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<h1 id="firstHeading" class="firstHeading">wcsncpy, wcsncpy_s</h1>
<div id="bodyContent">
<div id="contentSub"><span class="subpages">&lt; <a href="c.html">c</a>&lrm; | <a href="c-string.html">string</a>&lrm; | <a href="c-string-wide.html">wide</a></span></div>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;wchar.h&gt;</code></div>
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<td></td>
<td></td>
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<td rowspan="142">(1)</td>
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<div><span class="mw-geshi c source-c"><span class="kw4">wchar_t</span><span class="sy2">*</span> wcsncpy<span class="br0">(</span> <span class="kw4">wchar_t</span><span class="sy2">*</span> dest, <span class="kw4">const</span> <span class="kw4">wchar_t</span><span class="sy2">*</span> src, <a href="c-types-size_t.html"><span class="kw100">size_t</span></a> count <span class="br0">)</span><span class="sy4">;</span></span></div>
</td>
<td class="t-dcl-nopad"></td>
<td><span class="t-mark-rev t-since-c95">(C95 &#36215;)</span><br />
<span class="t-mark-rev t-until-c99">(C99 &#21069;)</span></td>
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<tr class="t-dcl t-since-c99">
<td>
<div><span class="mw-geshi c source-c"><span class="kw4">wchar_t</span> <span class="sy2">*</span>wcsncpy<span class="br0">(</span><span class="kw4">wchar_t</span> <span class="sy2">*</span><span class="kw4">restrict</span> dest, <span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span><span class="kw4">restrict</span> src, <a href="c-types-size_t.html"><span class="kw100">size_t</span></a> n<span class="br0">)</span><span class="sy4">;</span></span></div>
</td>
<td class="t-dcl-nopad"></td>
<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<tbody>
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<td>
<div><span class="mw-geshi c source-c">errno_t wcsncpy_s<span class="br0">(</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span><span class="kw4">restrict</span> dest, rsize_t destsz,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span><span class="kw4">restrict</span> src, rsize_t n<span class="br0">)</span><span class="sy4">;</span></span></div>
</td>
<td>(2)</td>
<td><span class="t-mark-rev t-since-c11">(C11 &#36215;)</span></td>
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<td></td>
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<div class="t-li1"><span class="t-li">1)</span> &#22797;&#21046; <code>src</code> &#25152;&#25351;&#21521;&#30340;&#23485;&#23383;&#31526;&#20018;&#30340;&#33267;&#22810; <code>count</code> &#20010;&#23383;&#31526;&#65288;&#21253;&#21547;&#32456;&#27490;&#31354;&#23485;&#23383;&#31526;&#65289;&#21040; <code>dest</code> &#25152;&#25351;&#21521;&#30340;&#23485;&#23383;&#31526;&#25968;&#32452;&#12290;</div>
<div class="t-li1"><span class="t-li"></span> &#33509;&#22312;&#23436;&#20840;&#22797;&#21046;&#25972;&#20010; <code>src</code> &#25968;&#32452;&#21069;&#25269;&#36798; <code>count</code> &#65292;&#21017;&#20135;&#29983;&#30340;&#23485;&#23383;&#31526;&#25968;&#32452;&#19981;&#26159;&#31354;&#32456;&#27490;&#30340;&#12290;</div>
<div class="t-li1"><span class="t-li"></span> &#33509;&#22312;&#22797;&#21046;&#26469;&#33258; <code>src</code> &#30340;&#32456;&#27490;&#31354;&#23485;&#23383;&#31526;&#21518;&#26410;&#25269;&#36798; <code>count</code> &#65292;&#21017;&#20889;&#20837;&#39069;&#22806;&#30340;&#31354;&#23485;&#23383;&#31526;&#21040; <code>dest</code> &#65292;&#30452;&#33267;&#20889;&#20837;&#24635;&#20849; <code>count</code> &#20010;&#23383;&#31526;&#12290;</div>
