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 191   <div class="section" id="retrieving-data-from-the-server">
 192 <h1>Retrieving data from the server<a class="headerlink" href="#retrieving-data-from-the-server" title="Permalink to this headline">¶</a></h1>
 193 <div class="section" id="synopsis">
 194 <span id="index-0"></span><h2>SYNOPSIS<a class="headerlink" href="#synopsis" title="Permalink to this headline">¶</a></h2>
 195 <p>#include &lt;libmemcached/memcached.h&gt;</p>
 196 <dl class="cpp function">
 197 <dt id="_CPPv422memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t">
 198 <span id="_CPPv322memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t"></span><span id="_CPPv222memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t"></span><span id="memcached_fetch_result__memcached_stP.memcached_result_stP.memcached_return_tP"></span><a class="reference internal" href="memcached_result_st.html#_CPPv419memcached_result_st" title="memcached_result_st">memcached_result_st</a> *<code class="sig-name descname">memcached_fetch_result</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <a class="reference internal" href="memcached_result_st.html#_CPPv419memcached_result_st" title="memcached_result_st">memcached_result_st</a> *<em>result</em>, <a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> *<em>error</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv422memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t" title="Permalink to this definition">¶</a><br /></dt>
 199 <dd></dd></dl>
 200
 201 <dl class="cpp function">
 202 <dt id="_CPPv413memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t">
 203 <span id="_CPPv313memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t"></span><span id="_CPPv213memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t"></span><span id="memcached_get__memcached_stP.cCP.s.sP.uint32_tP.memcached_return_tP"></span>char *<code class="sig-name descname">memcached_get</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <em class="property">const</em> char *<em>key</em>, size_t <em>key_length</em>, size_t *<em>value_length</em>, uint32_t *<em>flags</em>, <a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> *<em>error</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv413memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="Permalink to this definition">¶</a><br /></dt>
 204 <dd></dd></dl>
 205
 206 <dl class="cpp function">
 207 <dt id="_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t">
 208 <span id="_CPPv314memcached_mgetP12memcached_stPPCKcPK6size_t6size_t"></span><span id="_CPPv214memcached_mgetP12memcached_stPPCKcPK6size_t6size_t"></span><span id="memcached_mget__memcached_stP.cCPCP.sCP.s"></span><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> <code class="sig-name descname">memcached_mget</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <em class="property">const</em> char *<em class="property">const</em> *<em>keys</em>, <em class="property">const</em> size_t *<em>key_length</em>, size_t <em>number_of_keys</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t" title="Permalink to this definition">¶</a><br /></dt>
 209 <dd></dd></dl>
 210
 211 <dl class="cpp function">
 212 <dt id="_CPPv420memcached_get_by_keyP12memcached_stPKc6size_tPKc6size_tP6size_tP8uint32_tP18memcached_return_t">
 213 <span id="_CPPv320memcached_get_by_keyP12memcached_stPKc6size_tPKc6size_tP6size_tP8uint32_tP18memcached_return_t"></span><span id="_CPPv220memcached_get_by_keyP12memcached_stPKc6size_tPKc6size_tP6size_tP8uint32_tP18memcached_return_t"></span><span id="memcached_get_by_key__memcached_stP.cCP.s.cCP.s.sP.uint32_tP.memcached_return_tP"></span>char *<code class="sig-name descname">memcached_get_by_key</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <em class="property">const</em> char *<em>group_key</em>, size_t <em>group_key_length</em>, <em class="property">const</em> char *<em>key</em>, size_t <em>key_length</em>, size_t *<em>value_length</em>, uint32_t *<em>flags</em>, <a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> *<em>error</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv420memcached_get_by_keyP12memcached_stPKc6size_tPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="Permalink to this definition">¶</a><br /></dt>
 214 <dd></dd></dl>
 215
 216 <dl class="cpp function">
 217 <dt id="_CPPv421memcached_mget_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_t">
 218 <span id="_CPPv321memcached_mget_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_t"></span><span id="_CPPv221memcached_mget_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_t"></span><span id="memcached_mget_by_key__memcached_stP.cCP.s.cCPCP.sCP.s"></span><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> <code class="sig-name descname">memcached_mget_by_key</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <em class="property">const</em> char *<em>group_key</em>, size_t <em>group_key_length</em>, <em class="property">const</em> char *<em class="property">const</em> *<em>keys</em>, <em class="property">const</em> size_t *<em>key_length</em>, size_t <em>number_of_keys</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv421memcached_mget_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_t" title="Permalink to this definition">¶</a><br /></dt>
