curl / libcurl / API / curl_easy_setopt / CURLOPT_TCP_KEEPIDLE

CURLOPT_TCP_KEEPIDLE explained

Name

CURLOPT_TCP_KEEPIDLE - TCP keep-alive idle time wait

Synopsis

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

Description

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

The maximum value this accepts is 2147483648. Any larger value is capped to this amount.

Default

Protocols

This functionality affects tcp only

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);
 
    /* 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);
  }
}

Availability

Added in curl 7.25.0

Return value

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