<div class="t-li1"><span class="t-li"></span> &#33509;&#23383;&#31526;&#20018;&#37325;&#21472;&#65292;&#21017;&#34892;&#20026;&#26410;&#23450;&#20041;&#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#21516; <span class="t-v">(1)</span> &#65292;&#38500;&#20102;&#20989;&#25968;&#19981;&#25345;&#32493;&#20889;&#20837;&#38646;&#21040;&#30446;&#26631;&#25968;&#32452;&#20197;&#22635;&#28385; <code>count</code> &#65292;&#23427;&#22312;&#20889;&#20837;&#32456;&#27490;&#31354;&#23485;&#23383;&#31526;&#21518;&#20572;&#27490;&#65288;&#33509;&#28304;&#20013;&#26080;&#31354;&#23485;&#23383;&#31526;&#65292;&#21017;&#23427;&#20110; <span class="t-c"><span class="mw-geshi c source-c">dest<span class="br0">[</span>count<span class="br0">]</span></span></span> &#20889;&#20837;&#19968;&#20010;&#28982;&#21518;&#20572;&#27490;&#65289; &#12290;&#24182;&#22312;&#36816;&#34892;&#26102;&#26816;&#27979;&#19979;&#21015;&#38169;&#35823;&#65292;&#24182;&#35843;&#29992;&#24403;&#21069;&#23433;&#35013;&#30340;<a href="c-error-set_constraint_handler_s.html">&#21046;&#32422;&#22788;&#29702;</a>&#20989;&#25968;&#65306;
<dl>
<dd>
<ul>
<li><code>src</code> &#25110; <code>dest</code> &#20026;&#31354;&#25351;&#38024;</li>
<li><code>destsz</code> &#25110; <code>count</code> &#20026;&#38646;&#25110;&#22823;&#20110; <span class="t-c"><span class="mw-geshi c source-c">RSIZE_MAX<span class="sy2">/</span><span class="kw4">sizeof</span><span class="br0">(</span><span class="kw4">wchar_t</span><span class="br0">)</span></span></span></li>
<li><code>count</code> &#22823;&#20110;&#25110;&#31561;&#20110; <code>destsz</code> &#65292;&#20294; <code>destsz</code> &#23567;&#20110;&#25110;&#31561;&#20110; <span class="t-c"><span class="mw-geshi c source-c">wcsnlen_s<span class="br0">(</span>src, count<span class="br0">)</span></span></span> &#65292;&#25442;&#35328;&#20043;&#65292;&#20250;&#20986;&#29616;&#25130;&#26029;</li>
<li>&#28304;&#19982;&#30446;&#26631;&#23383;&#31526;&#20018;&#38388;&#20250;&#20986;&#29616;&#37325;&#21472;</li>
</ul>
</dd>
<dd></dd>
<dd>&#21516;&#25152;&#26377;&#36793;&#30028;&#26816;&#26597;&#20989;&#25968;&#65292; <code>wcsncpy_s</code> &#20165;&#33509;&#23454;&#29616;&#23450;&#20041;&#20102; <span class="t-c"><span class="mw-geshi c source-c">__STDC_LIB_EXT1__</span></span> &#65292;&#19988;&#29992;&#25143;&#22312;&#21253;&#21547; <code>wchar.h</code> &#21069;&#23450;&#20041; <span class="t-c"><span class="mw-geshi c source-c">__STDC_WANT_LIB_EXT1__</span></span> &#20026;&#25972;&#25968;&#24120;&#37327; <span class="t-c"><span class="mw-geshi c source-c"><span class="nu0">1</span></span></span> &#25165;&#20445;&#35777;&#21487;&#29992;&#12290;</dd>
</dl>
</div>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
<table class="t-par-begin">
<tr class="t-par">
<td>dest</td>
<td>-</td>
<td>&#25351;&#21521;&#35201;&#22797;&#21046;&#21040;&#30340;&#23485;&#23383;&#31526;&#25968;&#32452;&#30340;&#25351;&#38024;</td>
</tr>
<tr class="t-par">
<td>src</td>
<td>-</td>
<td>&#25351;&#21521;&#22797;&#21046;&#26469;&#28304;&#30340;&#23485;&#23383;&#31526;&#20018;&#30340;&#25351;&#38024;</td>
</tr>
<tr class="t-par">
<td>count</td>
<td>-</td>
<td>&#35201;&#22797;&#21046;&#30340;&#26368;&#22823;&#23485;&#23383;&#31526;&#25968;</td>
</tr>
<tr class="t-par">
<td>destsz</td>
<td>-</td>
