.\" generated by cd2nroff 0.1 from CURLOPT_DEBUGDATA.md .TH CURLOPT_DEBUGDATA 3 "March 22 2024" libcurl .SH NAME CURLOPT_DEBUGDATA \- pointer passed to the debug callback .SH SYNOPSIS .nf #include 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 All .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 Always .SH RETURN VALUE Returns CURLE_OK .SH SEE ALSO .BR CURLOPT_DEBUGFUNCTION (3), .BR CURLOPT_STDERR (3)