 219 <dd></dd></dl>
 220
 221 <dl class="cpp function">
 222 <dt id="_CPPv423memcached_fetch_executeP12memcached_stP20memcached_execute_fnPv8uint32_t">
 223 <span id="_CPPv323memcached_fetch_executeP12memcached_stP20memcached_execute_fnPv8uint32_t"></span><span id="_CPPv223memcached_fetch_executeP12memcached_stP20memcached_execute_fnPv8uint32_t"></span><span id="memcached_fetch_execute__memcached_stP.memcached_execute_fnP.voidP.uint32_t"></span><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> <code class="sig-name descname">memcached_fetch_execute</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <a class="reference internal" href="#_CPPv420memcached_execute_fn" title="memcached_execute_fn">memcached_execute_fn</a> *<em>callback</em>, void *<em>context</em>, uint32_t <em>number_of_callbacks</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv423memcached_fetch_executeP12memcached_stP20memcached_execute_fnPv8uint32_t" title="Permalink to this definition">¶</a><br /></dt>
 224 <dd></dd></dl>
 225
 226 <dl class="cpp function">
 227 <dt id="_CPPv422memcached_mget_executeP12memcached_stPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t">
 228 <span id="_CPPv322memcached_mget_executeP12memcached_stPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t"></span><span id="_CPPv222memcached_mget_executeP12memcached_stPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t"></span><span id="memcached_mget_execute__memcached_stP.cCPCP.sCP.s.memcached_execute_fnP.voidP.uint32_t"></span><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> <code class="sig-name descname">memcached_mget_execute</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <em class="property">const</em> char *<em class="property">const</em> *<em>keys</em>, <em class="property">const</em> size_t *<em>key_length</em>, size_t <em>number_of_keys</em>, <a class="reference internal" href="#_CPPv420memcached_execute_fn" title="memcached_execute_fn">memcached_execute_fn</a> *<em>callback</em>, void *<em>context</em>, uint32_t <em>number_of_callbacks</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv422memcached_mget_executeP12memcached_stPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t" title="Permalink to this definition">¶</a><br /></dt>
 229 <dd></dd></dl>
 230
 231 <dl class="cpp function">
 232 <dt id="_CPPv429memcached_mget_execute_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t">
 233 <span id="_CPPv329memcached_mget_execute_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t"></span><span id="_CPPv229memcached_mget_execute_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t"></span><span id="memcached_mget_execute_by_key__memcached_stP.cCP.s.cCPCP.sCP.s.memcached_execute_fnP.voidP.uint32_t"></span><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> <code class="sig-name descname">memcached_mget_execute_by_key</code><span class="sig-paren">(</span><a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *<em>ptr</em>, <em class="property">const</em> char *<em>group_key</em>, size_t <em>group_key_length</em>, <em class="property">const</em> char *<em class="property">const</em> *<em>keys</em>, <em class="property">const</em> size_t *<em>key_length</em>, size_t <em>number_of_keys</em>, <a class="reference internal" href="#_CPPv420memcached_execute_fn" title="memcached_execute_fn">memcached_execute_fn</a> *<em>callback</em>, void *<em>context</em>, uint32_t <em>number_of_callbacks</em><span class="sig-paren">)</span><a class="headerlink" href="#_CPPv429memcached_mget_execute_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t" title="Permalink to this definition">¶</a><br /></dt>
 234 <dd></dd></dl>
 235
 236 <dl class="cpp type">
 237 <dt id="_CPPv420memcached_execute_fn">
 238 <span id="_CPPv320memcached_execute_fn"></span><span id="_CPPv220memcached_execute_fn"></span><span id="memcached_execute_fn"></span><em class="property">typedef </em><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t">memcached_return_t</a> (*<code class="sig-name descname">memcached_execute_fn</code>)<span class="sig-paren">(</span><em class="property">const</em> <a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st">memcached_st</a> *ptr, <a class="reference internal" href="memcached_result_st.html#_CPPv419memcached_result_st" title="memcached_result_st">memcached_result_st</a> *result, void *context<span class="sig-paren">)</span><a class="headerlink" href="#_CPPv420memcached_execute_fn" title="Permalink to this definition">¶</a><br /></dt>
 239 <dd></dd></dl>
 240
 241 <p>Compile and link with -lmemcached</p>
 242 </div>
 243 <div class="section" id="description">
 244 <h2>DESCRIPTION<a class="headerlink" href="#description" title="Permalink to this headline">¶</a></h2>
 245 <p><a class="reference internal" href="#_CPPv413memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="memcached_get"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_get()</span></code></a> is used to fetch an individual value from the server.
