229 lines
17 KiB
HTML
229 lines
17 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
|
|
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<title>wcstok, wcstok_s</title>
|
|
<link rel="stylesheet" href="ext.css" />
|
|
<link rel="stylesheet" href="site_modules.css" />
|
|
</head>
|
|
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-c_string_wide_wcstok skin-cppreference2 action-view cpp-navbar">
|
|
<div id="cpp-content-base">
|
|
<div id="content"><a id="top"></a>
|
|
<h1 id="firstHeading" class="firstHeading">wcstok, wcstok_s</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="c.html">c</a>‎ | <a href="c-string.html">string</a>‎ | <a href="c-string-wide.html">wide</a></span></div>
|
|
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dsc-header">
|
|
<td>
|
|
<div>定义于头文件 <code><wchar.h></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
<tbody class="t-dcl-rev t-dcl-rev-num">
|
|
<tr class="t-dcl-rev-aux">
|
|
<td></td>
|
|
<td rowspan="142">(1)</td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-c95 t-until-c99">
|
|
<td>
|
|
<div><span class="mw-geshi c source-c"><span class="kw4">wchar_t</span><span class="sy2">*</span> wcstok<span class="br0">(</span> <span class="kw4">wchar_t</span><span class="sy2">*</span> str, <span class="kw4">const</span> <span class="kw4">wchar_t</span><span class="sy2">*</span> delim, <span class="kw4">wchar_t</span> <span class="sy2">**</span>ptr <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 起)</span><br />
|
|
<span class="t-mark-rev t-until-c99">(C99 前)</span></td>
|
|
</tr>
|
|
<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>wcstok<span class="br0">(</span><span class="kw4">wchar_t</span> <span class="sy2">*</span> <span class="kw4">restrict</span> str, <span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span> <span class="kw4">restrict</span> delim,<br />
|
|
<span class="kw4">wchar_t</span> <span class="sy2">**</span><span class="kw4">restrict</span> ptr<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 起)</span></td>
|
|
</tr>
|
|
</tbody>
|
|
<tbody>
|
|
<tr class="t-dcl t-since-c11">
|
|
<td>
|
|
<div><span class="mw-geshi c source-c"><span class="kw4">wchar_t</span> <span class="sy2">*</span>wcstok_s<span class="br0">(</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span><span class="kw4">restrict</span> str, rsize_t <span class="sy2">*</span><span class="kw4">restrict</span> strmax,<br />
|
|
<span class="kw4">const</span> <span class="kw4">wchar_t</span> <span class="sy2">*</span><span class="kw4">restrict</span> delim, <span class="kw4">wchar_t</span> <span class="sy2">**</span><span class="kw4">restrict</span> ptr<span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(2)</td>
|
|
<td><span class="t-mark-rev t-since-c11">(C11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<div class="t-li1"><span class="t-li">1)</span> 寻找 <code>str</code> 所指向的空终止宽字符串中的下个记号。以 <code>delim</code> 所指向的空终止宽字符串鉴别分隔符。</div>
|
|
<div class="t-li1"><span class="t-li"></span> 此函数被设计为调用多次以从同一字符串获得相继的记号。</div>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>若 <span class="t-c"><span class="mw-geshi c source-c">str <span class="sy3">!</span><span class="sy1">=</span> <a href="c-types-NULL.html"><span class="kw103">NULL</span></a></span></span> ，则调用被当做 <code>wcstok</code> 首次对此具体宽字符的调用。函数搜索首个<i>不</i>含于 <code>delim</code> 的字符。</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>若找不到这种宽字符，则 <code>str</code> 中完全无记号，而函数返回空指针。</li>
|
|
<li>若找到这种宽字符，则它是<i>记号起始</i>。然后函数从该点搜索首个<i>含于</i> <code>delim</code> 的宽字符。</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>若找不到这种宽字符，则 <code>str</code> 只有一个记号，而对 <code>wcstok</code> 的将来调用将返回空指针</li>
|
|
<li>若找到这种宽字符，则以空宽字符 <span class="t-c"><span class="mw-geshi c source-c">L<span class="st0">'<span class="es5">\0</span>'</span></span></span> <i>替换</i>它，并存储分析状态（典型地为指向后一宽字符的指针）于用户提供位置 <span class="t-c"><span class="mw-geshi c source-c"><span class="sy2">*</span>ptr</span></span> 。</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<ul>
|
|
<li>然后函数返回指向记号起始的指针</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<ul>
|
|
<li>若 <span class="t-c"><span class="mw-geshi c source-c">str <span class="sy1">==</span> <a href="c-types-NULL.html"><span class="kw103">NULL</span></a></span></span> ，则调用被当作对 <code>wcstok</code> 的后继调用：函数从带同一 <span class="t-c"><span class="mw-geshi c source-c"><span class="sy2">*</span>ptr</span></span> 的先前调用所留下的位置开始持续。行为与如同将指向后随上次检测的记号的宽字符的指针作为 <span class="t-c"><span class="mw-geshi c source-c">str</span></span> 传递相同。</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<div class="t-li1"><span class="t-li">2)</span> 同 <span class="t-v">(1)</span> 除了在每步时，写入 <code>str</code> 中留待查看的字符数到 <span class="t-c"><span class="mw-geshi c source-c"><span class="sy2">*</span>strmax</span></span> 。 重复的调用（以空 <code>str</code> ）必须传递先前的调用用以存储值的 <code>strmax</code> 和 <code>ptr</code> 。并且在运行时检测下列错误，并调用当前安装的<a href="c-error-set_constraint_handler_s.html">制约处理</a>函数：
