NAME

CURLOPT_TCP_KEEPALIVE - TCP keep-alive probing

SYNOPSIS

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

DESCRIPTION

Pass a long. If set to 1, TCP keepalive probes will be sent. 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

PROTOCOLS

All

EXAMPLE

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.