Tribblix: manual page: CURLOPT_TCP

CURLOPT_TCP_KEEPALIVE(3) Introduction to Library Functions

NAME

CURLOPT_TCP_KEEPALIVE - TCP keep-alive probing

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_KEEPALIVE, long probe);

DESCRIPTION

Pass a long. If set to 1, TCP keepalive probes are used. The delay
and frequency of these probes can be controlled by the
CURLOPT_TCP_KEEPIDLE(3), CURLOPT_TCP_KEEPINTVL(3), and
CURLOPT_TCP_KEEPCNT(3) options, provided the operating system
supports them. Set to 0 (default behavior) to disable keepalive
probes.

DEFAULT

PROTOCOLS

This functionality affects tcp only

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

/* enable TCP keep-alive for this transfer */
curl_easy_setopt(curl, CURLOPT_TCP_KEEPALIVE, 1L);

/* keep-alive idle time to 120 seconds */
curl_easy_setopt(curl, CURLOPT_TCP_KEEPIDLE, 120L);

/* interval time between keep-alive probes: 60 seconds */
curl_easy_setopt(curl, CURLOPT_TCP_KEEPINTVL, 60L);

/* maximum number of keep-alive probes: 3 */
curl_easy_setopt(curl, CURLOPT_TCP_KEEPCNT, 3L);

curl_easy_perform(curl);
}
}

AVAILABILITY

Added in curl 7.25.0

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).