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185 <div class=
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186 <h1>Determine if a keys exists
<a class=
"headerlink" href=
"#determine-if-a-keys-exists" title=
"Permalink to this headline">¶
</a></h1>
187 <div class=
"section" id=
"synopsis">
188 <h2>SYNOPSIS
<a class=
"headerlink" href=
"#synopsis" title=
"Permalink to this headline">¶
</a></h2>
189 <dl class=
"docutils">
190 <dt>#include
<libmemcached/memcached.h
></dt>
191 <dd>Compile and link with -lmemcached
</dd>
193 <dl class=
"function">
194 <dt id=
"_CPPv415memcached_existP12memcached_stPcP6size_t">
195 <span id=
"_CPPv315memcached_existP12memcached_stPcP6size_t"></span><span id=
"_CPPv215memcached_existP12memcached_stPcP6size_t"></span><span id=
"memcached_exist__memcached_stP.cP.sP"></span><a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> <code class=
"descname">memcached_exist
</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>key
</em>, size_t *
<em>key_length
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv415memcached_existP12memcached_stPcP6size_t" title=
"Permalink to this definition">¶
</a><br /></dt>
198 <dl class=
"function">
199 <dt id=
"_CPPv422memcached_exist_by_keyP12memcached_stPcP6size_tPcP6size_t">
200 <span id=
"_CPPv322memcached_exist_by_keyP12memcached_stPcP6size_tPcP6size_t"></span><span id=
"_CPPv222memcached_exist_by_keyP12memcached_stPcP6size_tPcP6size_t"></span><span id=
"memcached_exist_by_key__memcached_stP.cP.sP.cP.sP"></span><a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> <code class=
"descname">memcached_exist_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>, char *
<em>group_key
</em>, size_t *
<em>group_key_length
</em>, char *
<em>key
</em>, size_t *
<em>key_length
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv422memcached_exist_by_keyP12memcached_stPcP6size_tPcP6size_t" title=
"Permalink to this definition">¶
</a><br /></dt>
201 <dd><table class=
"docutils field-list" frame=
"void" rules=
"none">
202 <col class=
"field-name" />
203 <col class=
"field-body" />
205 <tr class=
"field-odd field"><th class=
"field-name">Parameters:
</th><td class=
"field-body"><ul class=
"first simple">
206 <li><strong>ptr
</strong> -- pointer to an initialized
<a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">memcached_st
</span></code></a> struct
</li>
207 <li><strong>group_key
</strong> -- the key namespace
</li>
208 <li><strong>group_key_length
</strong> -- length of the
<a class=
"reference internal" href=
"#_CPPv422memcached_exist_by_keyP12memcached_stPcP6size_tPcP6size_t" title=
"memcached_exist_by_key::group_key"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">group_key
</span></code></a> without any terminating zero
</li>
209 <li><strong>key
</strong> -- the key to check
</li>
210 <li><strong>key_length
</strong> -- length of the
<a class=
"reference internal" href=
"#_CPPv422memcached_exist_by_keyP12memcached_stPcP6size_tPcP6size_t" title=
"memcached_exist_by_key::key"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">key
</span></code></a> without any terminating zero
</li>
214 <tr class=
"field-even field"><th class=
"field-name">Returns:
</th><td class=
"field-body"><p class=
"first last"><a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">memcached_return_t
</span></code></a> indicating success
</p>
221 <div class=
"versionadded">
222 <p><span class=
"versionmodified">New in version
0.53.
</span></p>
225 <div class=
"section" id=
"description">
226 <h2>DESCRIPTION
<a class=
"headerlink" href=
"#description" title=
"Permalink to this headline">¶
</a></h2>
227 <p><a class=
"reference internal" href=
"#_CPPv415memcached_existP12memcached_stPcP6size_t" title=
"memcached_exist"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_exist()
</span></code></a> can be used to check if a key exists.
</p>
229 <div class=
"section" id=
"return-value">
230 <h2>RETURN VALUE
<a class=
"headerlink" href=
"#return-value" title=
"Permalink to this headline">¶
</a></h2>
231 <dl class=
"docutils">
232 <dt><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></dt>
233 <dd>The key exists.
</dd>
234 <dt><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></dt>
235 <dd>The key was not found.
</dd>
238 <div class=
"section" id=
"see-also">
239 <h2>SEE ALSO
<a class=
"headerlink" href=
"#see-also" title=
"Permalink to this headline">¶
</a></h2>
241 <li><em class=
"manpage"><a class=
"manpage reference external" href=
"https://linux.die.net/man/1/memcached">memcached(
1)
</a></em></li>
242 <li><a class=
"reference internal" href=
"../libmemcached.html"><span class=
"doc">C/C++ Client Library for memcached
</span></a></li>
243 <li><a class=
"reference internal" href=
"memcached_strerror.html"><span class=
"doc">Converting Error Codes to Messages
</span></a></li>
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