 246 You must pass in a key and its length to fetch the object. You must supply
 247 three pointer variables which will give you the state of the returned
 248 object.  A <code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">uint32_t</span></code> pointer to contain whatever flags you stored with the value, a <code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">size_t</span></code> pointer which will be filled with size of of
 249 the object, and a <a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_return_t</span></code></a> pointer to hold any error. The
 250 object will be returned upon success and NULL will be returned on failure. Any
 251 object returned by <a class="reference internal" href="#_CPPv413memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="memcached_get"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_get()</span></code></a> must be released by the caller
 252 application.</p>
 253 <p><a class="reference internal" href="#_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t" title="memcached_mget"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget()</span></code></a> is used to select multiple keys at once. For
 254 multiple key operations it is always faster to use this function. This function always works asynchronously.</p>
 255 <p>To retrieve data after a successful execution of <a class="reference internal" href="#_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t" title="memcached_mget"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget()</span></code></a>, you will need to
 256 call <a class="reference internal" href="#_CPPv422memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t" title="memcached_fetch_result"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_fetch_result()</span></code></a>.  You should continue to call this function until
 257 it returns a NULL (i.e. no more values). If you need to quit in the middle of a
 258 <a class="reference internal" href="#_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t" title="memcached_mget"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget()</span></code></a> call, you can execute a <a class="reference internal" href="memcached_quit.html#_CPPv414memcached_quitP12memcached_st" title="memcached_quit"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_quit()</span></code></a>, those this is not required.</p>
 259 <p><a class="reference internal" href="#_CPPv422memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t" title="memcached_fetch_result"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_fetch_result()</span></code></a> is used to fetch an individual value from the server. <a class="reference internal" href="#_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t" title="memcached_mget"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget()</span></code></a> must always be called before using this method.
 260 You must pass in a key and its length to fetch the object. You must supply
 261 three pointer variables which will give you the state of the returned
 262 object.  A <code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">uint32_t</span></code> pointer to contain whatever flags you stored with the value, a <code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">size_t</span></code> pointer which will be filled with size of of the
 263 object, and a <a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_return_t</span></code></a> pointer to hold any error. The
 264 object will be returned upon success and NULL will be returned on failure. <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t13MEMCACHED_ENDE" title="MEMCACHED_END"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_END</span></code></a> is returned by the *error value when all objects that have been found are returned. The final value upon <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t13MEMCACHED_ENDE" title="MEMCACHED_END"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_END</span></code></a> is null.</p>
 265 <p><a class="reference internal" href="#_CPPv422memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t" title="memcached_fetch_result"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_fetch_result()</span></code></a> is used to return a <a class="reference internal" href="memcached_result_st.html#_CPPv419memcached_result_st" title="memcached_result_st"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_result_st</span></code></a> structure from a memcached server. The result object is forward compatible
 266 with changes to the server. For more information please refer to the
 267 <a class="reference internal" href="memcached_result_st.html#_CPPv419memcached_result_st" title="memcached_result_st"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_result_st</span></code></a> help. This function will dynamically allocate a
 268 result structure for you if you do not pass one to the function.</p>
 269 <p><a class="reference internal" href="#_CPPv423memcached_fetch_executeP12memcached_stP20memcached_execute_fnPv8uint32_t" title="memcached_fetch_execute"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_fetch_execute()</span></code></a> is a callback function for result sets.
