libcurl-share(3) [posix man page]

libcurl-share(3)					      libcurl share interface						  libcurl-share(3)

NAME

       libcurl-share - how to use the share interface

DESCRIPTION

       This  is an overview on how to use the libcurl share interface in your C programs. There are specific man pages for each function mentioned
       in here.

       All functions in the share interface are prefixed with curl_share.

OBJECTIVES

       The share interface was added to enable sharing of data between curl "handles".

ONE SET OF DATA - MANY TRANSFERS
       You can have multiple easy handles share data between them. Have them update and use the same cookie database or DNS cache! This way,  each
       single transfer will take advantage from data updates made by the other transfer(s).

SHARE OBJECT

       You create a shared object with curl_share_init(3). It returns a handle for a newly created one.

       You  tell  the  shared  object what data you want it to share by using curl_share_setopt(3). Currently you can only share DNS and/or COOKIE
       data.

       Since you can use this share from multiple threads, and libcurl has no internal thread synchronization, you must provide mutex callbacks if
       you're using this multi-threaded. You set lock and unlock functions with curl_share_setopt(3) too.

       Then,  you  make an easy handle to use this share, you set the CURLOPT_SHARE option with curl_easy_setopt(3), and pass in share handle. You
       can make any number of easy handles share the same share handle.

       To make an easy handle stop using that particular share, you set CURLOPT_SHARE to NULL for that easy handle. To make a handle stop  sharing
       a particular data, you can CURLSHOPT_UNSHARE it.

       When you're done using the share, make sure that no easy handle is still using it, and call curl_share_cleanup(3) on the handle.

SEE ALSO

       curl_share_init(3), curl_share_setopt(3), curl_share_cleanup(3)

libcurl 7.10.7							    8 Aug 2003							  libcurl-share(3)

curl_share_setopt(3)						  libcurl Manual					      curl_share_setopt(3)

NAME

       curl_share_setopt - Set options for a shared object

SYNOPSIS

       #include <curl/curl.h>

       CURLSHcode curl_share_setopt(CURLSH *share, CURLSHoption option, parameter);

DESCRIPTION

       Set the option to parameter for the given share.

OPTIONS

       CURLSHOPT_LOCKFUNC
	      The parameter must be a pointer to a function matching the following prototype:

	      void lock_function(CURL *handle, curl_lock_data data, curl_lock_access access, void *userptr);

	      data defines what data libcurl wants to lock, and you must make sure that only one lock is given at any time for each kind of data.

	      access defines what access type libcurl wants, shared or single.

	      userptr is the pointer you set with CURLSHOPT_USERDATA.

       CURLSHOPT_UNLOCKFUNC
	      The parameter must be a pointer to a function matching the following prototype:

	      void unlock_function(CURL *handle, curl_lock_data data, void *userptr);

	      data  defines  what  data  libcurl  wants to unlock, and you must make sure that only one lock is given at any time for each kind of
	      data.

	      userptr is the pointer you set with CURLSHOPT_USERDATA.

       CURLSHOPT_SHARE
	      The parameter specifies a type of data that should be shared. This may be set to one of the values described below.

	      CURL_LOCK_DATA_COOKIE
		     Cookie data will be shared across the easy handles using this shared object.

	      CURL_LOCK_DATA_DNS
		     Cached DNS hosts will be shared across the easy handles using this shared object. Note that when you use the multi interface,
		     all easy handles added to the same multi handle will share DNS cache by default without this having to be used!

	      CURL_LOCK_DATA_SSL_SESSION
		     SSL  session  IDs will be shared across the easy handles using this shared object. This will reduce the time spent in the SSL
		     handshake when reconnecting to the same server. Note SSL session IDs are reused within the same easy handle by default.

       CURLSHOPT_UNSHARE
	      This option does the opposite of CURLSHOPT_SHARE. It specifies that the specified parameter will no longer be shared.  Valid  values
	      are the same as those for CURLSHOPT_SHARE.

       CURLSHOPT_USERDATA
	      The  parameter  allows you to specify a pointer to data that will be passed to the lock_function and unlock_function each time it is
	      called.

RETURN VALUE

       CURLSHE_OK (zero) means that the option was set properly, non-zero means an error occurred  as  <curl/curl.h>  defines.	See  the  libcurl-
       errors.3 man page for the full list with descriptions.

SEE ALSO

       curl_share_cleanup(3), curl_share_init(3)

libcurl 7.10.7							    8 Aug 2003						      curl_share_setopt(3)