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 194   <div class="section" id="retrieving-data-from-the-server">
 195 <h1>Retrieving data from the server<a class="headerlink" href="#retrieving-data-from-the-server" title="Permalink to this headline">¶</a></h1>
 196 <div class="section" id="synopsis">
 197 <h2>SYNOPSIS<a class="headerlink" href="#synopsis" title="Permalink to this headline">¶</a></h2>
 198 <dl class="simple">
 199 <dt>#include &lt;libmemcached/memcached.h&gt;</dt><dd><p>Compile and link with -lmemcached</p>
 200 </dd>
 201 </dl>
 202 <dl class="cpp function">
 203 <dt id="_CPPv422memcached_fetch_resultP12memcached_stP19memcached_result_stP18memcached_return_t">
 204 <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>
 205 <dd></dd></dl>
 206
 207 <dl class="cpp function">
 208 <dt id="_CPPv413memcached_getP12memcached_stPKc6size_tP6size_tP8uint32_tP18memcached_return_t">
 209 <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>
 210 <dd></dd></dl>
 211
 212 <dl class="cpp function">
 213 <dt id="_CPPv414memcached_mgetP12memcached_stPPCKcPK6size_t6size_t">
 214 <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>
 215 <dd></dd></dl>
 216
 217 <dl class="cpp function">
 218 <dt id="_CPPv420memcached_get_by_keyP12memcached_stPKc6size_tPKc6size_tP6size_tP8uint32_tP18memcached_return_t">
 219 <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>
 220 <dd></dd></dl>
 221
 222 <dl class="cpp function">
 223 <dt id="_CPPv421memcached_mget_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_t">
 224 <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>
 225 <dd></dd></dl>
 226
 227 <dl class="cpp function">
 228 <dt id="_CPPv423memcached_fetch_executeP12memcached_stP20memcached_execute_fnPv8uint32_t">
 229 <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>
 230 <dd></dd></dl>
 231
 232 <dl class="cpp function">
 233 <dt id="_CPPv422memcached_mget_executeP12memcached_stPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t">
 234 <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>
 235 <dd></dd></dl>
 236
 237 <dl class="cpp function">
 238 <dt id="_CPPv429memcached_mget_execute_by_keyP12memcached_stPKc6size_tPPCKcPK6size_t6size_tP20memcached_execute_fnPv8uint32_t">
 239 <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>
 240 <dd></dd></dl>
 241
 242 <dl class="cpp type">
 243 <dt id="_CPPv420memcached_execute_fn">
 244 <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>
 245 <dd></dd></dl>
 246
 247 </div>
 248 <div class="section" id="description">
 249 <h2>DESCRIPTION<a class="headerlink" href="#description" title="Permalink to this headline">¶</a></h2>
 250 <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.
 251 You must pass in a key and its length to fetch the object. You must supply
 252 three pointer variables which will give you the state of the returned
 253 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
 254 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
 255 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
 256 object will be returned upon success and NULL will be returned on failure. Any
 257 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
 258 application.</p>
 259 <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
 260 multiple key operations it is always faster to use this function.
 261 This function always works asynchronously.</p>
 262 <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
 263 will need to 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
 264 this function until it returns a NULL (i.e. no more values). If you need to quit
 265 in the middle of a <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
 266 <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>
 267 <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
 268 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.
 269 You must pass in a key and its length to fetch the object. You must supply
 270 three pointer variables which will give you the state of the returned object.
 271 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,
 272 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 object, and a
 273 <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 object will be
 274 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
 275 returned by the *error value when all objects that have been found have been
 276 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>
 277 <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>
 278 structure from a memcached server. The result object is forward compatible
 279 with changes to the server. For more information please refer to the
 280 <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
 281 result structure for you if you do not pass one to the function.</p>
 282 <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.
 283 Instead of returning the results to you for processing, it passes each of the
 284 result sets to the list of functions you provide. It passes to the function
 285 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
 286 function (it can not be used directly). It also passes a result set which does
 287 not need to be freed. Finally it passes a &quot;context&quot;. This is just a pointer to
 288 a memory reference you supply the calling function. Currently only one value
 289 is being passed to each function call. In the future there will be an option
 290 to allow this to be an array.</p>
 291 <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>
 292 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
 293 callbacks with result sets while sending out the queries. If you try to
 294 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
 295 encounter a deadlock in the OS kernel (it will fail to write data to the
 296 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>
 297 solves this problem by processing some of the results before continuing
 298 sending out requests. Please note that this function is only available in
 299 the binary protocol.</p>
 300 <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
 301 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>.
 302 The difference is that they take a master key that is used for determining
 303 which server an object was stored if key partitioning was used for storage.</p>
 304 <p>All of the above functions are not tested when the
 305 <a class="reference internal" href="memcached_behavior.html#_CPPv4N20memcached_behavior_t26MEMCACHED_BEHAVIOR_USE_UDPE" title="MEMCACHED_BEHAVIOR_USE_UDP"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_BEHAVIOR_USE_UDP</span></code></a> has been set. Executing any of these
 306 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
 307 returned, or for those functions which do not return a
 308 <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
 309 <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>
 310 </div>
 311 <div class="section" id="return-value">
 312 <h2>RETURN VALUE<a class="headerlink" href="#return-value" title="Permalink to this headline">¶</a></h2>
 313 <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>
 314 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>
 315 <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 error.
 316 You must look at the value of error to determine what the actual error was.</p>
 317 <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
 318 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 returned if no
 319 keys at all were found.</p>
 320 <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
 321 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.
 322 <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 returned if no keys at all were found.</p>
 323 </div>
 324 <div class="section" id="see-also">
 325 <h2>SEE ALSO<a class="headerlink" href="#see-also" title="Permalink to this headline">¶</a></h2>
 326 <ul class="simple">
 327 <li><p><em class="manpage"><a class="manpage reference external" href="https://linux.die.net/man/1/memcached">memcached(1)</a></em></p></li>
 328 <li><p><a class="reference internal" href="../libmemcached.html"><span class="doc">C/C++ Client Library for memcached</span></a></p></li>
 329 <li><p><a class="reference internal" href="memcached_strerror.html"><span class="doc">Converting Error Codes to Messages</span></a></p></li>
 330 </ul>
 331 </div>
 332 </div>
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