CURLOPT_TCP_KEEPCNT(3)     Library Functions Manual     CURLOPT_TCP_KEEPCNT(3)

NAME
       CURLOPT_TCP_KEEPCNT - Maximum number of TCP keep-alive probes

SYNOPSIS
       #include <curl/curl.h>

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

DESCRIPTION
       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.

DEFAULT
       9

PROTOCOLS
       This functionality affects tcp only

EXAMPLE
       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode result;
           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);

           result = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY
       Added in curl 8.9.0

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).

SEE ALSO
       CURLOPT_TCP_KEEPALIVE(3), CURLOPT_TCP_KEEPIDLE(3),
       CURLOPT_TCP_KEEPINTVL(3)

libcurl                           2026-09-02            CURLOPT_TCP_KEEPCNT(3)