.\" generated by cd2nroff 0.1 from CURLOPT_CLOSESOCKETDATA.md .TH CURLOPT_CLOSESOCKETDATA 3 "2025-02-13" libcurl .SH NAME CURLOPT_CLOSESOCKETDATA \- pointer passed to the socket close callback .SH SYNOPSIS .nf #include CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CLOSESOCKETDATA, void *pointer); .fi .SH DESCRIPTION Pass a \fIpointer\fP that remains untouched by libcurl and passed as the first argument in the closesocket callback set with \fICURLOPT_CLOSESOCKETFUNCTION(3)\fP. .SH DEFAULT NULL .SH PROTOCOLS This functionality affects all supported protocols .SH EXAMPLE .nf struct priv { void *custom; }; static int closesocket(void *clientp, curl_socket_t item) { struct priv *my = clientp; printf("our ptr: %p\\n", my->custom); printf("libcurl wants to close %d now\\n", (int)item); return 0; } int main(void) { struct priv myown; CURL *curl = curl_easy_init(); /* call this function to close sockets */ curl_easy_setopt(curl, CURLOPT_CLOSESOCKETFUNCTION, closesocket); curl_easy_setopt(curl, CURLOPT_CLOSESOCKETDATA, &myown); curl_easy_perform(curl); curl_easy_cleanup(curl); } .fi .SH AVAILABILITY Added in curl 7.21.7 .SH RETURN VALUE \fIcurl_easy_setopt(3)\fP returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non\-zero means an error occurred, see \fIlibcurl\-errors(3)\fP. .SH SEE ALSO .BR CURLOPT_CLOSESOCKETFUNCTION (3), .BR CURLOPT_OPENSOCKETFUNCTION (3)