curl_multi_setopt(3)

NAME

       curl_multi_setopt - set options for a curl multi handle

SYNOPSIS

       #include <curl/curl.h>

       CURLMcode  curl_multi_setopt(CURLM  * multi_handle, CURLMoption option,
       param);

DESCRIPTION

       curl_multi_setopt() is used to tell  a  libcurl  multi  handle  how  to
       behave.  By  using the appropriate options to curl_multi_setopt(3), you
       can change libcurl's behaviour  when  using  that  multi  handle.   All
       options  are  set with the option followed by the parameter param. That
       parameter can be a long, a function pointer, an  object  pointer  or  a
       curl_off_t  type,  depending  on what the specific option expects. Read
       this manual carefully as bad input values may cause libcurl  to  behave
       badly!  You can only set one option in each function call.

OPTIONS

       CURLMOPT_SOCKETFUNCTION
              Pass  a  pointer to a function matching the curl_socket_callback
              prototype. The curl_multi_socket(3) functions inform the  appli-
              cation  about  updates in the socket (file descriptor) status by
              doing none, one or multiple calls  to  the  curl_socket_callback
              given in the param argument. They update the status with changes
              since the previous  time  a  curl_multi_socket(3)  function  was
              called.  If the given callback pointer is NULL, no callback will
              be called. Set the callback's userp argument with CURLMOPT_SOCK-
              ETDATA.  See curl_multi_socket(3) for more callback details.

       CURLMOPT_SOCKETDATA
              Pass   a   pointer   to   whatever   you   want  passed  to  the
              curl_socket_callback's forth argument, the userp  pointer.  This
              is not used by libcurl but only passed-thru as-is. Set the call-
              back pointer with CURLMOPT_SOCKETFUNCTION.

       CURLMOPT_PIPELINING
              Pass a long set to  1  to  enable  or  0  to  disable.  Enabling
              pipelining  on  a  multi  handle will make it attempt to perform
              HTTP Pipelining as far as possible for transfers using this han-
              dle. This means that if you add a second request that can use an
              already existing connection, the second request will be  "piped"
              on  the same connection rather than being executed in parallell.
              (Added in 7.16.0)

       CURLMOPT_TIMERFUNCTION
              Pass a pointer to a function matching the curl_multi_timer_call-
              back  prototype.   This  function  will  then be called when the
              timeout value changes. The timeout value is at what latest  time
              the application should call one of the "performing" functions of
              the        multi        interface         (curl_multi_socket(3),
              curl_multi_socket_all(3)  and  curl_multi_perform(3)) - to allow
              libcurl to keep  timeouts  and  retries  etc  to  work.  Libcurl
              attempts  to limit calling this only when the fixed future time-
              out time actually  change.  See  also  CURLMOPT_TIMERDATA.  This
              callback   can   be   used   instead  of,  or  in  addition  to,
              curl_multi_timeout(3). (Added in 7.16.0)

       CURLMOPT_TIMERDATA
              Pass  a  pointer  to   whatever   you   want   passed   to   the
              curl_multi_timer_callback's  third  argument, the userp pointer.
              This is not used by libcurl but only passed-thru as-is. Set  the
              callback pointer with CURLMOPT_TIMERFUNCTION. (Added in 7.16.0)

       CURLMOPT_MAXCONNECTS
              Pass  a  long. The set number will be used as the maximum amount
              of simultaneously  open  connections  that  libcurl  may  cache.
              Default  is 10, and libcurl will enlarge the size for each added
              easy handle to make it fit 4 times the number of added easy han-
              dles.

              By  setting  this option, you can prevent the cache size to grow
              beyond the limit set by you.

              When the cache is full, curl closes the oldest one in the  cache
              to prevent the number of open connections to increase.

              This  option  is for the multi handle's use only, when using the
              easy interface you should instead  use  the  CURLOPT_MAXCONNECTS
              option.

              (Added in 7.16.3)

RETURNS

       The  standard  CURLMcode  for multi interface error codes. Note that it
       returns a CURLM_UNKNOWN_OPTION if you try setting an option  that  this
       version of libcurl doesn't know of.

AVAILABILITY

       This function was added in libcurl 7.15.4.

SEE ALSO

       curl_multi_cleanup(3),     curl_multi_init(3),    curl_multi_socket(3),
       curl_multi_info_read(3)

libcurl 7.16.0                    10 Oct 2006             curl_multi_setopt(3)