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200 <div class=
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201 <h1>Working with statistical information from a server
<a class=
"headerlink" href=
"#working-with-statistical-information-from-a-server" title=
"Permalink to this headline">¶
</a></h1>
202 <p>Get memcached statistics
</p>
203 <div class=
"section" id=
"synopsis">
204 <span id=
"index-0"></span><h2>SYNOPSIS
<a class=
"headerlink" href=
"#synopsis" title=
"Permalink to this headline">¶
</a></h2>
205 <p>#include
<libmemcached/memcached.h
></p>
206 <dl class=
"cpp type">
207 <dt id=
"_CPPv417memcached_stat_st">
208 <span id=
"_CPPv317memcached_stat_st"></span><span id=
"_CPPv217memcached_stat_st"></span><span id=
"memcached_stat_st"></span><em class=
"property">type
</em><code class=
"sig-name descname">memcached_stat_st
</code><a class=
"headerlink" href=
"#_CPPv417memcached_stat_st" title=
"Permalink to this definition">¶
</a><br /></dt>
211 <dl class=
"cpp type">
212 <dt id=
"_CPPv417memcached_stat_fn">
213 <span id=
"_CPPv317memcached_stat_fn"></span><span id=
"_CPPv217memcached_stat_fn"></span><span id=
"memcached_stat_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_stat_fn
</code>)
<span class=
"sig-paren">(
</span><em class=
"property">const
</em> memcached_instance_st *server,
<em class=
"property">const
</em> char *key, size_t key_length,
<em class=
"property">const
</em> char *value, size_t value_length, void *context
<span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv417memcached_stat_fn" title=
"Permalink to this definition">¶
</a><br /></dt>
216 <dl class=
"cpp function">
217 <dt id=
"_CPPv414memcached_statP12memcached_stPcP18memcached_return_t">
218 <span id=
"_CPPv314memcached_statP12memcached_stPcP18memcached_return_t"></span><span id=
"_CPPv214memcached_statP12memcached_stPcP18memcached_return_t"></span><span id=
"memcached_stat__memcached_stP.cP.memcached_return_tP"></span><a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st">memcached_stat_st
</a> *
<code class=
"sig-name descname">memcached_stat
</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>, char *
<em>args
</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=
"#_CPPv414memcached_statP12memcached_stPcP18memcached_return_t" title=
"Permalink to this definition">¶
</a><br /></dt>
221 <dl class=
"cpp function">
222 <dt id=
"_CPPv425memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t">
223 <span id=
"_CPPv325memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t"></span><span id=
"_CPPv225memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t"></span><span id=
"memcached_stat_servername__memcached_stat_stP.cP.cCP.in_port_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_stat_servername
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st">memcached_stat_st
</a> *
<em>stat
</em>, char *
<em>args
</em>,
<em class=
"property">const
</em> char *
<em>hostname
</em>, in_port_t
<em>port
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv425memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t" title=
"Permalink to this definition">¶
</a><br /></dt>
226 <dl class=
"cpp function">
227 <dt id=
"_CPPv424memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t">
228 <span id=
"_CPPv324memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t"></span><span id=
"_CPPv224memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t"></span><span id=
"memcached_stat_get_value__memcached_stP.memcached_stat_stP.cCP.memcached_return_tP"></span>char *
<code class=
"sig-name descname">memcached_stat_get_value
</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=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st">memcached_stat_st
</a> *
<em>stat
</em>,
<em class=
"property">const
</em> char *
<em>key
</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=
"#_CPPv424memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t" title=
"Permalink to this definition">¶
</a><br /></dt>
231 <dl class=
"cpp function">
232 <dt id=
"_CPPv423memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t">
233 <span id=
"_CPPv323memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t"></span><span id=
"_CPPv223memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t"></span><span id=
"memcached_stat_get_keys__memcached_stP.memcached_stat_stP.memcached_return_tP"></span>char **
<code class=
"sig-name descname">memcached_stat_get_keys
</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=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st">memcached_stat_st
</a> *
<em>stat
</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=
"#_CPPv423memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t" title=
"Permalink to this definition">¶
</a><br /></dt>
236 <dl class=
"cpp function">
237 <dt id=
"_CPPv422memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv">
238 <span id=
"_CPPv322memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv"></span><span id=
"_CPPv222memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv"></span><span id=
