CURLOPT_PREREQDATA(3)

NAME
CURLOPT_PREREQDATA - pointer passed to the pre-request callback

SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PREREQDATA, void *pointer);

DESCRIPTION
Pass a pointer that is untouched by libcurl and passed as the first argument in the pre-request callback set with CURLOPT_PREREQFUNCTION(3).

DEFAULT
NULL

PROTOCOLS
This functionality affects all supported protocols

EXAMPLE
struct priv {
  void *custom;
};
static int prereq_callback(void *clientp,
                           char *conn_primary_ip,
                           char *conn_local_ip,
                           int conn_primary_port,
                           int conn_local_port)
{
  printf("Connection made to %s:%d\n", conn_primary_ip, conn_primary_port);
  return CURL_PREREQFUNC_OK;
}
int main(void)
{
  struct priv prereq_data;
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_PREREQFUNCTION, prereq_callback);
    curl_easy_setopt(curl, CURLOPT_PREREQDATA, &prereq_data);
    curl_easy_perform(curl);
  }
}

AVAILABILITY
Added in curl 7.80.0

RETURN VALUE
curl_easy_setopt(3) returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

SEE ALSO
CURLINFO_PRIMARY_IP(3), CURLINFO_PRIMARY_PORT(3), CURLOPT_PREREQFUNCTION(3)