CURLOPT_TCP_KEEPALIVE(3) Library Functions Manual CURLOPT_TCP_KEEPALIVE(3) NAME CURLOPT_TCP_KEEPALIVE - TCP keep-alive probing SYNOPSIS #include 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) and CURLOPT_TCP_KEEPINTVL(3) options, provided the operating system supports them. Set to 0 (default behavior) to disable keepalive probes DEFAULT 0 PROTOCOLS All 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); curl_easy_perform(curl); } } AVAILABILITY Added in 7.25.0 RETURN VALUE Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. SEE ALSO CURLOPT_LOW_SPEED_LIMIT(3), CURLOPT_MAX_RECV_SPEED_LARGE(3), CURLOPT_TCP_KEEPIDLE(3), CURLOPT_TCP_KEEPINTVL(3) libcurl April 26 2024 CURLOPT_TCP_KEEPALIVE(3)