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.TH CURLMOPT_SOCKETDATA 3 "May 17, 2022" "libcurl 7.87.0" "curl_multi_setopt options"

.SH NAME
CURLMOPT_SOCKETDATA \- custom pointer passed to the socket callback
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETDATA, void *pointer);
.SH DESCRIPTION
A data \fIpointer\fP to pass to the socket callback set with the
\fICURLMOPT_SOCKETFUNCTION(3)\fP option.

This pointer will not be touched by libcurl but will only be passed in to the
socket callbacks's \fBuserp\fP argument.
.SH DEFAULT
NULL
.SH PROTOCOLS
All
.SH EXAMPLE
.nf
static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
{
  GlobalInfo *g = (GlobalInfo*) cbp;
  SockInfo *fdp = (SockInfo*) sockp;

  if(what == CURL_POLL_REMOVE) {
    remsock(fdp);
  }
  else {
    if(!fdp) {
      addsock(s, e, what, g);
    }
    else {
      setsock(fdp, s, e, what, g);
    }
  }
  return 0;
}

main()
{
  GlobalInfo setup;
  /* ... use socket callback and custom pointer */
  curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
  curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, &setup);
}
.fi
.SH AVAILABILITY
Added in 7.15.4
.SH RETURN VALUE
Returns CURLM_OK.
.SH "SEE ALSO"
.BR CURLMOPT_SOCKETFUNCTION "(3), " curl_multi_socket_action "(3), "
.BR CURLMOPT_TIMERFUNCTION "(3) "