Check50 gives me the munmap_chunk: invalid pointer - it seems I am not copying something right with strcpy. Valgrind gives me: LEAK SUMMARY: still reachable: 608 bytes in 2 blocks
==2864== 56 bytes in 1 blocks are still reachable in loss record 1 of 2
==2864== at 0x4C2FB0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2864== by 0x401208: load (dictionary.c:82)
==2864== by 0x400924: main (speller.c:40)
==2864==
==2864== 552 bytes in 1 blocks are still reachable in loss record 2 of 2
==2864== at 0x4C2FB0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2864== by 0x5258E49: __fopen_internal (iofopen.c:65)
==2864== by 0x5258E49: fopen@@GLIBC_2.2.5 (iofopen.c:89)
==2864== by 0x4011B1: load (dictionary.c:70)
==2864== by 0x400924: main (speller.c:40)
There is one segmentation fault also. The code I wrote (as a beginner in pointers):
// Implements a dictionary's functionality
#include <ctype.h>
#include <stdbool.h>
#include <strings.h>
#include "dictionary.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// Represents a node in a hash table
typedef struct node
{
char word[LENGTH + 1];
struct node *next;
}
node;
// Number of buckets in hash table
const unsigned int N = 676; // number will be 26^2
// Hash table
node *table[N];
// Returns true if word is in dictionary else false
bool check(const char *word)
{
int x = hash(word); // going to the index in the table
// 2 traverse list
node* cursor = NULL;
cursor->next = table[x];
while (cursor != NULL) // cursor is null at the end of the list
{
if (strcasecmp(word, cursor->word) == 0) // daca exista in lista
{
return true;
}
cursor = cursor->next;
}
return false;
}
int hvalue;
// Hashes word to a number
unsigned int hash(const char *word)
{
if (isupper(word[0]) > 0) // daca incepe cu litera mare
{ // mare // mica
hvalue = (word[0] - 65) * 26 + (word[1] - 96);
return hvalue;
}
else if (isupper(word[1]) > 0) // highly improbable :OK, KO
{ // mare // mare
hvalue = (word[0] - 65) * 26 + (word[1] - 65);
return hvalue;
}
else if (word[1] == '\000') // hash 1 letter words
{
hvalue = word[0] - 96;
return hvalue;
}
else
{
hvalue = (word[0] - 96) * 26 + (word[1] - 96);
return hvalue;
}
}
int countWords; // for size function
// Loads dictionary into memory, returning true if successful else false
bool load(const char *dictionary)
{
FILE *file = fopen(dictionary, "r"); // here is line 70 with 1 error
if (file == NULL)
{
fclose(file);
return false;
}
int index;
char word[46];
while (fscanf(file, "%s", word) != EOF) // read in a string
{
// create a new node to put the dictionary word
node *newOne = malloc(sizeof(node)); // here is line 82 with 2nd error
if (newOne == NULL)
{
fclose(file);
free(newOne);
return false;
}
// strcpy(word field of node, src word)
strcpy(newOne->word, word);
index = hash(word);
countWords++;
newOne->next = table[index];
table[index] = newOne;
}
fclose(file);
free(word);
return true;
}
// Returns number of words in dictionary if loaded else 0 if not yet loaded
unsigned int size(void)
{
return countWords;
}
node* cursor = NULL;
node* tmp = NULL;
// Unloads dictionary from memory, returning true if successful else false
bool unload(void)
{
for (int i = 0; i < N; i++) // going through the hashtable
{
cursor->next = table[i];
tmp = cursor;
while (cursor != NULL)
{
cursor = cursor->next;
free(tmp);
tmp = cursor;
}
free(table[i]);
}
return true;
}
Where is the mistake ? I searched around 60 pages of this issue and I couldn't figure it out yet! Thank you!
