libcurl-share - how to use the share interface


   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

   All functions in the share interface are prefixed with curl_share.


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


   You can have multiple easy handles share data between them.  Have  them
   update  and use the same cookie database, DNS cache, TLS session cache!
   This way, each single transfer will take advantage  from  data  updates
   made by the other transfer(s). The sharing interface, however, does not
   share active or persistent connections between different easy handles.


   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

   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(3) option with curl_easy_setopt(3),  and  pass  in  share
   handle.  You  can  make any number of easy handles share the same share

   To make an easy handle  stop  using  that  particular  share,  you  set
   CURLOPT_SHARE(3)  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.


   curl_share_init(3),     curl_share_setopt(3),     curl_share_cleanup(3)
   libcurl-errors(3), libcurl-easy(3), libcurl-multi(3)


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.