CURLOPT_TCP_KEEPIDLE(3) Library Functions Manual CURLOPT_TCP_KEEPIDLE(3)
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
60
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
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_KEEPCNT(3), CURLOPT_TCP_KEEP-
INTVL(3)
libcurl 2026-07-12 CURLOPT_TCP_KEEPIDLE(3)
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