<td>&#30446;&#26631;&#32531;&#20914;&#21306;&#30340;&#22823;&#23567;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<div class="t-li1"><span class="t-li">1)</span> &#36820;&#22238; <code>dest</code> &#30340;&#21103;&#26412;&#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#25104;&#21151;&#26102;&#36820;&#22238;&#38646;&#65292;&#38169;&#35823;&#26102;&#36820;&#22238;&#38750;&#38646;&#12290;&#32780;&#19988;&#65292;&#22312;&#38169;&#35823;&#26102;&#20889;&#20837; <span class="t-c"><span class="mw-geshi c source-c">L<span class="st0">&#39;<span class="es5">\0</span>&#39;</span></span></span> &#21040; <span class="t-c"><span class="mw-geshi c source-c">dest<span class="br0">[</span><span class="nu0">0</span><span class="br0">]</span></span></span> &#65288;&#38500;&#38750; <code>dest</code> &#20026;&#31354;&#25351;&#38024;&#65292;&#25110; <code>destsz</code> &#20026;&#38646;&#25110;&#22823;&#20110; <span class="t-c"><span class="mw-geshi c source-c">RSIZE_MAX<span class="sy2">/</span><span class="kw4">sizeof</span><span class="br0">(</span><span class="kw4">wchar_t</span><span class="br0">)</span></span></span> &#65289;&#65292;&#32780;&#19988;&#21487;&#33021;&#20197;&#26410;&#25351;&#23450;&#20540;&#30772;&#22351;&#30446;&#26631;&#25968;&#32452;&#30340;&#21097;&#20313;&#37096;&#20998;&#12290;</div>
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">&#27880;&#24847;</span></h3>
<p>&#20856;&#22411;&#29992;&#27861;&#20013;&#65292; <code>count</code> &#26159;&#30446;&#26631;&#25968;&#32452;&#20013;&#30340;&#20803;&#32032;&#25968;&#12290;</p>
<p>&#23613;&#31649;&#36866;&#21512;&#30446;&#26631;&#32531;&#20914;&#21306;&#30340;&#25130;&#26029;&#26159;&#23433;&#20840;&#39118;&#38505;&#65292;&#20174;&#32780;&#26159; <code>wcsncpy_s</code> &#30340;&#36816;&#34892;&#26102;&#21046;&#32422;&#36829;&#35268;&#65292;&#36824;&#26159;&#21487;&#36890;&#36807;&#25351;&#23450; <code>count</code> &#31561;&#20110;&#30446;&#26631;&#25968;&#32452;&#22823;&#23567;&#20943;&#19968;&#33719;&#21462;&#25130;&#26029;&#34892;&#20026;&#65306;&#23427;&#23558;&#22797;&#21046;&#39318; <code>count</code> &#20010;&#23485;&#23383;&#31526;&#65292;&#24182;&#29031;&#24120;&#21518;&#38468;&#31354;&#23485;&#32456;&#27490;&#31526;&#65306; <span class="t-c"><span class="mw-geshi c source-c">wcsncpy_s<span class="br0">(</span>dst, <span class="kw4">sizeof</span> dst <span class="sy2">/</span> <span class="kw4">sizeof</span> <span class="sy2">*</span>dst, src, <span class="br0">(</span><span class="kw4">sizeof</span> dst <span class="sy2">/</span> <span class="kw4">sizeof</span> <span class="sy2">*</span>dst<span class="br0">)</span><span class="sy2">-</span><span class="nu0">1</span><span class="br0">)</span><span class="sy4">;</span></span></span> &#12290;</p>
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</span></h3>
<div class="t-example">
<div class="t-example-live-link"></div>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="c source-c">
<pre class="de1"><span class="co2">#include &lt;stdio.h&gt;</span>
<span class="co2">#include &lt;wchar.h&gt;</span>
<span class="co2">#include &lt;locale.h&gt;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="kw4">void</span><span class="br0">)</span>
<span class="br0">{</span>
<span class="kw4">wchar_t</span> src<span class="br0">[</span><span class="br0">]</span> <span class="sy1">=</span> L<span class="st0">&quot;&#12431;&#12432;&quot;</span><span class="sy4">;</span>
<span class="kw4">wchar_t</span> dest<span class="br0">[</span><span class="nu0">6</span><span class="br0">]</span> <span class="sy1">=</span> <span class="br0">{</span>L<span class="st0">&#39;&#12354;&#39;</span>, L<span class="st0">&#39;&#12356;&#39;</span>, L<span class="st0">&#39;&#12358;&#39;</span>, L<span class="st0">&#39;&#12360;&#39;</span>, L<span class="st0">&#39;&#12362;&#39;</span><span class="br0">}</span><span class="sy4">;</span>
wcsncpy<span class="br0">(</span>dest, src, <span class="nu0">4</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// &#36825;&#23558;&#22797;&#21046; &#12431;&#12432; &#24182;&#37325;&#22797; L&#39;\0&#39; &#20108;&#27425;</span>
