CURLOPT_TCP_KEEPIDLE - Man Page

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_KEEPIDLE, long delay);

Pass a long. Sets the delay, in seconds, to wait while the connection is idle before sending keepalive probes. Not all operating systems support this option.

The maximum value this accepts is 2147483648. Any larger value is capped to this amount.

60

This functionality affects tcp only

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);

    /* set 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);
  }
}

Added in curl 7.25.0

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

CURLOPT_TCP_KEEPALIVE(3), CURLOPT_TCP_KEEPCNT(3), CURLOPT_TCP_KEEPINTVL(3)

curl_easy_setopt(3), curl_easy_upkeep(3), CURLOPT_TCP_KEEPALIVE(3), CURLOPT_TCP_KEEPCNT(3), CURLOPT_TCP_KEEPINTVL(3), libcurl-symbols(3).