Re: [Dev-C++] Free memory problem

Check your allocations again.

Your first loop - where you allocate - is using loop variable a.
However, you assign the memory blocks using variable i (always=0).

All allocations will then be assigned to the first entry in the array,
resulting in a memory leak.

The second loop will then try to free u ninitialized pointers.

By the way - why loop backwards on 'a' and then look up using 'index-a'.

/Per W

On Thu, 2 Nov 2006, Daniel Yan wrote:

> Hi, all,
>
> I met a problem when I free an array of points. The source code is as
> following:
>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
>
> char *http_parampos[255] = { "name=rule1",
>                              "protocol=tcp",
>                              "sourip=172.16.12.53",
>                              "sourport=3256",
>                              "desip=172.16.12.98",
>                              "desport=9685",
>                            };
>
> int main(void)
> {
>    int a = 5;
>    int i = 0;
>    char *value[7];
>    char param_name[40];
>    char *param_value;
>    int index = 5;
>
>    for (;a >= 0;a--)
>    {
>       strncpy(param_name, http_parampos[index - a], sizeof(param_name));
>        param_value = strchr(param_name,'=');
>        if (param_value)
>        {
>           *param_value = '\0';
>           param_value++;
>
>           value[i] = malloc(sizeof(param_value)+1);
>           strcpy(value[i], param_value);
>           printf("value[%d] = %s\n", i, value[i]);
>           //free(value[i]);
>        }
>        i++;
>    }
>
>    value[6] = 0;
>    i = 0;
>
>    printf("come to error!\n");
>
>    for(i = 0; i < 6; i++)
>    {
>          free(value[i]);
>    }
>
>     getch();
>     return 0;
> }
>
> When I tried to free the memory, it breaks down. I have tried these code
> with gcc and it works. And if I free the memory just after I malloc the
> memory(see the coments line), it also works.Could anyone tell me what was
> wrong with my codes?
> Thanks in advance.
>
> BR,
> Daniel
>