119 lines
3.3 KiB
C
119 lines
3.3 KiB
C
/***************************************************************************
|
|
* _ _ ____ _
|
|
* Project ___| | | | _ \| |
|
|
* / __| | | | |_) | |
|
|
* | (__| |_| | _ <| |___
|
|
* \___|\___/|_| \_\_____|
|
|
*
|
|
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
|
|
*
|
|
* This software is licensed as described in the file COPYING, which
|
|
* you should have received as part of this distribution. The terms
|
|
* are also available at https://curl.se/docs/copyright.html.
|
|
*
|
|
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
|
* copies of the Software, and permit persons to whom the Software is
|
|
* furnished to do so, under the terms of the COPYING file.
|
|
*
|
|
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
* KIND, either express or implied.
|
|
*
|
|
* SPDX-License-Identifier: curl
|
|
*
|
|
***************************************************************************/
|
|
/* <DESC>
|
|
* Shows how the write callback function can be used to download data into a
|
|
* chunk of memory instead of storing it in a file.
|
|
* </DESC>
|
|
*/
|
|
|
|
#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 *contents, size_t size, size_t nmemb, void *userp)
|
|
{
|
|
size_t realsize = size * nmemb;
|
|
struct MemoryStruct *mem = (struct MemoryStruct *)userp;
|
|
|
|
char *ptr = realloc(mem->memory, mem->size + realsize + 1);
|
|
if(!ptr) {
|
|
/* out of memory! */
|
|
printf("not enough memory (realloc returned NULL)\n");
|
|
return 0;
|
|
}
|
|
|
|
mem->memory = ptr;
|
|
memcpy(&(mem->memory[mem->size]), contents, realsize);
|
|
mem->size += realsize;
|
|
mem->memory[mem->size] = 0;
|
|
|
|
return realsize;
|
|
}
|
|
|
|
int main(void)
|
|
{
|
|
CURL *curl_handle;
|
|
CURLcode res;
|
|
|
|
struct MemoryStruct chunk;
|
|
|
|
chunk.memory = malloc(1); /* 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, "https://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 do not 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! */
|
|
res = curl_easy_perform(curl_handle);
|
|
|
|
/* check for errors */
|
|
if(res != CURLE_OK) {
|
|
fprintf(stderr, "curl_easy_perform() failed: %s\n",
|
|
curl_easy_strerror(res));
|
|
}
|
|
else {
|
|
/*
|
|
* 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!
|
|
*/
|
|
|
|
printf("%lu bytes retrieved\n", (unsigned long)chunk.size);
|
|
}
|
|
|
|
/* cleanup curl stuff */
|
|
curl_easy_cleanup(curl_handle);
|
|
|
|
free(chunk.memory);
|
|
|
|
/* we are done with libcurl, so clean it up */
|
|
curl_global_cleanup();
|
|
|
|
return 0;
|
|
}
|