I want to retrieve the information data of a particular website (url) and
also find its follow-up url (url_new) but getting too many errors after
running Valgrind along with memory leakage.

The function and part of the main program is as follows:

void handle_url_followup(char* url, char** mapping_data, char** url_n)
{
CURL *curl;
char *url_new="NULL";

struct url_data data;
data.size = 0;
data.data = malloc(4096); /* reasonable size initial buffer */
    if(NULL == data.data)
    {
fprintf(stderr, "Failed to allocate memory.\n");
return NULL;
}

    data.data[0] = '\0';

    CURLcode res;

    curl = curl_easy_init();
    if (curl)
    {
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &data);
curl_easy_perform(curl);
curl_easy_getinfo(curl,CURLINFO_EFFECTIVE_URL,&url_new);
res = curl_easy_perform(curl);
if(res != CURLE_OK)
{
fprintf(stderr, "curl_easy_perform() failed: %s\n",
curl_easy_strerror(res));
}
    }
curl_easy_cleanup(curl);
*mapping_data=data.data;
*url_n=url_new;
}

int main(int argc,char *argv[])
{
char url[100]="NULL";
char *mapping_data="NULL";
char *url_new="NULL";

//FIRST URL printf("URL: %s\n", url);
handle_url_followup(url,&mapping_data,&url_new);
//SECOND URL
printf("%s\n",url_new);

I get both the urls but in addition get 973 errors with Valgrind and memory
leakage of 403 bytes in 9 blocks. A few errors are:

==6599== Invalid read of size 1
==6599== at 0x1000124F6: strlen (mc_replace_strmem.c:282)
==6599== by 0x10010AEF4: puts (in /usr/lib/libSystem.B.dylib)
==6599== by 0x1000019F9: main (prog.c:247)
==6599== Address 0x1011db5d0 is 0 bytes inside a block of size 51 free'd
==6599== at 0x100010E9F: free (vg_replace_malloc.c:366)
==6599== by 0x100037C6B: Curl_close (in /usr/lib/libcurl.4.dylib)
==6599== by 0x100001055: handle_url_followup (prog.c:113)
==6599== by 0x1000019ED: main (prog.c:245)

==6599== Invalid read of size 8
==6599== at 0x100013C30: memcpy (mc_replace_strmem.c:635)
==6599== by 0x100096E74: __sfvwrite (in /usr/lib/libSystem.B.dylib)
==6599== by 0x10010AF66: puts (in /usr/lib/libSystem.B.dylib)
==6599== by 0x1000019F9: main (prog.c:247)
==6599== Address 0x1011db5d0 is 0 bytes inside a block of size 51 free'd
==6599== at 0x100010E9F: free (vg_replace_malloc.c:366)
==6599== by 0x100037C6B: Curl_close (in /usr/lib/libcurl.4.dylib)
==6599== by 0x100001055: handle_url_followup (prog.c:113)
==6599== by 0x1000019ED: main (prog.c:245)
==6599==

==6599==
==6599== HEAP SUMMARY:
==6599== in use at exit: 320,629 bytes in 3,035 blocks
==6599== total heap usage: 5,023 allocs, 1,988 frees, 925,560 bytes
allocated
==6599==
==6599== 403 bytes in 9 blocks are definitely lost in loss record 827 of 897
==6599== at 0x10001155D: realloc (vg_replace_malloc.c:525)
==6599== by 0x100000D05: write_data (Gwidd_uniprot_map2.c:23)
==6599== by 0x10002DD9A: Curl_client_write (in /usr/lib/libcurl.4.dylib)
==6599== by 0x1000431F9: Curl_readwrite (in /usr/lib/libcurl.4.dylib)
==6599== by 0x1000439C1: Curl_perform (in /usr/lib/libcurl.4.dylib)
==6599== by 0x10000101D: handle_url_followup (Gwidd_uniprot_map2.c:106)
==6599== by 0x1000019ED: main (Gwidd_uniprot_map2.c:245)
==6599==
==6599== LEAK SUMMARY:
==6599== definitely lost: 403 bytes in 9 blocks

Any suggestion would be highly appreciated.

Thanks!

N.B. The other functions are:

struct url_data
{
size_t size;
char* data;
};

size_t write_data(void *ptr, size_t size, size_t nmemb, struct url_data
*data)
{
size_t index = data->size;
size_t n = (size * nmemb);
char* tmp;

data->size += (size * nmemb);

#ifdef DEBUG
    fprintf(stderr, "data at %p size=%ld nmemb=%ld\n", ptr, size, nmemb);
#endif
tmp = realloc(data->data, data->size + 1); /* +1 for '\0' */

    if(tmp)
    {
data->data = tmp;
    }
    else
    {
if(data->data)
{
free(data->data);
        }
        fprintf(stderr, "Failed to allocate memory.\n");
        return 0;
    }
memcpy((data->data + index), ptr, n);
    data->data[data->size] = '\0';

    return size * nmemb;
}

-------------------------------------------------------------------
List admin: http://cool.haxx.se/list/listinfo/curl-library
Etiquette: http://curl.haxx.se/mail/etiquette.html
Received on 2014-08-05