 270 Instead of returning the results to you for processing, it passes each of the
 271 result sets to the list of functions you provide. It passes to the function
 272 a <a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_st</span></code></a> that can be cloned for use in the called
 273 function (it can not be used directly). It also passes a result set which does
 274 not need to be freed. Finally it passes a &quot;context&quot;. This is just a pointer to
 275 a memory reference you supply the calling function. Currently only one value
 276 is being passed to each function call. In the future there will be an option
 277 to allow this to be an array.</p>
 278 <p><a class="reference internal" href="#_CPPv422memcached_mget_executeP12memcached_stPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t" title="memcached_mget_execute"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget_execute()</span></code></a> and <a class="reference internal" href="#_CPPv429memcached_mget_execute_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t" title="memcached_mget_execute_by_key"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget_execute_by_key()</span></code></a>
 279 is similar to <a class="reference internal" href="#_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t" title="memcached_mget"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget()</span></code></a>, but it may trigger the supplied
 280 callbacks with result sets while sending out the queries. If you try to
 281 perform a really large multiget with <a class="reference internal" href="#_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t" title="memcached_mget"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget()</span></code></a> you may
 282 encounter a deadlock in the OS kernel (it will fail to write data to the
 283 socket because the input buffer is full). <a class="reference internal" href="#_CPPv422memcached_mget_executeP12memcached_stPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t" title="memcached_mget_execute"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget_execute()</span></code></a>
 284 solves this problem by processing some of the results before continuing
 285 sending out requests. Please note that this function is only available in
 286 the binary protocol.</p>
 287 <p><a class="reference internal" href="#_CPPv420memcached_get_by_keyP12memcached_stPKc6size_tPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="memcached_get_by_key"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_get_by_key()</span></code></a> and <a class="reference internal" href="#_CPPv421memcached_mget_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_t" title="memcached_mget_by_key"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget_by_key()</span></code></a> behave
 288 in a similar nature as <a class="reference internal" href="#_CPPv413memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="memcached_get"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_get()</span></code></a> and <a class="reference internal" href="#_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t" title="memcached_mget"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_mget()</span></code></a>.
 289 The difference is that they take a master key that is used for determining
 290 which server an object was stored if key partitioning was used for storage.</p>
 291 <p>All of the above functions are not tested when the
 292 <code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_BEHAVIOR_USE_UDP</span></code> has been set. Executing any of these
 293 functions with this behavior on will result in <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t23MEMCACHED_NOT_SUPPORTEDE" title="MEMCACHED_NOT_SUPPORTED"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_NOT_SUPPORTED</span></code></a> being returned, or for those functions which do not return a <a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t"><code class="xref cpp cpp-type docutils literal notranslate"><span class="pre">memcached_return_t</span></code></a>, the error function parameter will be set to <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t23MEMCACHED_NOT_SUPPORTEDE" title="MEMCACHED_NOT_SUPPORTED"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_NOT_SUPPORTED</span></code></a>.</p>
 294 </div>
 295 <div class="section" id="return-value">
 296 <h2>RETURN VALUE<a class="headerlink" href="#return-value" title="Permalink to this headline">¶</a></h2>
 297 <p>All objects retrieved via <a class="reference internal" href="#_CPPv413memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="memcached_get"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_get()</span></code></a> or <a class="reference internal" href="#_CPPv420memcached_get_by_keyP12memcached_stPKc6size_tPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="memcached_get_by_key"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_get_by_key()</span></code></a> must be freed with <em class="manpage"><a class="manpage reference external" href="https://linux.die.net/man/3/free">free(3)</a></em>.</p>
 298 <p><a class="reference internal" href="#_CPPv413memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t" title="memcached_get"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_get()</span></code></a> will return NULL on
 299 error. You must look at the value of error to determine what the actual error
 300 was.</p>
 301 <p><a class="reference internal" href="#_CPPv423memcached_fetch_executeP12memcached_stP20memcached_execute_fnPv8uint32_t" title="memcached_fetch_execute"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_fetch_execute()</span></code></a> return <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t17MEMCACHED_SUCCESSE" title="MEMCACHED_SUCCESS"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_SUCCESS</span></code></a> if
 302 all keys were successful. <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t18MEMCACHED_NOTFOUNDE" title="MEMCACHED_NOTFOUND"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_NOTFOUND</span></code></a> will be return if no
 303 keys at all were found.</p>
 304 <p><a class="reference internal" href="#_CPPv422memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t" title="memcached_fetch_result"><code class="xref cpp cpp-func docutils literal notranslate"><span class="pre">memcached_fetch_result()</span></code></a> sets error
 305 to <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t13MEMCACHED_ENDE" title="MEMCACHED_END"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_END</span></code></a> upon successful conclusion.
 306 <a class="reference internal" href="memcached_return_t.html#_CPPv4N18memcached_return_t18MEMCACHED_NOTFOUNDE" title="MEMCACHED_NOTFOUND"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_NOTFOUND</span></code></a> will be return if no keys at all were found.</p>
 307 </div>
 308 <div class="section" id="see-also">
 309 <h2>SEE ALSO<a class="headerlink" href="#see-also" title="Permalink to this headline">¶</a></h2>
 310 </div>
 311 </div>
 312
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