i have a problem with the initialization of the values inside the first dynamic array of pointers
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char*** GetIndexes()
{
int n = 0;
char ***index;
printf("please insert the number of words you want to add to dictionary\n");
scanf("%d", &n);
index = (char***)calloc(n, sizeof(char));
if (index == NULL)
{
printf("allocation Failed");
return;
}
return index;
}
char** GetDefinitions()
{
int n = 0;
char **definition;
printf("please insert the number of defintions you want to add to the word\n");
scanf("%d", &n);
definition = (char**)calloc(n+1, sizeof(char));
if (definition == NULL)
{
printf("allocation failed");
return;
}
return definition;
}
int main()
{
char *** dptr = GetIndexes();
if (dptr == NULL)
{
printf("memory Allocation failed");
}
int indexcount = sizeof(dptr) / sizeof(char),i;
for (i = 0; i < indexcount; i++)
{
printf("word number %d\n", i + 1);
*dptr[i] = GetDefinitions();
}
printf("%p",dptr);
}
i tried running the debugger in VS2013 and after i enter the number of defintions i want it crashed with this message:
Unhandled exception at 0x01103FB0 in ConsoleApplication1.exe: 0xC0000005: Access violation writing location 0x00000000.
i missed an allocation of something but i cant quite figure out what i missed,
thanks in advance
Your program is very broken
You allocate n
char ***
s but only request space for n
char
s and also do it for char **
, to prevent this kind of mistake you may use the sizeof
operator this way
char ***index;
index = calloc(n, sizeof(*index));
and
char **definition;
definition = calloc(n, sizeof(*definition));
and as you see casting calloc
makes it harder and it's not necessary.
You have a return
statement that doesn't return anything an GetIndexes()
as well as one in GetDefinitions
.
They should return NULL
if you want to handle failure in the caller function
return NULL;
You erroneously use the sizeof
operator to determine the number of char ***
pointer allocated in
int indexcount = sizeof(dptr) / sizeof(char)
this will be either 4
or 8
depending on the architecture i.e. the size of a pointer divided by 1 sizeof(char) == 1
always.
You can't compute that value, you simply have to keep track of it. The size
You dereference the triple pointer twice and try to assign a double pointer to it
*dptr[i] = GetDefinitions();
here the operator precedence is also an issue, but regardless of that, this is wrong, may be what you meant was
dptr[i] = GetDefinitions();
This is not going to make your program crash, but it's certainly important to free
all malloc
ed pointers before exiting the program.
Here is a suggestion for your code to work, ignore it's purpose since it's not clear what you are trying to do
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char ***GetIndexes(unsigned int *count)
{
char ***index;
printf("please insert the number of words you want to add to dictionary > ");
scanf("%u", count);
index = calloc(*count, sizeof(*index));
if (index == NULL)
{
printf("allocation Failed");
return NULL;
}
return index;
}
char **GetDefinitions(unsigned int *count)
{
char **definition;
printf("please insert the number of defintions you want to add to the word > ");
scanf("%u", count);
definition = calloc(*count + 1, sizeof(*definition));
if (definition == NULL)
{
printf("allocation failed");
return NULL;
}
return definition;
}
int main()
{
unsigned int indexCount, i;
char ***dptr = GetIndexes(&indexCount);
if (dptr == NULL)
{
printf("memory Allocation failed");
}
for (i = 0; i < indexCount; i++)
{
unsigned int definitionsCount;
printf("Word number %u\n", i + 1);
dptr[i] = GetDefinitions(&definitionsCount);
if (dptr[i] != NULL)
{
/* use dptr[i] here or maybe somewhere else, but when you finish */
free(dptr[i]);
}
}
printf("%p", dptr);
/* now if you are done using dptr */
free(dptr);
return 0;
}