curl / libcurl / API / Examples / pop3-multi.c

pop3-multi.c

/***************************************************************************
 *                                  _   _ ____  _
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 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
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 *
 * 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>
 * Get POP3 email using the multi interface
 * </DESC>
 */
 
#include <stdio.h>
#include <string.h>
#include <curl/curl.h>
 
/* This is a simple example showing how to retrieve mail using libcurl's POP3
 * capabilities. It builds on the pop3-retr.c example to demonstrate how to use
 * libcurl's multi interface.
 */
 
int main(void)
{
  CURL *curl;
  CURLM *mcurl;
  int still_running = 1;
 
  curl_global_init(CURL_GLOBAL_DEFAULT);
 
  curl = curl_easy_init();
  if(!curl)
    return 1;
 
  mcurl = curl_multi_init();
  if(!mcurl)
    return 2;
 
  /* Set username and password */
  curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
  curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
 
  /* This retrieves message 1 from the user's mailbox */
  curl_easy_setopt(curl, CURLOPT_URL, "pop3://pop.example.com/1");
 
  /* Tell the multi stack about our easy handle */
  curl_multi_add_handle(mcurl, curl);
 
  do {
    CURLMcode mc = curl_multi_perform(mcurl, &still_running);
 
    if(still_running)
      /* wait for activity, timeout or "nothing" */
      mc = curl_multi_poll(mcurl, NULL, 0, 1000, NULL);
 
    if(mc)
      break;
 
  } while(still_running);
 
  /* Always cleanup */
  curl_multi_remove_handle(mcurl, curl);
  curl_multi_cleanup(mcurl);
  curl_easy_cleanup(curl);
  curl_global_cleanup();
 
  return 0;
}

Notice

This source code example is simplified and ignores return codes and error checks to a large extent. We do this to highlight the libcurl function calls and related options and reduce unrelated code.

A real-world application will of course properly check every return value and exit correctly at the first serious error.