mirror of
https://github.com/moparisthebest/curl
synced 2024-11-17 23:15:08 -05:00
78 lines
2.7 KiB
Groff
78 lines
2.7 KiB
Groff
.\" **************************************************************************
|
|
.\" * _ _ ____ _
|
|
.\" * Project ___| | | | _ \| |
|
|
.\" * / __| | | | |_) | |
|
|
.\" * | (__| |_| | _ <| |___
|
|
.\" * \___|\___/|_| \_\_____|
|
|
.\" *
|
|
.\" * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
|
|
.\" *
|
|
.\" * This software is licensed as described in the file COPYING, which
|
|
.\" * you should have received as part of this distribution. The terms
|
|
.\" * are also available at https://curl.haxx.se/docs/copyright.html.
|
|
.\" *
|
|
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
|
.\" * copies of the Software, and permit persons to whom the Software is
|
|
.\" * furnished to do so, under the terms of the COPYING file.
|
|
.\" *
|
|
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
.\" * KIND, either express or implied.
|
|
.\" *
|
|
.\" **************************************************************************
|
|
.\"
|
|
.TH curl_easy_upkeep 3 "31 Oct 2018" "libcurl 7.62.0" "libcurl Manual"
|
|
.SH NAME
|
|
curl_easy_upkeep - Perform any connection upkeep checks.
|
|
.SH SYNOPSIS
|
|
.B #include <curl/curl.h>
|
|
|
|
.BI "CURLcode curl_easy_upkeep(CURL *" handle ");"
|
|
.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.
|
|
|
|
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.
|
|
|
|
This function must be explicitly called in order to perform the upkeep work.
|
|
The connection upkeep interval is set with
|
|
\fICURLOPT_UPKEEP_INTERVAL_MS(3)\fP.
|
|
|
|
.SH AVAILABILITY
|
|
Added in 7.62.0.
|
|
.SH RETURN VALUE
|
|
On success, returns \fBCURLE_OK\fP.
|
|
|
|
On failure, returns the appropriate error code.
|
|
|
|
.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
|