Just for the record, I've been using this example code, modified to suit my own purposes, for a couple of months on many different operating systems, as part of my Wikipedia bot. It works perfectly on Windows, OS X, FreeBSD, Linux...

 Richard

----- Original Message -----
From: Martin Möller
Sent: 05/11/11 03:42 AM
To: curl-library_at_cool.haxx.se
Subject: [EXAMPLE] Bug in getinmemory.c

Hello @ all,

 I found a bug in getinmemory.c in docs/examples.
 This version misuses realloc: It resizes a chunk of memory, but doesn’t take into
 account that the realloced memory address changes.

 I think this file was never actually tested.

 Attached is a patch for solving the problem
 (The diff is stored in unified form):

 --- getinmemory.c.orig 2011-05-10 19:23:37.000000000 +0200
 +++ getinmemory.c 2011-05-10 19:30:10.000000000 +0200
 @@ -39,19 +39,24 @@
 WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *data)
 {
 size_t realsize = size * nmemb;
 + char * reall;
 struct MemoryStruct *mem = (struct MemoryStruct *)data;

 - mem->memory = realloc(mem->memory, mem->size + realsize + 1);
 - if (mem->memory == NULL) {
 + reall = malloc(mem->size + realsize + 1);
 + if (reall == NULL) {
 /* out of memory! */
 - printf("not enough memory (realloc returned NULL)\n");
 + printf("not enough memory (malloc returned NULL)\n");
 exit(EXIT_FAILURE);
 }

 - memcpy(&(mem->memory[mem->size]), ptr, realsize);
 + if (mem->memory)
 + memcpy (reall, mem->memory, mem->size);
 +
 + memcpy(reall + mem->size, ptr, realsize);
 mem->size += realsize;
 - mem->memory[mem->size] = 0;
 + reall [mem->size] = 0;

 + mem->memory = reall;
 return realsize;
 }

 @@ -62,7 +67,7 @@

 struct MemoryStruct chunk;

 - chunk.memory = malloc(1); /* will be grown as needed by the realloc above */
 + chunk.memory = NULL; /* will be grown as needed by the malloc above */
 chunk.size = 0; /* no data at this point */

 curl_global_init(CURL_GLOBAL_ALL);
 @@ -71,7 +76,7 @@
 curl_handle = curl_easy_init();

 /* specify URL to get */
 - curl_easy_setopt(curl_handle, CURLOPT_URL, "http://www.example.com/ ");
 + curl_easy_setopt(curl_handle, CURLOPT_URL, "http://www.google.de/ ");

 /* send all data to this function */
 curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);

 ------
 Best regards,
 Martin Moeller

-------------------------------------------------------------------
List admin: http://cool.haxx.se/list/listinfo/curl-library
Etiquette: http://curl.haxx.se/mail/etiquette.html
Received on 2011-05-10