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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.

CURLINFO_LASTSOCKET(3) Library Functions Manual CURLINFO_LASTSOCKET(3)

NAME

CURLINFO_LASTSOCKET - get the last socket used

SYNOPSIS


#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_LASTSOCKET, long *socket);

DESCRIPTION

Deprecated since 7.45.0. Use CURLINFO_ACTIVESOCKET(3) instead.
 
Pass a pointer to a long to receive the last socket used by this curl session. If the socket is no longer valid, -1 is returned. When you finish working with the socket, you must call curl_easy_cleanup(3) as usual and let libcurl close the socket and cleanup other resources associated with the handle. This is typically used in combination with CURLOPT_CONNECT_ONLY(3).
 
NOTE: this API is deprecated since it is not working on win64 where the SOCKET type is 64 bits large while its 'long' is 32 bits. Use the CURLINFO_ACTIVESOCKET(3) instead, if possible.

PROTOCOLS

This functionality affects all supported protocols

EXAMPLE


int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
long sockfd; /* does not work on win64 */
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_LASTSOCKET, &sockfd);
if(!res && sockfd != -1) {
/* operate on sockfd */
}

curl_easy_cleanup(curl);
}
}

AVAILABILITY

Added in curl 7.15.2

RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

CURLINFO_ACTIVESOCKET(3), CURLOPT_CONNECT_ONLY(3), curl_easy_getinfo(3), curl_easy_setopt(3)
2025-05-13 libcurl
Copyright 2011-2025 Jonas 'Sortie' Termansen and contributors.
Sortix's source code is free software under the ISC license.
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