repo/core/curl/files/CURLINFO_ACTIVESOCKET.3

.\" generated by cd2nroff 0.1 from CURLINFO_ACTIVESOCKET.md
.TH CURLINFO_ACTIVESOCKET 3 "2024-07-29" libcurl
.SH NAME
CURLINFO_ACTIVESOCKET \- get the active socket
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_ACTIVESOCKET,
                           curl_socket_t *socket);
.fi
.SH DESCRIPTION
Pass a pointer to a curl_socket_t to receive the most recently active socket
used for the transfer connection by this curl session. If the socket is no
longer valid, \fICURL_SOCKET_BAD\fP is returned. When you are finished working
with the socket, you must call \fIcurl_easy_cleanup(3)\fP as usual on the easy
handle and let libcurl close the socket and cleanup other resources associated
with the handle. This option returns the active socket only after the transfer
is complete, and is typically used in combination with
\fICURLOPT_CONNECT_ONLY(3)\fP, which skips the transfer phase.

\fICURLINFO_ACTIVESOCKET(3)\fP was added as a replacement for
\fICURLINFO_LASTSOCKET(3)\fP since that one is not working on all platforms.
.SH PROTOCOLS
This functionality affects all supported protocols
.SH EXAMPLE
.nf
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_socket_t sockfd;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

    /* Do not do the transfer - only connect to host */
    curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
    res = curl_easy_perform(curl);
    if(res != CURLE_OK) {
      printf("Error: %s\\n", curl_easy_strerror(res));
      curl_easy_cleanup(curl);
      return 1;
    }

    /* Extract the socket from the curl handle */
    res = curl_easy_getinfo(curl, CURLINFO_ACTIVESOCKET, &sockfd);
    if(!res && sockfd != CURL_SOCKET_BAD) {
      /* operate on sockfd */
    }

    curl_easy_cleanup(curl);
  }
}
.fi
.SH AVAILABILITY
Added in curl 7.45.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH SEE ALSO
.BR CURLINFO_LASTSOCKET (3),
.BR CURLOPT_CONNECT_ONLY (3),
.BR curl_easy_getinfo (3),
.BR curl_easy_setopt (3)