debug.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * 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>
 * Show how CURLOPT_DEBUGFUNCTION can be used.
 * </DESC>
 */
#include <stdio.h>
 
#include <curl/curl.h>
 
struct data {
  char trace_ascii; /* 1 or 0 */
};
 
static void dump(const char *text, const unsigned char *ptr,
                 size_t size, char 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(stderr, "%s, %lu bytes (0x%lx)\n",
          text, (unsigned long)size, (unsigned long)size);
 
  for(i = 0; i < size; i += width) {
 
    fprintf(stderr, "%4.4lx: ", (unsigned long)i);
 
    if(!nohex) {
      /* hex not disabled, show it */
      for(c = 0; c < width; c++)
        if(i + c < size)
          fprintf(stderr, "%02x ", ptr[i + c]);
        else
          fputs("   ", stderr);
    }
 
    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(stderr, "%c",
              (ptr[i + c] >= 0x20) && (ptr[i + c] < 0x80) ? ptr[i + c] : '.');
      /* check again for 0D0A, to avoid an extra \n if it is 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', stderr); /* newline */
  }
}
 
static int my_trace(CURL *curl, curl_infotype type,
                    char *data, size_t size, void *userp)
{
  struct data *config = (struct data *)userp;
  const char *text;
  (void)curl;
 
  switch(type) {
  case CURLINFO_TEXT:
    fprintf(stderr, "== Info: %s", data);
    return 0;
  case CURLINFO_HEADER_OUT:
    text = "=> Send header";
    break;
  case CURLINFO_DATA_OUT:
    text = "=> Send data";
    break;
  case CURLINFO_SSL_DATA_OUT:
    text = "=> Send SSL data";
    break;
  case CURLINFO_HEADER_IN:
    text = "<= Recv header";
    break;
  case CURLINFO_DATA_IN:
    text = "<= Recv data";
    break;
  case CURLINFO_SSL_DATA_IN:
    text = "<= Recv SSL data";
    break;
  default: /* in case a new one is introduced to shock us */
    return 0;
  }
 
  dump(text, (const unsigned char *)data, size, config->trace_ascii);
  return 0;
}
 
int main(void)
{
  CURL *curl;
  CURLcode result;
  struct data config;
 
  result = curl_global_init(CURL_GLOBAL_ALL);
  if(result != CURLE_OK)
    return (int)result;
 
  config.trace_ascii = 1; /* enable ASCII tracing */
 
  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, my_trace);
    curl_easy_setopt(curl, CURLOPT_DEBUGDATA, &config);
 
    /* the DEBUGFUNCTION has no effect until we enable VERBOSE */
    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
 
    /* example.com is redirected, so we tell libcurl to follow redirection */
    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
 
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    result = curl_easy_perform(curl);
    /* Check for errors */
    if(result != CURLE_OK)
      fprintf(stderr, "curl_easy_perform() failed: %s\n",
              curl_easy_strerror(result));
 
    /* always cleanup */
    curl_easy_cleanup(curl);
  }
  curl_global_cleanup();
  return (int)result;
}

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