/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2011, 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 http://curl.haxx.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.
 *
 ***************************************************************************/ 
/* 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.
 * After successful download we use curl_easy_getinfo() calls to get the
 * amount of downloaded bytes, the time used for the whole download, and
 * the average download speed.
 * On Linux you can create the download test files with:
 * dd if=/dev/urandom of=file_1M.bin bs=1M count=1
 *
 */ 
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
 
#include <curl/curl.h>
 
#define URL_BASE "http://speedtest.your.domain/"
#define URL_1M   URL_BASE "file_1M.bin"
#define URL_2M   URL_BASE "file_2M.bin"
#define URL_5M   URL_BASE "file_5M.bin"
#define URL_10M  URL_BASE "file_10M.bin"
#define URL_20M  URL_BASE "file_20M.bin"
#define URL_50M  URL_BASE "file_50M.bin"
#define URL_100M URL_BASE "file_100M.bin"
 
#define CHKSPEED_VERSION "1.0"
 
static size_t WriteCallback(void *ptr, size_t size, size_t nmemb, void *data)
{
  /* we are not interested in the downloaded bytes itself,
     so we only return the size we would have saved ... */ 
  (void)ptr;  /* unused */ 
  (void)data; /* unused */ 
  return (size_t)(size * nmemb);
}
 
int main(int argc, char *argv[])
{
  CURL *curl_handle;
  CURLcode res;
  int prtsep = 0, prttime = 0;
  const char *url = URL_1M;
  char *appname = argv[0];
 
  if (argc > 1) {
    /* parse input parameters */ 
    for (argc--, argv++; *argv; argc--, argv++) {
      if (strncasecmp(*argv, "-", 1) == 0) {
        if (strncasecmp(*argv, "-H", 2) == 0) {
          fprintf(stderr,
                  "\rUsage: %s [-m=1|2|5|10|20|50|100] [-t] [-x] [url]\n",
                  appname);
          exit(1);
        } else if (strncasecmp(*argv, "-V", 2) == 0) {
          fprintf(stderr, "\r%s %s - %s\n",
                  appname, CHKSPEED_VERSION, curl_version());
          exit(1);
        } else if (strncasecmp(*argv, "-X", 2) == 0) {
          prtsep = 1;
        } else if (strncasecmp(*argv, "-T", 2) == 0) {
          prttime = 1;
        } else if (strncasecmp(*argv, "-M=", 3) == 0) {
          long m = strtol((*argv)+3, NULL, 10);
          switch(m) {
            case   1: url = URL_1M;
                      break;
            case   2: url = URL_2M;
                      break;
            case   5: url = URL_5M;
                      break;
            case  10: url = URL_10M;
                      break;
            case  20: url = URL_20M;
                      break;
            case  50: url = URL_50M;
                      break;
            case 100: url = URL_100M;
                      break;
            default:  fprintf(stderr, "\r%s: invalid parameter %s\n",
                              appname, *argv + 3);
                      exit(1);
          }
        } else {
          fprintf(stderr, "\r%s: invalid or unknown option %s\n",
                  appname, *argv);
          exit(1);
        }
      } else {
        url = *argv;
      }
    }
  }
 
  /* print separator line */ 
  if (prtsep) {
    printf("-------------------------------------------------\n");
  }
  /* print localtime */ 
  if (prttime) {
    time_t t = time(NULL);
    printf("Localtime: %s", ctime(&t));
  }
 
  /* init libcurl */ 
  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, url);
 
  /* send all data to this function  */ 
  curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteCallback);
 
  /* 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-speedchecker/" CHKSPEED_VERSION);
 
  /* get it! */ 
  res = curl_easy_perform(curl_handle);
 
  if(CURLE_OK == res) {
    double val;
 
    /* check for bytes downloaded */ 
    res = curl_easy_getinfo(curl_handle, CURLINFO_SIZE_DOWNLOAD, &val);
    if((CURLE_OK == res) && (val>0))
      printf("Data downloaded: %0.0f bytes.\n", val);
 
    /* check for total download time */ 
    res = curl_easy_getinfo(curl_handle, CURLINFO_TOTAL_TIME, &val);
    if((CURLE_OK == res) && (val>0))
      printf("Total download time: %0.3f sec.\n", val);
 
    /* check for average download speed */ 
    res = curl_easy_getinfo(curl_handle, CURLINFO_SPEED_DOWNLOAD, &val);
    if((CURLE_OK == res) && (val>0))
      printf("Average download speed: %0.3f kbyte/sec.\n", val / 1024);
 
  } else {
    fprintf(stderr, "Error while fetching '%s' : %s\n",
            url, curl_easy_strerror(res));
  }
 
  /* cleanup curl stuff */ 
  curl_easy_cleanup(curl_handle);
 
  /* we're done with libcurl, so clean it up */ 
  curl_global_cleanup();
 
  return 0;
}

You'll also find all examples in the distribution archive, in the docs/examples directory.

Page updated January 16, 2012.
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