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, FILE *stream, 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(stream, "%s, %10.10lu bytes (0x%8.8lx)\n",
 text, (unsigned long)size, (unsigned long)size);
 
 for(i = 0; i < size; i += width) {
 
 fprintf(stream, "%4.4lx: ", (unsigned 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,
 char *data, size_t size, void *userp)
{
 struct data *config = (struct data *)userp;
 const char *text;
 (void)handle;
 
 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, stderr, (unsigned char *)data, size, config->trace_ascii);
 return 0;
}
 
int main(void)
{
 CURL *curl;
 CURLcode res;
 struct data config;
 
 res = curl_global_init(CURL_GLOBAL_ALL);
 if(res)
 return (int)res;
 
 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/");
 res = curl_easy_perform(curl);
 /* Check for errors */
 if(res != CURLE_OK)
 fprintf(stderr, "curl_easy_perform() failed: %s\n",
 curl_easy_strerror(res));
 
 /* always cleanup */
 curl_easy_cleanup(curl);
 }
 curl_global_cleanup();
 return (int)res;
}

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