multi-debugcallback.c

/*****************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * $Id: multi-debugcallback.c,v 1.5 2009-06-05 18:40:40 yangtse Exp $
 *
 * This is a very simple example using the multi interface and the debug
 * callback.
 */ 
 
#include <stdio.h>
#include <string.h>
 
/* somewhat unix-specific */ 
#include <sys/time.h>
#include <unistd.h>
 
/* curl stuff */ 
#include <curl/curl.h>
 
typedef char bool;
#define TRUE 1
 
static
void dump(const char *text,
          FILE *stream, unsigned char *ptr, size_t size,
          bool nohex)
{
  size_t i;
  size_t c;
 
  unsigned int width=0x10;
 
  if(nohex)
    /* without the hex output, we can fit more on screen */ 
    width = 0x40;
 
  fprintf(stream, "%s, %010.10ld bytes (0x%08.8lx)\n",
          text, (long)size, (long)size);
 
  for(i=0; i<size; i+= width) {
 
    fprintf(stream, "%04.4lx: ", (long)i);
 
    if(!nohex) {
      /* hex not disabled, show it */ 
      for(c = 0; c < width; c++)
        if(i+c < size)
          fprintf(stream, "%02x ", ptr[i+c]);
        else
          fputs("   ", stream);
    }
 
    for(c = 0; (c < width) && (i+c < size); c++) {
      /* check for 0D0A; if found, skip past and start a new line of output */ 
      if (nohex && (i+c+1 < size) && ptr[i+c]==0x0D && ptr[i+c+1]==0x0A) {
        i+=(c+2-width);
        break;
      }
      fprintf(stream, "%c",
              (ptr[i+c]>=0x20) && (ptr[i+c]<0x80)?ptr[i+c]:'.');
      /* check again for 0D0A, to avoid an extra \n if it's at width */ 
      if (nohex && (i+c+2 < size) && ptr[i+c+1]==0x0D && ptr[i+c+2]==0x0A) {
        i+=(c+3-width);
        break;
      }
    }
    fputc('\n', stream); /* newline */ 
  }
  fflush(stream);
}
 
static
int my_trace(CURL *handle, curl_infotype type,
             unsigned char *data, size_t size,
             void *userp)
{
  const char *text;
 
  (void)handle; /* prevent compiler warning */ 
 
  switch (type) {
  case CURLINFO_TEXT:
    fprintf(stderr, "== Info: %s", data);
  default: /* in case a new one is introduced to shock us */ 
    return 0;
 
  case CURLINFO_HEADER_OUT:
    text = "=> Send header";
    break;
  case CURLINFO_DATA_OUT:
    text = "=> Send data";
    break;
  case CURLINFO_HEADER_IN:
    text = "<= Recv header";
    break;
  case CURLINFO_DATA_IN:
    text = "<= Recv data";
    break;
  }
 
  dump(text, stderr, data, size, TRUE);
  return 0;
}
 
/*
 * Simply download a HTTP file.
 */ 
int main(int argc, char **argv)
{
  CURL *http_handle;
  CURLM *multi_handle;
 
  int still_running; /* keep number of running handles */ 
 
  http_handle = curl_easy_init();
 
  /* set the options (I left out a few, you'll get the point anyway) */ 
  curl_easy_setopt(http_handle, CURLOPT_URL, "http://www.haxx.se/");
 
  curl_easy_setopt(http_handle, CURLOPT_DEBUGFUNCTION, my_trace);
  curl_easy_setopt(http_handle, CURLOPT_VERBOSE, 1L);
 
  /* init a multi stack */ 
  multi_handle = curl_multi_init();
 
  /* add the individual transfers */ 
  curl_multi_add_handle(multi_handle, http_handle);
 
  /* 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 */ 
      still_running = 0;
      printf("select() returns error, this is badness\n");
      break;
    case 0:
    default:
      /* timeout or readable/writable sockets */ 
      while(CURLM_CALL_MULTI_PERFORM ==
            curl_multi_perform(multi_handle, &still_running));
      break;
    }
  }
 
  curl_multi_cleanup(multi_handle);
 
  curl_easy_cleanup(http_handle);
 
  return 0;
}

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