.\" generated by cd2nroff 0.1 from CURLOPT_DEBUGDATA.md
.TH CURLOPT_DEBUGDATA 3 "2024-11-07" libcurl
.SH NAME
CURLOPT_DEBUGDATA \- pointer passed to the debug callback
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DEBUGDATA, void *pointer);
.fi
.SH DESCRIPTION
Pass a \fIpointer\fP to whatever you want passed in to your
\fICURLOPT_DEBUGFUNCTION(3)\fP in the last void * argument. This pointer is
not used by libcurl, it is only passed to the callback.
.SH DEFAULT
NULL
.SH PROTOCOLS
This functionality affects all supported protocols
.SH EXAMPLE
.nf
struct data {
  void *custom;
};

static int my_trace(CURL *handle, curl_infotype type,
                    char *data, size_t size,
                    void *clientp)
{
  struct data *mine = clientp;
  printf("our ptr: %p\\n", mine->custom);

  /* output debug info */
}

int main(void)
{
  CURL *curl;
  CURLcode res;
  struct data my_tracedata;

  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, my_trace);

    curl_easy_setopt(curl, CURLOPT_DEBUGDATA, &my_tracedata);

    /* the DEBUGFUNCTION has no effect until we enable VERBOSE */
    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);

    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    res = curl_easy_perform(curl);

    /* always cleanup */
    curl_easy_cleanup(curl);
  }
  return 0;
}
.fi
.SH AVAILABILITY
Added in curl 7.9.6
.SH RETURN VALUE
Returns CURLE_OK
.SH SEE ALSO
.BR CURLOPT_DEBUGFUNCTION (3),
.BR CURLOPT_STDERR (3)