashes word to a number
unsigned int hash(const char *word)
{
unsigned long hashed = 5381;
int c;
while ((c = *word++))
{
hashed = (((hashed << 5) + hashed) + c);
}
return hashed;
}
// Loads dictionary into memory, returning true if successful else false
bool load(const char *dictionary)
{
node *n = NULL;
char *dict_word = NULL;
FILE *file = fopen(dictionary, "r");
if (file == NULL)
{
return false;
}
while (scanf(dictionary, "%s", dict_word) != EOF)
{
dict_word = malloc(LENGTH);
if (dict_word == NULL)
{
return false;
}
n = malloc(sizeof(node));
if (n == NULL)
{
return false;
}
strcpy(n->word, dict_word);
n->next = NULL;
int key = hash(dict_word);
n->next = table[key];
table[key] = n;
word_count++;
}
fclose(file);
return true;
}
// Returns number of words in dictionary if loaded else 0 if not yet loaded
unsigned int size(void)
{
return word_count;
}
// Unloads dictionary from memory, returning true if successful else false
bool unload(void)
{
for (int i = 0; i < N; i++)
{
node *tmp = table[i];
node *remover = table[i];
while (tmp->next != NULL)
{
tmp = tmp->next;
free(remover);
remover->next = tmp;
}
}
// TODO
return true;
}
The other functions surely arent right, but I cant even test them with this seg fault error. Any help would be really appreciated. Thanks in advance for reading.
