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Updated: Thursday, June 13, 2019
 
 

curl_easy_upkeep (3)

Name

curl_easy_upkeep - Perform any connection upkeep checks.

Synopsis

#include <curl/curl.h>

CURLcode curl_easy_upkeep(CURL *handle);

Description

curl_easy_upkeep(3)             libcurl Manual             curl_easy_upkeep(3)



NAME
       curl_easy_upkeep - Perform any connection upkeep checks.

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_upkeep(CURL *handle);

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 overzeal-
       ous firewalls, for example.

       Currently the only protocol  with  a  connection  upkeep  mechanism  is
       HTTP/2:   when   the   connection   upkeep  interval  is  exceeded  and
       curl_easy_upkeep(3) is called, an HTTP/2 PING frame is sent on the con-
       nection.

       This  function must be explicitly called in order to perform the upkeep
       work.  The connection upkeep interval is set with CURLOPT_UPKEEP_INTER-
       VAL_MS(3).


AVAILABILITY
       Added in 7.62.0.

RETURN VALUE
       On success, returns CURLE_OK.

       On failure, returns the appropriate error code.


EXAMPLE
       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);
       }




ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | web/curl         |
       +---------------+------------------+
       |Stability      | Uncommitted      |
       +---------------+------------------+
NOTES
       This     software     was    built    from    source    available    at
       https://github.com/oracle/solaris-userland.   The  original   community
       source    was    downloaded    from    https://github.com/curl/curl/ar-
       chive/curl-7_64_0.zip

       Further information about this software can be found on the open source
       community website at http://curl.haxx.se/.



libcurl 7.62.0                    31 Oct 2018              curl_easy_upkeep(3)