curl/docs/libcurl/opts/CURLOPT_UPKEEP_INTERVAL_MS.3
Daniel Stenberg 12a2ed970f
opt-docs: verify man page sections + order
In every libcurl option man page there are now 8 mandatory sections that
must use the right name in the correct order and test 1173 verifies
this. Only 14 man pages needed adjustments.

The sections and the order is as follows:

 - NAME
 - SYNOPSIS
 - DESCRIPTION
 - PROTOCOLS
 - EXAMPLE
 - AVAILABILITY
 - RETURN VALUE
 - SEE ALSO

Reviewed-by: Daniel Gustafsson
Closes #7656
2021-09-04 11:27:46 +02:00

79 lines
2.8 KiB
Groff

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.TH CURLOPT_UPKEEP_INTERVAL_MS 3 "31 Oct 2018" "libcurl 7.62.0" "curl_easy_setopt options"
.SH NAME
CURLOPT_UPKEEP_INTERVAL_MS \- connection upkeep interval
.SH SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UPKEEP_INTERVAL_MS, long upkeep_interval_ms);
.SH DESCRIPTION
Some protocols have "connection upkeep" mechanisms. These mechanisms usually
send some traffic on existing connections in order to keep them alive; this
can prevent connections from being closed due to overzealous firewalls, for
example.
The user needs to explicitly call \fIcurl_easy_upkeep(3)\fP in order to
perform the upkeep work.
Currently the only protocol with a connection upkeep mechanism is HTTP/2: when
the connection upkeep interval is exceeded and \fIcurl_easy_upkeep(3)\fP
is called, an HTTP/2 PING frame is sent on the connection.
.SH DEFAULT
CURL_UPKEEP_INTERVAL_DEFAULT (currently defined as 60000L, which is 60 seconds)
.SH PROTOCOLS
All
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
if(curl) {
/* Make a connection to an HTTP/2 server. */
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
/* Set the interval to 30000ms / 30s */
curl_easy_setopt(curl, CURLOPT_UPKEEP_INTERVAL_MS, 30000L);
curl_easy_perform(curl);
/* Perform more work here. */
/* While the connection is being held open, curl_easy_upkeep() can be
called. If curl_easy_upkeep() is called and the time since the last
upkeep exceeds the interval, then an HTTP/2 PING is sent. */
curl_easy_upkeep(curl);
/* Perform more work here. */
/* always cleanup */
curl_easy_cleanup(curl);
}
.fi
.SH AVAILABILITY
Added in 7.62.0
.SH RETURN VALUE
Returns CURLE_OK
.SH SEE ALSO
.BR CURLOPT_TCP_KEEPALIVE "(3), "