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/*****************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
*
* Example source code to show how the callback function can be used to
* download data into a chunk of memory instead of storing it in a file.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
struct MemoryStruct {
char *memory;
size_t size;
};
static size_t
WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *data)
{
size_t realsize = size * nmemb;
struct MemoryStruct *mem = (struct MemoryStruct *)data;
mem->memory = realloc(mem->memory, mem->size + realsize + 1);
if (mem->memory == NULL) {
/* out of memory! */
printf("not enough memory (realloc returned NULL)\n");
exit(EXIT_FAILURE);
}
memcpy(&(mem->memory[mem->size]), ptr, realsize);
mem->size += realsize;
mem->memory[mem->size] = 0;
return realsize;
}
int main(void)
{
CURL *curl_handle;
struct MemoryStruct chunk;
chunk.memory = malloc(1); /* will be grown as needed by the realloc above */
chunk.size = 0; /* no data at this point */
curl_global_init(CURL_GLOBAL_ALL);
/* init the curl session */
curl_handle = curl_easy_init();
/* specify URL to get */
curl_easy_setopt(curl_handle, CURLOPT_URL, "http://www.example.com/");
/* send all data to this function */
curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
/* we pass our 'chunk' struct to the callback function */
curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);
/* some servers don't like requests that are made without a user-agent
field, so we provide one */
curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");
/* get it! */
curl_easy_perform(curl_handle);
/* cleanup curl stuff */
curl_easy_cleanup(curl_handle);
/*
* Now, our chunk.memory points to a memory block that is chunk.size
* bytes big and contains the remote file.
*
* Do something nice with it!
*
* You should be aware of the fact that at this point we might have an
* allocated data block, and nothing has yet deallocated that data. So when
* you're done with it, you should free() it as a nice application.
*/
printf("%lu bytes retrieved\n", (long)chunk.size);
if(chunk.memory)
free(chunk.memory);
/* we're done with libcurl, so clean it up */
curl_global_cleanup();
return 0;
}
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