"memcached_stat_execute__memcached_stP.cCP.memcached_stat_fn.voidP"></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_stat_execute
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *
<em>memc
</em>,
<em class=
"property">const
</em> char *
<em>args
</em>,
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_fn" title=
"memcached_stat_fn">memcached_stat_fn
</a> <em>func
</em>, void *
<em>context
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv422memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv" title=
"Permalink to this definition">¶
</a><br /></dt>
241 <p>Compile and link with -lmemcached
</p>
243 <div class=
"section" id=
"description">
244 <h2>DESCRIPTION
<a class=
"headerlink" href=
"#description" title=
"Permalink to this headline">¶
</a></h2>
245 <p>libmemcached(
3) has the ability to query a memcached server (or collection
246 of servers) for their current state. Queries to find state return a
247 <a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_stat_st
</span></code></a> structure. You are responsible for freeing this structure. While it is possible to access the structure directly it is not advisable.
<a class=
"reference internal" href=
"#_CPPv424memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t" title=
"memcached_stat_get_value"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_get_value()
</span></code></a> has been provided to query the structure.
</p>
248 <p><a class=
"reference internal" href=
"#_CPPv422memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv" title=
"memcached_stat_execute"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_execute()
</span></code></a> uses the servers found in
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_stat_st
</span></code></a> and executes a
"stat
" command on each server. args is an optional argument that can be passed in to modify the behavior of
"stats
". You will need to supply a callback function that will be supplied each pair of values returned by
249 the memcached server.
</p>
250 <p><a class=
"reference internal" href=
"#_CPPv414memcached_statP12memcached_stPcP18memcached_return_t" title=
"memcached_stat"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat()
</span></code></a> fetches an array of
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_stat_st
</span></code></a> structures containing the state of all available memcached servers. The return value must be freed by the calling application. If called with the
<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> behavior set, a NULL value is returned and the error parameter is 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>
251 <p><a class=
"reference internal" href=
"#_CPPv425memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t" title=
"memcached_stat_servername"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_servername()
</span></code></a> can be used standalone without 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> to obtain the state of a particular server.
"args
" is used to define a particular state object (a list of these are not provided for by either
252 the
<a class=
"reference internal" href=
"#_CPPv423memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t" title=
"memcached_stat_get_keys"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_get_keys()
</span></code></a> call nor are they defined in the memcached protocol). You must specify the hostname and port of the server you want to
253 obtain information on.
</p>
254 <p><a class=
"reference internal" href=
"#_CPPv424memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t" title=
"memcached_stat_get_value"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_get_value()
</span></code></a> returns the value of a particular state key. You specify the key you wish to obtain. The key must be null terminated.
</p>
255 <p><a class=
"reference internal" href=
"#_CPPv423memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t" title=
"memcached_stat_get_keys"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_get_keys()
</span></code></a> returns a list of keys that the server has state objects on. You are responsible for freeing this list.
</p>
256 <p>A command line tool, memstat(
1), is provided so that you do not have to write
257 an application to do this.
</p>
259 <div class=
"section" id=
"return-value">
260 <h2>RETURN VALUE
<a class=
"headerlink" href=
"#return-value" title=
"Permalink to this headline">¶
</a></h2>
261 <p>Varies, see particular functions.
</p>
262 <p>Any method returning a
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_stat_st
</span></code></a> expects you to free the
263 memory allocated for it.
</p>
265 <div class=
"section" id=
"see-also">
266 <h2>SEE ALSO
<a class=
"headerlink" href=
"#see-also" title=
"Permalink to this headline">¶
</a></h2>
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"rst-footer-buttons" role=
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