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Sortix volatile manual

This manual documents Sortix volatile, a development build that has not been officially released. You can instead view this document in the latest official manual.

CURLMOPT_SOCKETDATA(3) Library Functions Manual CURLMOPT_SOCKETDATA(3)

NAME

CURLMOPT_SOCKETDATA - custom pointer passed to the socket callback

SYNOPSIS


#include <curl/curl.h>

CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETDATA, void *pointer);

DESCRIPTION

A data pointer to pass to the socket callback set with the CURLMOPT_SOCKETFUNCTION(3) option.
 
This pointer is not touched by libcurl but is only passed in as the socket callback's clientp argument.

DEFAULT

NULL

PROTOCOLS

This functionality affects all supported protocols

EXAMPLE


struct priv {
void *ours;
};

static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
{
struct priv *p = sockp;
printf("my ptr: %p\n", p->ours);

if(what == CURL_POLL_REMOVE) {
/* remove the socket from our collection */
}
if(what & CURL_POLL_IN) {
/* wait for read on this socket */
}
if(what & CURL_POLL_OUT) {
/* wait for write on this socket */
}

return 0;
}

int main(void)
{
struct priv setup;
CURLM *multi = curl_multi_init();
/* ... use socket callback and custom pointer */
curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, &setup);
}

AVAILABILITY

Added in curl 7.15.4

RETURN VALUE

Returns CURLM_OK.

SEE ALSO

CURLMOPT_SOCKETFUNCTION(3), CURLMOPT_TIMERFUNCTION(3), curl_multi_socket_action(3)
2025-05-14 libcurl
Copyright 2011-2025 Jonas 'Sortie' Termansen and contributors.
Sortix's source code is free software under the ISC license.
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