CMakeLua/Utilities/cmcurl-7.19.0/docs/examples/getinmemory.c

   1 /*****************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * $Id: getinmemory.c,v 1.1.1.1 2008-09-23 16:32:05 hoffman Exp $
   9  *
  10  * Example source code to show how the callback function can be used to
  11  * download data into a chunk of memory instead of storing it in a file.
  12  *
  13  * This exact source code has not been verified to work.
  14  */
  15
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19
  20 #include <curl/curl.h>
  21 #include <curl/types.h>
  22 #include <curl/easy.h>
  23
  24 struct MemoryStruct {
  25   char *memory;
  26   size_t size;
  27 };
  28
  29 static void *myrealloc(void *ptr, size_t size)
  30 {
  31   /* There might be a realloc() out there that doesn't like reallocing
  32      NULL pointers, so we take care of it here */
  33   if(ptr)
  34     return realloc(ptr, size);
  35   else
  36     return malloc(size);
  37 }
  38
  39 static size_t
  40 WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *data)
  41 {
  42   size_t realsize = size * nmemb;
  43   struct MemoryStruct *mem = (struct MemoryStruct *)data;
  44
  45   mem->memory = (char *)myrealloc(mem->memory, mem->size + realsize + 1);
  46   if (mem->memory) {
  47     memcpy(&(mem->memory[mem->size]), ptr, realsize);
  48     mem->size += realsize;
  49     mem->memory[mem->size] = 0;
  50   }
  51   return realsize;
  52 }
  53
  54 int main(int argc, char **argv)
  55 {
  56   CURL *curl_handle;
  57
  58   struct MemoryStruct chunk;
  59
  60   chunk.memory=NULL; /* we expect realloc(NULL, size) to work */
  61   chunk.size = 0;    /* no data at this point */
  62
  63   curl_global_init(CURL_GLOBAL_ALL);
  64
  65   /* init the curl session */
  66   curl_handle = curl_easy_init();
  67
  68   /* specify URL to get */
  69   curl_easy_setopt(curl_handle, CURLOPT_URL, "http://cool.haxx.se/");
  70
  71   /* send all data to this function  */
  72   curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
  73
  74   /* we pass our 'chunk' struct to the callback function */
  75   curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);
  76
  77   /* some servers don't like requests that are made without a user-agent
  78      field, so we provide one */
  79   curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");
  80
  81   /* get it! */
  82   curl_easy_perform(curl_handle);
  83
  84   /* cleanup curl stuff */
  85   curl_easy_cleanup(curl_handle);
  86
  87   /*
  88    * Now, our chunk.memory points to a memory block that is chunk.size
  89    * bytes big and contains the remote file.
  90    *
  91    * Do something nice with it!
  92    *
  93    * You should be aware of the fact that at this point we might have an
  94    * allocated data block, and nothing has yet deallocated that data. So when
  95    * you're done with it, you should free() it as a nice application.
  96    */
  97
  98   if(chunk.memory)
  99     free(chunk.memory);
 100
 101   /* we're done with libcurl, so clean it up */
 102   curl_global_cleanup();
 103
 104   return 0;
 105 }