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      1 /***************************************************************************
      2  *                                  _   _ ____  _
      3  *  Project                     ___| | | |  _ \| |
      4  *                             / __| | | | |_) | |
      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel (at) haxx.se>, et al.
      9  *
     10  * This software is licensed as described in the file COPYING, which
     11  * you should have received as part of this distribution. The terms
     12  * are also available at https://curl.haxx.se/docs/copyright.html.
     13  *
     14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
     15  * copies of the Software, and permit persons to whom the Software is
     16  * furnished to do so, under the terms of the COPYING file.
     17  *
     18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
     19  * KIND, either express or implied.
     20  *
     21  ***************************************************************************/
     22 /* <DESC>
     23  * Show how CURLOPT_DEBUGFUNCTION can be used.
     24  * </DESC>
     25  */
     26 #include <stdio.h>
     27 #include <curl/curl.h>
     28 
     29 struct data {
     30   char trace_ascii; /* 1 or 0 */
     31 };
     32 
     33 static
     34 void dump(const char *text,
     35           FILE *stream, unsigned char *ptr, size_t size,
     36           char nohex)
     37 {
     38   size_t i;
     39   size_t c;
     40 
     41   unsigned int width=0x10;
     42 
     43   if(nohex)
     44     /* without the hex output, we can fit more on screen */
     45     width = 0x40;
     46 
     47   fprintf(stream, "%s, %10.10ld bytes (0x%8.8lx)\n",
     48           text, (long)size, (long)size);
     49 
     50   for(i=0; i<size; i+= width) {
     51 
     52     fprintf(stream, "%4.4lx: ", (long)i);
     53 
     54     if(!nohex) {
     55       /* hex not disabled, show it */
     56       for(c = 0; c < width; c++)
     57         if(i+c < size)
     58           fprintf(stream, "%02x ", ptr[i+c]);
     59         else
     60           fputs("   ", stream);
     61     }
     62 
     63     for(c = 0; (c < width) && (i+c < size); c++) {
     64       /* check for 0D0A; if found, skip past and start a new line of output */
     65       if(nohex && (i+c+1 < size) && ptr[i+c]==0x0D && ptr[i+c+1]==0x0A) {
     66         i+=(c+2-width);
     67         break;
     68       }
     69       fprintf(stream, "%c",
     70               (ptr[i+c]>=0x20) && (ptr[i+c]<0x80)?ptr[i+c]:'.');
     71       /* check again for 0D0A, to avoid an extra \n if it's at width */
     72       if(nohex && (i+c+2 < size) && ptr[i+c+1]==0x0D && ptr[i+c+2]==0x0A) {
     73         i+=(c+3-width);
     74         break;
     75       }
     76     }
     77     fputc('\n', stream); /* newline */
     78   }
     79   fflush(stream);
     80 }
     81 
     82 static
     83 int my_trace(CURL *handle, curl_infotype type,
     84              char *data, size_t size,
     85              void *userp)
     86 {
     87   struct data *config = (struct data *)userp;
     88   const char *text;
     89   (void)handle; /* prevent compiler warning */
     90 
     91   switch (type) {
     92   case CURLINFO_TEXT:
     93     fprintf(stderr, "== Info: %s", data);
     94   default: /* in case a new one is introduced to shock us */
     95     return 0;
     96 
     97   case CURLINFO_HEADER_OUT:
     98     text = "=> Send header";
     99     break;
    100   case CURLINFO_DATA_OUT:
    101     text = "=> Send data";
    102     break;
    103   case CURLINFO_SSL_DATA_OUT:
    104     text = "=> Send SSL data";
    105     break;
    106   case CURLINFO_HEADER_IN:
    107     text = "<= Recv header";
    108     break;
    109   case CURLINFO_DATA_IN:
    110     text = "<= Recv data";
    111     break;
    112   case CURLINFO_SSL_DATA_IN:
    113     text = "<= Recv SSL data";
    114     break;
    115   }
    116 
    117   dump(text, stderr, (unsigned char *)data, size, config->trace_ascii);
    118   return 0;
    119 }
    120 
    121 int main(void)
    122 {
    123   CURL *curl;
    124   CURLcode res;
    125   struct data config;
    126 
    127   config.trace_ascii = 1; /* enable ascii tracing */
    128 
    129   curl = curl_easy_init();
    130   if(curl) {
    131     curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, my_trace);
    132     curl_easy_setopt(curl, CURLOPT_DEBUGDATA, &config);
    133 
    134     /* the DEBUGFUNCTION has no effect until we enable VERBOSE */
    135     curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
    136 
    137     /* example.com is redirected, so we tell libcurl to follow redirection */
    138     curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
    139 
    140     curl_easy_setopt(curl, CURLOPT_URL, "http://example.com/");
    141     res = curl_easy_perform(curl);
    142     /* Check for errors */
    143     if(res != CURLE_OK)
    144       fprintf(stderr, "curl_easy_perform() failed: %s\n",
    145               curl_easy_strerror(res));
    146 
    147     /* always cleanup */
    148     curl_easy_cleanup(curl);
    149   }
    150   return 0;
    151 }
    152