curl/docs/libcurl/opts/CURLOPT_PREREQDATA.3

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.TH CURLOPT_PREREQDATA 3 "2 Aug 2021" "libcurl 7.80.0" "curl_easy_setopt options"
.SH NAME
CURLOPT_PREREQDATA \- pointer passed to the pre-request callback
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PREREQDATA, void *pointer);
.fi
.SH DESCRIPTION
Pass a \fIpointer\fP that will be untouched by libcurl and passed as the first
argument in the pre-request callback set with
\fICURLOPT_PREREQFUNCTION(3)\fP.
.SH DEFAULT
NULL
.SH PROTOCOLS
All
.SH EXAMPLE
.nf
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:%s\\n", conn_primary_ip, conn_primary_port);
  return CURL_PREREQFUNC_OK;
}

{
  struct data prereq_data;
  curl_easy_setopt(CURL *handle, CURLOPT_PREREQFUNCTION, prereq_callback);
  curl_easy_setopt(CURL *handle, CURLOPT_PREREQDATA, &prereq_data);
}
.fi
.SH AVAILABILITY
Added in 7.80.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR CURLOPT_PREREQFUNCTION "(3) "