multi-app.c

/*****************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * $Id: multi-app.c,v 1.9 2008-05-22 21:20:09 danf Exp $
 *
 * This is an example application source code using the multi interface.
 */ 
 
#include <stdio.h>
#include <string.h>
 
/* somewhat unix-specific */ 
#include <sys/time.h>
#include <unistd.h>
 
/* curl stuff */ 
#include <curl/curl.h>
 
/*
 * Download a HTTP file and upload an FTP file simultaneously.
 */ 
 
#define HANDLECOUNT 2    
#define HTTP_HANDLE 0    
#define FTP_HANDLE 1     
 
int main(int argc, char **argv)
{
  CURL *handles[HANDLECOUNT];
  CURLM *multi_handle;
 
  int still_running; /* keep number of running handles */ 
  int i;
 
  CURLMsg *msg; /* for picking up messages with the transfer status */ 
  int msgs_left; /* how many messages are left */ 
 
  /* Allocate one CURL handle per transfer */ 
  for (i=0; i<HANDLECOUNT; i++)
      handles[i] = curl_easy_init();
 
  /* set the options (I left out a few, you'll get the point anyway) */ 
  curl_easy_setopt(handles[HTTP_HANDLE], CURLOPT_URL, "http://website.com");
 
  curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_URL, "ftp://ftpsite.com");
  curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_UPLOAD, 1L);
 
  /* init a multi stack */ 
  multi_handle = curl_multi_init();
 
  /* add the individual transfers */ 
  for (i=0; i<HANDLECOUNT; i++)
      curl_multi_add_handle(multi_handle, handles[i]);
 
  /* we start some action by calling perform right away */ 
  while(CURLM_CALL_MULTI_PERFORM ==
        curl_multi_perform(multi_handle, &still_running));
 
  while(still_running) {
    struct timeval timeout;
    int rc; /* select() return code */ 
 
    fd_set fdread;
    fd_set fdwrite;
    fd_set fdexcep;
    int maxfd;
 
    FD_ZERO(&fdread);
    FD_ZERO(&fdwrite);
    FD_ZERO(&fdexcep);
 
    /* set a suitable timeout to play around with */ 
    timeout.tv_sec = 1;
    timeout.tv_usec = 0;
 
    /* get file descriptors from the transfers */ 
    curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
 
    /* In a real-world program you OF COURSE check the return code of the
       function calls, *and* you make sure that maxfd is bigger than -1 so
       that the call to select() below makes sense! */ 
 
    rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
 
    switch(rc) {
    case -1:
      /* select error */ 
      break;
    case 0:
      /* timeout, do something else */ 
      break;
    default:
      /* one or more of curl's file descriptors say there's data to read
         or write */ 
      while(CURLM_CALL_MULTI_PERFORM ==
            curl_multi_perform(multi_handle, &still_running));
      break;
    }
  }
 
  /* See how the transfers went */ 
  while ((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
    if (msg->msg == CURLMSG_DONE) {
 
       int idx, found = 0;
 
       /* Find out which handle this message is about */ 
       for (idx=0; (!found && (idx<HANDLECOUNT)); idx++) found = (msg->easy_handle == handles[idx]);
 
       switch (idx) {
         case HTTP_HANDLE:
           printf("HTTP transfer completed with status %d\n", msg->data.result);
           break;
         case FTP_HANDLE:
           printf("FTP transfer completed with status %d\n", msg->data.result);
           break;
       }
    }
  }
 
  curl_multi_cleanup(multi_handle);
 
  /* Free the CURL handles */ 
  for (i=0; i<HANDLECOUNT; i++)
      curl_easy_cleanup(handles[i]);
 
  return 0;
}

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