NAME¶

CURLOPT_DEBUGFUNCTION - debug callback

SYNOPSIS¶

#include <curl/curl.h>
typedef enum {


  CURLINFO_TEXT = 0,


  CURLINFO_HEADER_IN,    /* 1 */


  CURLINFO_HEADER_OUT,   /* 2 */


  CURLINFO_DATA_IN,      /* 3 */


  CURLINFO_DATA_OUT,     /* 4 */


  CURLINFO_SSL_DATA_IN,  /* 5 */


  CURLINFO_SSL_DATA_OUT, /* 6 */


  CURLINFO_END
} curl_infotype;
int debug_callback(CURL *handle,


                   curl_infotype type,


                   char *data,


                   size_t size,


                   void *userptr);
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DEBUGFUNCTION,


                          debug_callback);

DESCRIPTION¶

Pass a pointer to your callback function, which should match the prototype shown above.

CURLOPT_DEBUGFUNCTION(3) replaces the standard debug function used when CURLOPT_VERBOSE(3) is in effect. This callback receives debug information, as specified in the type argument. This function must return 0. The data pointed to by the char * passed to this function WILL NOT be null-terminated, but will be exactly of the size as told by the size argument.

The userptr argument is the pointer set with CURLOPT_DEBUGDATA(3).

Available curl_infotype values:

CURLINFO_TEXT

The data is informational text.

CURLINFO_HEADER_IN

The data is header (or header-like) data received from the peer.

CURLINFO_HEADER_OUT

The data is header (or header-like) data sent to the peer.

CURLINFO_DATA_IN

The data is protocol data received from the peer.

CURLINFO_DATA_OUT

The data is protocol data sent to the peer.

CURLINFO_SSL_DATA_OUT

The data is SSL/TLS (binary) data sent to the peer.

CURLINFO_SSL_DATA_IN

The data is SSL/TLS (binary) data received from the peer.

DEFAULT¶

NULL

PROTOCOLS¶

All

EXAMPLE¶

static
void dump(const char *text,


          FILE *stream, unsigned char *ptr, size_t size)
{


  size_t i;


  size_t c;


  unsigned int width=0x10;


  fprintf(stream, "%s, %10.10ld bytes (0x%8.8lx)\n",


          text, (long)size, (long)size);


  for(i=0; i<size; i+= width) {


    fprintf(stream, "%4.4lx: ", (long)i);


    /* show hex to the left */


    for(c = 0; c < width; c++) {


      if(i+c < size)


        fprintf(stream, "%02x ", ptr[i+c]);


      else


        fputs("   ", stream);


    }


    /* show data on the right */


    for(c = 0; (c < width) && (i+c < size); c++) {


      char x = (ptr[i+c] >= 0x20 && ptr[i+c] < 0x80) ? ptr[i+c] : '.';


      fputc(x, stream);


    }


    fputc('\n', stream); /* newline */


  }
}
static
int my_trace(CURL *handle, curl_infotype type,


             char *data, size_t size,


             void *userp)
{


  const char *text;


  (void)handle; /* prevent compiler warning */


  (void)userp;


  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_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;


  }


  dump(text, stderr, (unsigned char *)data, size);


  return 0;
}
int main(void)
{


  CURL *curl;


  CURLcode res;


  curl = curl_easy_init();


  if(curl) {


    curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, my_trace);


    /* 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);


  }


  return 0;
}

AVAILABILITY¶

Always

RETURN VALUE¶

Returns CURLE_OK

SEE ALSO¶

CURLOPT_VERBOSE(3), CURLOPT_DEBUGDATA(3),