CURLOPT_TCP_KEEPIDLE

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_KEEPIDLE, long delay);

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

60

All

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);
  curl_easy_perform(curl);
}

Added in 7.25.0

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

CURLOPT_TCP_KEEPALIVE(3), CURLOPT_TCP_KEEPINTVL(3),