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hustoj/web/cppreference-zh/chmhelp/c-string-multibyte-wctob.html
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<!DOCTYPE html>
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<title>wctob</title>
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<h1 id="firstHeading" class="firstHeading">wctob</h1>
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<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-multibyte.html">multibyte</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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<div><span class="mw-geshi c source-c"><span class="kw4">int</span> wctob<span class="br0">(</span> wint_t c <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td class="t-dcl-nopad"></td>
<td><span class="t-mark-rev t-since-c95">(C95 &#36215;)</span></td>
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<p>&#33509;&#23485;&#23383;&#31526; <code>c</code> &#30340;&#22810;&#23383;&#33410;&#23383;&#31526;&#31561;&#20215;&#22312;&#21021;&#22987;&#36801;&#31227;&#29366;&#24577;&#20026;&#21333;&#23383;&#33410;&#65292;&#21017;&#31364;&#21270;&#23427;&#12290;</p>
<p>&#36825;&#20856;&#22411;&#22320;&#23545;&#26469;&#33258; ASCII &#23383;&#31526;&#38598;&#30340;&#23383;&#31526;&#21487;&#34892;&#65292;&#22240;&#20026;&#22823;&#22810;&#25968;&#22810;&#23383;&#33410;&#32534;&#30721;&#65288;&#22914; UTF-8 &#65289;&#29992;&#21333;&#23383;&#33410;&#32534;&#30721;&#36825;&#20123;&#23383;&#31526;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
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<td>c</td>
<td>-</td>
<td>&#35201;&#31364;&#21270;&#30340;&#23485;&#23383;&#31526;</td>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p>&#33509; <code>c</code> &#19981;&#34920;&#31034;&#22312;&#21021;&#22987;&#36801;&#31227;&#29366;&#24577;&#38271;&#24230;&#20026; <span class="t-c"><span class="mw-geshi c source-c"><span class="nu0">1</span></span></span> &#30340;&#22810;&#23383;&#33410;&#23383;&#31526;&#65292;&#21017;&#36820;&#22238; <span class="t-lc"><a href="c-io.html">EOF</a></span> &#12290;</p>
<p>&#21542;&#21017;&#65292;&#36820;&#22238; <code>c</code> &#20316;&#20026; <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">unsigned</span> <span class="kw4">char</span></span></span> &#30340;&#21333;&#23383;&#33410;&#34920;&#31034;&#65292;&#24182;&#36716;&#25442;&#20026; <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">int</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">
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<pre class="de1"><span class="co2">#include &lt;locale.h&gt;</span>
<span class="co2">#include &lt;wchar.h&gt;</span>
<span class="co2">#include &lt;stdio.h&gt;</span>
<span class="co2">#include &lt;assert.h&gt;</span>
<span class="kw4">void</span> try_narrowing<span class="br0">(</span><span class="kw4">wchar_t</span> c<span class="br0">)</span>
<span class="br0">{</span>
<span class="kw4">int</span> cn <span class="sy1">=</span> wctob<span class="br0">(</span>c<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span>cn <span class="sy3">!</span><span class="sy1">=</span> <a href="c-io.html"><span class="kw888">EOF</span></a><span class="br0">)</span>
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot;%#x narrowed to %#x<span class="es1">\n</span>&quot;</span>, c, cn<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;%#x could not be narrowed<span class="es1">\n</span>&quot;</span>, c<span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</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">char</span><span class="sy2">*</span> utf_locale_present <span class="sy1">=</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;th_TH.utf8&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-error-assert.html"><span class="kw407">assert</span></a><span class="br0">(</span>utf_locale_present<span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-puts.html"><span class="kw835">puts</span></a><span class="br0">(</span><span class="st0">&quot;In Thai UTF-8 locale:&quot;</span><span class="br0">)</span><span class="sy4">;</span>
try_narrowing<span class="br0">(</span>L<span class="st0">&#39;a&#39;</span><span class="br0">)</span><span class="sy4">;</span>
try_narrowing<span class="br0">(</span>L<span class="st0">&#39;&#3675;&#39;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">char</span><span class="sy2">*</span> tis_locale_present <span class="sy1">=</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;th_TH.tis620&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-error-assert.html"><span class="kw407">assert</span></a><span class="br0">(</span>tis_locale_present<span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-puts.html"><span class="kw835">puts</span></a><span class="br0">(</span><span class="st0">&quot;In Thai TIS-620 locale:&quot;</span><span class="br0">)</span><span class="sy4">;</span>
try_narrowing<span class="br0">(</span>L<span class="st0">&#39;a&#39;</span><span class="br0">)</span><span class="sy4">;</span>
try_narrowing<span class="br0">(</span>L<span class="st0">&#39;&#3675;&#39;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
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<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">In Thai UTF-8 locale:
0x61 narrowed to 0x61
0xe5b could not be narrowed
In Thai TIS-620 locale:
0x61 narrowed to 0x61
0xe5b narrowed to 0xfb</pre></div>
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<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>
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<li>7.29.6.1.2 The wctob function (p: 441)</li>
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<div class="t-ref-std-c99">
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<li>C99 &#26631;&#20934;&#65288;ISO/IEC 9899:1999&#65289;&#65306;</li>
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<dd>
<ul>
<li>7.24.6.1.2 The wctob function (p: 387)</li>
</ul>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
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<div class="t-dsc-member-div">
<div><a href="c-string-multibyte-btowc.html"><span class="t-lines"><span>btowc</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c95">(C95)</span></span></span></div>
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<td>&#23558;&#21333;&#23383;&#33410;&#31364;&#23383;&#31526;&#21152;&#23485;&#25104;&#23485;&#23383;&#31526;&#65292;&#20504;&#33509;&#21487;&#33021;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
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