CURLOPT_TCP_KEEPCNT - Man Page

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_KEEPCNT, long cnt);

Pass a long. Sets the number of probes to send before dropping the connection. Not all operating systems support this option. (Added in 8.9.0)

The maximum value this option accepts is INT_MAX or whatever your system allows. Any larger value is capped to this amount.

9

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 8.9.0

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).

CURLOPT_TCP_KEEPALIVE(3), CURLOPT_TCP_KEEPIDLE(3), CURLOPT_TCP_KEEPINTVL(3)

curl_easy_setopt(3), CURLOPT_TCP_KEEPALIVE(3), CURLOPT_TCP_KEEPIDLE(3), CURLOPT_TCP_KEEPINTVL(3), libcurl-symbols(3).