<a href="c-io-puts.html"><span class="kw835">puts</span></a><span class="br0">(</span><span class="st0">&quot;The contents of dest are: &quot;</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-locale-setlocale.html"><span class="kw900">setlocale</span></a><span class="br0">(</span><a href="c-locale-LC_categories.html"><span class="kw903">LC_ALL</span></a>, <span class="st0">&quot;en_US.utf8&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">for</span><span class="br0">(</span><span class="kw4">wchar_t</span><span class="sy2">*</span> p <span class="sy1">=</span> dest<span class="sy4">;</span> p<span class="sy2">-</span>dest <span class="sy1">&lt;</span> <span class="kw4">sizeof</span> dest <span class="sy2">/</span> <span class="kw4">sizeof</span> <span class="sy2">*</span>dest<span class="sy4">;</span> <span class="sy2">++</span>p<span class="br0">)</span> <span class="br0">{</span>
<span class="kw1">if</span><span class="br0">(</span><span class="sy2">*</span>p<span class="br0">)</span>
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot;%lc &quot;</span>, <span class="sy2">*</span>p<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">else</span>
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot;<span class="es1">\\</span>0 &quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="br0">}</span></pre></div>
</div>
<p>&#21487;&#33021;&#30340;&#36755;&#20986;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="text source-text">
<pre class="de1">The contents of dest are:
&#12431; &#12432; \0 \0 &#12362; \0</pre></div>
</div>
</div>
<h3><span class="mw-headline" id=".E5.BC.95.E7.94.A8">&#24341;&#29992;</span></h3>
<div class="t-ref-std-11">
<ul>
<li>C11 &#26631;&#20934;&#65288;ISO/IEC 9899:2011&#65289;&#65306;</li>
</ul>
<dl>
<dd>
<ul>
<li>7.29.4.2.2 The wcsncpy function (p: 431)</li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li>K.3.9.2.1.2 The wcsncpy_s function (p: 640-641)</li>
</ul>
</dd>
</dl>
<div class="t-ref-std-c99">
<ul>
<li>C99 &#26631;&#20934;&#65288;ISO/IEC 9899:1999&#65289;&#65306;</li>
</ul>
<dl>
<dd>
<ul>
<li>7.24.4.2.2 The wcsncpy function (p: 377)</li>
</ul>
</dd>
</dl>
</div>
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="c-string-wide-wcscpy.html"><span class="t-lines"><span>wcscpy</span><span>wcscpy_s</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c95">(C95)</span></span><span><span class="t-mark-rev t-since-c11">(C11)</span></span></span></div>
</div>
</td>
<td>&#23558;&#19968;&#20010;&#23485;&#23383;&#31526;&#20018;&#22797;&#21046;&#32473;&#21478;&#19968;&#20010;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="c-string-wide-wmemcpy.html"><span class="t-lines"><span>wmemcpy</span><span>wmemcpy_s</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c95">(C95)</span></span><span><span class="t-mark-rev t-since-c11">(C11)</span></span></span></div>
</div>
</td>
<td>&#22312;&#20004;&#20010;&#19981;&#37325;&#21472;&#30340;&#25968;&#32452;&#38388;&#22797;&#21046;&#19968;&#23450;&#25968;&#37327;&#30340;&#23485;&#23383;&#31526;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="c-string-byte-strncpy.html"><span class="t-lines"><span>strncpy</span><span>strncpy_s</span></span></a></div>
<div><span class="t-lines"><span></span><span><span class="t-mark-rev t-since-c11">(C11)</span></span></span></div>
</div>
</td>
<td>&#20174;&#19968;&#20010;&#23383;&#31526;&#20018;&#22797;&#21046;&#19968;&#23450;&#25968;&#37327;&#30340;&#23383;&#31526;&#21040;&#21478;&#19968;&#20010;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
</table>
</div>
</div>
<div class="visualClear"></div>
</div>
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