<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <meta http-equiv="X-UA-Compatible" content="IE=9"/> <meta name="generator" content="Doxygen 1.8.14"/> <meta name="viewport" content="width=device-width, initial-scale=1"/> <title>json-c: `json-c`</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="dynsections.js"></script> <link href="doxygen.css" rel="stylesheet" type="text/css" /> </head> <body> <div id="top"><!-- do not remove this div, it is closed by doxygen! --> <div id="titlearea"> <table cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 56px;"> <td id="projectalign" style="padding-left: 0.5em;"> <div id="projectname">json-c  <span id="projectnumber">0.13.1</span> </div> </td> </tr> </tbody> </table> </div> <!-- end header part --> <!-- Generated by Doxygen 1.8.14 --> <script type="text/javascript" src="menudata.js"></script> <script type="text/javascript" src="menu.js"></script> <script type="text/javascript"> /* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */ $(function() { initMenu('',false,false,'search.php','Search'); }); /* @license-end */</script> <div id="main-nav"></div> </div><!-- top --> <div class="header"> <div class="headertitle"> <div class="title">`json-c` </div> </div> </div><!--header--> <div class="contents"> <div class="textblock"><ol type="1"> <li><a href="#overview">Overview and Build Status</a></li> <li><a href="#buildunix">Building on Unix</a></li> <li><a href="#installprereq">Install Prerequisites</a></li> <li><a href="#buildthreaded">Building with partial threading support</a></li> <li><a href="#linking">Linking to libjson-c</a></li> <li><a href="#using">Using json-c</a></li> </ol> <h2>JSON-C - A JSON implementation in C <a class="anchor" id="overview"></a> </h2> <p>Build Status</p><ul> <li><a href="https://ci.appveyor.com/project/hawicz/json-c">AppVeyor Build</a> <div class="image"> <img src="https://ci.appveyor.com/api/projects/status/github/json-c/json-c?branch=master&svg=true" alt="AppVeyor Build Status"/> </div> </li> <li><a href="https://travis-ci.org/json-c/json-c">Travis Build</a> <div class="image"> <img src="https://travis-ci.org/json-c/json-c.svg?branch=master" alt="Travis Build Status"/> </div> </li> </ul> <p>JSON-C implements a reference counting object model that allows you to easily construct JSON objects in C, output them as JSON formatted strings and parse JSON formatted strings back into the C representation of JSON objects. It aims to conform to <a href="https://tools.ietf.org/html/rfc7159">RFC 7159</a>.</p> <h2>Building on Unix with <code>git</code>, <code>gcc</code> and <code>autotools</code> <a class="anchor" id="buildunix"></a> </h2> <p>Home page for json-c: <a href="https://github.com/json-c/json-c/wiki">https://github.com/json-c/json-c/wiki</a></p> <h3>Prerequisites:</h3> <p>See also the "Installing prerequisites" section below.</p> <ul> <li><code>gcc</code>, <code>clang</code>, or another C compiler</li> <li><code>libtool>=2.2.6b</code></li> </ul> <p>If you're not using a release tarball, you'll also need:</p> <ul> <li><code>autoconf>=2.64</code> (<code>autoreconf</code>)</li> <li><code>automake>=1.13</code></li> </ul> <p>Make sure you have a complete <code>libtool</code> install, including <code>libtoolize</code>.</p> <p>To generate docs (e.g. as part of make distcheck) you'll also need:</p><ul> <li><code>doxygen>=1.8.13</code></li> </ul> <h3>Build instructions:</h3> <p><code>json-c</code> GitHub repo: <a href="https://github.com/json-c/json-c">https://github.com/json-c/json-c</a></p> <div class="fragment"><div class="line">$ git clone https://github.com/json-c/json-c.git</div><div class="line">$ cd json-c</div><div class="line">$ sh autogen.sh</div></div><!-- fragment --><p>followed by</p> <div class="fragment"><div class="line">$ ./configure # --enable-threading</div><div class="line">$ make</div><div class="line">$ make install</div></div><!-- fragment --><p>To build and run the test programs:</p> <div class="fragment"><div class="line">$ make check</div><div class="line">$ make USE_VALGRIND=0 check # optionally skip using valgrind</div></div><!-- fragment --><h2>Install prerequisites <a class="anchor" id="installprereq"></a> </h2> <p>If you are on a relatively modern system, you'll likely be able to install the prerequisites using your OS's packaging system. <br /> ### Install using apt (e.g. Ubuntu 16.04.2 LTS) </p><div class="fragment"><div class="line">sudo apt install git</div><div class="line">sudo apt install autoconf automake libtool</div><div class="line">sudo apt install valgrind # optional</div></div><!-- fragment --><p>Then start from the "git clone" command, above.</p> <h3>Manually install and build autoconf, automake and libtool</h3> <p>For older OS's that don't have up-to-date version of the packages will require a bit more work. For example, CentOS release 5.11, etc...