---
name: "CURLOPT_TCP_KEEPINTVL"
section: "3"
platform: "macos"
package: "curl"
version: "166.0.0.0.1"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLOPT_TCP_KEEPINTVL"
---

# CURLOPT\_TCP\_KEEPINTVL(3)

TCP keep-alive interval

## NAME

CURLOPT\_TCP\_KEEPINTVL - TCP keep-alive interval

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_KEEPINTVL, long interval);
```

## DESCRIPTION

Pass a long. Sets the interval, in seconds, to wait between sending keepalive probes. Not all operating systems support this option. (Added in 7.25.0)

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

## DEFAULT

60

## 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);
    /* 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);
    curl_easy_perform(curl);
  }
}
```

## AVAILABILITY

Always

## RETURN VALUE

Returns CURLE\_OK if the option is supported, and CURLE\_UNKNOWN\_OPTION if not.

## SEE ALSO

[**CURLOPT\_TCP\_KEEPALIVE**(3)](/CURLOPT_TCP_KEEPALIVE/3.md), [**CURLOPT\_TCP\_KEEPIDLE**(3)](/CURLOPT_TCP_KEEPIDLE/3.md)