curl / libcurl / API / Examples / multi-formadd.c

multi-formadd.c

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 * Copyright (C) 1998 - 2021, 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
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 * furnished to do so, under the terms of the COPYING file.
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 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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/* <DESC>
 * using the multi interface to do a multipart formpost without blocking
 * </DESC>
 */
 
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
 
#include <curl/curl.h>
 
int main(void)
{
  CURL *curl;
 
  CURLM *multi_handle;
  int still_running = 0;
 
  struct curl_httppost *formpost = NULL;
  struct curl_httppost *lastptr = NULL;
  struct curl_slist *headerlist = NULL;
  static const char buf[] = "Expect:";
 
  /* Fill in the file upload field. This makes libcurl load data from
     the given file name when curl_easy_perform() is called. */
  curl_formadd(&formpost,
               &lastptr,
               CURLFORM_COPYNAME, "sendfile",
               CURLFORM_FILE, "postit2.c",
               CURLFORM_END);
 
  /* Fill in the filename field */
  curl_formadd(&formpost,
               &lastptr,
               CURLFORM_COPYNAME, "filename",
               CURLFORM_COPYCONTENTS, "postit2.c",
               CURLFORM_END);
 
  /* Fill in the submit field too, even if this is rarely needed */
  curl_formadd(&formpost,
               &lastptr,
               CURLFORM_COPYNAME, "submit",
               CURLFORM_COPYCONTENTS, "send",
               CURLFORM_END);
 
  curl = curl_easy_init();
  multi_handle = curl_multi_init();
 
  /* initialize custom header list (stating that Expect: 100-continue is not
     wanted */
  headerlist = curl_slist_append(headerlist, buf);
  if(curl && multi_handle) {
 
    /* what URL that receives this POST */
    curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/upload.cgi");
    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
 
    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist);
    curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
 
    curl_multi_add_handle(multi_handle, curl);
 
    do {
      CURLMcode mc = curl_multi_perform(multi_handle, &still_running);
 
      if(still_running)
        /* wait for activity, timeout or "nothing" */
        mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL);
 
      if(mc)
        break;
 
    } while(still_running);
 
    curl_multi_cleanup(multi_handle);
 
    /* always cleanup */
    curl_easy_cleanup(curl);
 
    /* then cleanup the formpost chain */
    curl_formfree(formpost);
 
    /* free slist */
    curl_slist_free_all(headerlist);
  }
  return 0;
}