</p> <div class="fragment"><div class="line">curl -O http://ftp.gnu.org/gnu/autoconf/autoconf-2.69.tar.gz</div><div class="line">curl -O http://ftp.gnu.org/gnu/automake/automake-1.15.tar.gz</div><div class="line">curl -O http://ftp.gnu.org/gnu/libtool/libtool-2.2.6b.tar.gz</div><div class="line"></div><div class="line">tar xzf autoconf-2.69.tar.gz</div><div class="line">tar xzf automake-1.15.tar.gz</div><div class="line">tar xzf libtool-2.2.6b.tar.gz</div><div class="line"></div><div class="line">export PATH=${HOME}/ac_install/bin:$PATH</div><div class="line"></div><div class="line">(cd autoconf-2.69 && \</div><div class="line"> ./configure --prefix ${HOME}/ac_install && \</div><div class="line"> make && \</div><div class="line"> make install)</div><div class="line"></div><div class="line">(cd automake-1.15 && \</div><div class="line"> ./configure --prefix ${HOME}/ac_install && \</div><div class="line"> make && \</div><div class="line"> make install)</div><div class="line"></div><div class="line">(cd libtool-2.2.6b && \</div><div class="line"> ./configure --prefix ${HOME}/ac_install && \</div><div class="line"> make && \</div><div class="line"> make install)</div></div><!-- fragment --><h2>Building with partial threading support <a class="anchor" id="buildthreaded"></a> </h2> <p>Although json-c does not support fully multi-threaded access to object trees, it has some code to help make use in threaded programs a bit safer. Currently, this is limited to using atomic operations for <a class="el" href="json__object_8h.html#a675aa3a9cced685dbfd1c1a770a0c3e4">json_object_get()</a> and <a class="el" href="json__object_8h.html#afabf61f932cd64a4122ca8092452eed5">json_object_put()</a>.</p> <p>Since this may have a performance impact, of at least 3x slower according to <a href="https://stackoverflow.com/a/11609063,">https://stackoverflow.com/a/11609063,</a> it is disabled by default. You may turn it on by adjusting your configure command with: –enable-threading</p> <p>Separately, the default hash function used for object field keys, lh_char_hash, uses a compare-and-swap operation to ensure the randomly seed is only generated once. Because this is a one-time operation, it is always compiled in when the compare-and-swap operation is available.</p> <h2>Linking to <code>libjson-c</code> <a class="anchor" id="linking"></a> </h2> <p>If your system has <code>pkgconfig</code>, then you can just add this to your <code>makefile</code>:</p> <div class="fragment"><div class="line">CFLAGS += $(shell pkg-config --cflags json-c)</div><div class="line">LDFLAGS += $(shell pkg-config --libs json-c)</div></div><!-- fragment --><p>Without <code>pkgconfig</code>, you would do something like this:</p> <div class="fragment"><div class="line">JSON_C_DIR=/path/to/json_c/install</div><div class="line">CFLAGS += -I$(JSON_C_DIR)/include/json-c</div><div class="line">LDFLAGS+= -L$(JSON_C_DIR)/lib -ljson-c</div></div><!-- fragment --><h2>Using json-c <a class="anchor" id="using"></a> </h2> <p>To use json-c you can either include <a class="el" href="json_8h.html" title="A convenience header that may be included instead of other individual ones. ">json.h</a>, or preferrably, one of the following more specific header files:</p> <ul> <li><a class="el" href="json__object_8h.html" title="Core json-c API. Start here, or with json_tokener.h. ">json_object.h</a> - Core types and methods.</li> <li><a class="el" href="json__tokener_8h.html" title="Methods to parse an input string into a tree of json_object objects. ">json_tokener.h</a> - Methods for parsing and serializing json-c object trees.</li> <li><a class="el" href="json__pointer_8h.html" title="JSON Pointer (RFC 6901) implementation for retrieving objects from a json-c object tree...">json_pointer.h</a> - JSON Pointer (RFC 6901) implementation for retrieving objects from a json-c object tree.</li> <li><a class="el" href="json__object__iterator_8h.html" title="An API for iterating over json_type_object objects, styled to be familiar to C++ programmers. Unlike json_object_object_foreach() and json_object_object_foreachC(), this avoids the need to expose json-c internals like lh_entry. ">json_object_iterator.h</a> - Methods for iterating over single <a class="el" href="structjson__object.html">json_object</a> instances.</li> <li><a class="el" href="json__visit_8h.html" title="Methods for walking a tree of objects. ">json_visit.h</a> - Methods for walking a tree of json-c objects.</li> <li><a class="el" href="json__util_8h.html" title="Miscllaneous utility functions and macros. ">json_util.h</a> - Miscelleanous utility functions.</li> </ul> <p>For a full list of headers see <a href="files.html">files.html</a> </p> </div></div><!-- contents --> <!-- start footer part --> <hr class="footer"/><address class="footer"><small> Generated on Wed Sep 26 2018 02:36:17 for json-c by  <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/> </a> 1.8.14 </small></address> </body> </html>