quickjs-tart

quickjs-based runtime for wallet-core logic
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getinmemory.c (3333B)

      1 /***************************************************************************
      2  *                                  _   _ ____  _
      3  *  Project                     ___| | | |  _ \| |
      4  *                             / __| | | | |_) | |
      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
      9  *
     10  * This software is licensed as described in the file COPYING, which
     11  * you should have received as part of this distribution. The terms
     12  * are also available at https://curl.se/docs/copyright.html.
     13  *
     14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
     15  * copies of the Software, and permit persons to whom the Software is
     16  * furnished to do so, under the terms of the COPYING file.
     17  *
     18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
     19  * KIND, either express or implied.
     20  *
     21  * SPDX-License-Identifier: curl
     22  *
     23  ***************************************************************************/
     24 /* <DESC>
     25  * Shows how the write callback function can be used to download data into a
     26  * chunk of memory instead of storing it in a file.
     27  * </DESC>
     28  */
     29 
     30 #include <stdio.h>
     31 #include <stdlib.h>
     32 #include <string.h>
     33 
     34 #include <curl/curl.h>
     35 
     36 struct MemoryStruct {
     37   char *memory;
     38   size_t size;
     39 };
     40 
     41 static size_t
     42 WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
     43 {
     44   size_t realsize = size * nmemb;
     45   struct MemoryStruct *mem = (struct MemoryStruct *)userp;
     46 
     47   char *ptr = realloc(mem->memory, mem->size + realsize + 1);
     48   if(!ptr) {
     49     /* out of memory! */
     50     printf("not enough memory (realloc returned NULL)\n");
     51     return 0;
     52   }
     53 
     54   mem->memory = ptr;
     55   memcpy(&(mem->memory[mem->size]), contents, realsize);
     56   mem->size += realsize;
     57   mem->memory[mem->size] = 0;
     58 
     59   return realsize;
     60 }
     61 
     62 int main(void)
     63 {
     64   CURL *curl_handle;
     65   CURLcode res;
     66 
     67   struct MemoryStruct chunk;
     68 
     69   chunk.memory = malloc(1);  /* grown as needed by the realloc above */
     70   chunk.size = 0;    /* no data at this point */
     71 
     72   curl_global_init(CURL_GLOBAL_ALL);
     73 
     74   /* init the curl session */
     75   curl_handle = curl_easy_init();
     76 
     77   /* specify URL to get */
     78   curl_easy_setopt(curl_handle, CURLOPT_URL, "https://www.example.com/");
     79 
     80   /* send all data to this function  */
     81   curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
     82 
     83   /* we pass our 'chunk' struct to the callback function */
     84   curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);
     85 
     86   /* some servers do not like requests that are made without a user-agent
     87      field, so we provide one */
     88   curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");
     89 
     90   /* get it! */
     91   res = curl_easy_perform(curl_handle);
     92 
     93   /* check for errors */
     94   if(res != CURLE_OK) {
     95     fprintf(stderr, "curl_easy_perform() failed: %s\n",
     96             curl_easy_strerror(res));
     97   }
     98   else {
     99     /*
    100      * Now, our chunk.memory points to a memory block that is chunk.size
    101      * bytes big and contains the remote file.
    102      *
    103      * Do something nice with it!
    104      */
    105 
    106     printf("%lu bytes retrieved\n", (unsigned long)chunk.size);
    107   }
    108 
    109   /* cleanup curl stuff */
    110   curl_easy_cleanup(curl_handle);
    111 
    112   free(chunk.memory);
    113 
    114   /* we are done with libcurl, so clean it up */
    115   curl_global_cleanup();
    116 
    117   return 0;
    118 }