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li><code>strmax</code> 、 <code>delim</code> 或 <code>ptr</code> 为空指针</li>
|
|
<li>在非首次调用（以空 <code>str</code> ）时， <code>*ptr</code> 为空指针</li>
|
|
<li>首次调用时， <span class="t-c"><span class="mw-geshi c source-c"><span class="sy2">*</span>strmax</span></span> 为零或大于 <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>对记号的搜索抵达源字符串结尾（以 <span class="t-c"><span class="mw-geshi c source-c"><span class="sy2">*</span>strmax</span></span> 的初值测量），而未遇到空终止符</li>
|
|
</ul>
|
|
</dd>
|
|
<dd></dd>
|
|
<dd>同所有边界检查函数， <code>wcstok_s</code> 仅若实现定义了 <span class="t-c"><span class="mw-geshi c source-c">__STDC_LIB_EXT1__</span></span> ，且用户在包含 <code>wchar.h</code> 前定义 <span class="t-c"><span class="mw-geshi c source-c">__STDC_WANT_LIB_EXT1__</span></span> 为整数常量 <span class="t-c"><span class="mw-geshi c source-c"><span class="nu0">1</span></span></span> 才保证可用。</dd>
|
|
</dl>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
|
|
<table class="t-par-begin">
|
|
<tr class="t-par">
|
|
<td>str</td>
|
|
<td>-</td>
|
|
<td>指向要记号化的空终止宽字符串的指针</td>
|
|
</tr>
|
|
<tr class="t-par">
|
|
<td>delim</td>
|
|
<td>-</td>
|
|
<td>指向标识分隔符的空终止宽字符串的指针</td>
|
|
</tr>
|
|
<tr class="t-par">
|
|
<td>ptr</td>
|
|
<td>-</td>
|
|
<td>指向 <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">wchar_t</span><span class="sy2">*</span></span></span> 类型对象的指针， <code>wcstok</code> 和 <code>wcstok_s</code> 以之存储分析器的内部状态</td>
|
|
</tr>
|
|
<tr class="t-par">
|
|
<td>strmax</td>
|
|
<td>-</td>
|
|
<td>指向最初保有 <code>str</code> 大小的对象： wcstok_s 存储留待检验的字符数</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p>返回指向下个记号起始的指针，或若无更多记号则为空指针。</p>
|
|
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
|
|
<p>此函数是破坏性的：它写入 <span class="t-c"><span class="mw-geshi c source-c">L<span class="st0">'<span class="es5">\0</span>'</span></span></span> 字符于字符串 <code>str</code> 的元素。特别是，宽字符串字面量不能用作 <code>wcstok</code> 的首参数。</p>
|
|
<p>不同于 <span class="t-lc"><a href="c-string-byte-strtok.html">strtok</a></span> ， <code>wcstok</code> 不更新静态存储：它存储分析状态于用户提供的位置。</p>
|
|
<p>不同于大多数其他记号化器， <code>wcstok</code> 中的分隔符能对于后继记号不同，而且甚至能依赖于先前记号的内容。</p>
|
|
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</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 <wchar.h></span>
|
|
<span class="co2">#include <stdio.h></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> input<span class="br0">[</span><span class="br0">]</span> <span class="sy1">=</span> L<span class="st0">"A bird came down the walk"</span><span class="sy4">;</span>
|
|
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"Parsing the input string '%ls'<span class="es1">\n</span>"</span>, input<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw4">wchar_t</span> <span class="sy2">*</span>buffer<span class="sy4">;</span>
|
|
<span class="kw4">wchar_t</span> <span class="sy2">*</span>token <span class="sy1">=</span> wcstok<span class="br0">(</span>input, L<span class="st0">" "</span>, <span class="sy3">&</span>buffer<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">while</span><span class="br0">(</span>token<span class="br0">)</span> <span class="br0">{</span>
|
|
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"%ls<span class="es1">\n</span>"</span>, token<span class="br0">)</span><span class="sy4">;</span>
|
|
token <span class="sy1">=</span> wcstok<span class="br0">(</span><a href="c-types-NULL.html"><span class="kw103">NULL</span></a>, L<span class="st0">" "</span>, <span class="sy3">&</span>buffer<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span>
|
|
|
|
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"Contents of the input string now: '"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">for</span><span class="br0">(</span><a href="c-types-size_t.html"><span class="kw100">size_t</span></a> n <span class="sy1">=</span> <span class="nu0">0</span><span class="sy4">;</span> n <span class="sy1"><</span> <span class="kw4">sizeof</span> input <span class="sy2">/</span> <span class="kw4">sizeof</span> <span class="sy2">*</span>input<span class="sy4">;</span> <span class="sy2">++</span>n<span class="br0">)</span>
|
|
input<span class="br0">[</span>n<span class="br0">]</span> <span class="sy4">?</span> <a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"%lc"</span>, input<span class="br0">[</span>n<span class="br0">]</span><span class="br0">)</span> <span class="sy4">:</span> <a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">"<span class="es1">\\</span>0"</span><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">"'"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
<p>输出：</p>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="text source-text">
|
|
<pre class="de1">Parsing the input string 'A bird came down the walk'
|
|
A
|
|
bird
|
|
came
|
|
down
|
|
the
|
|
walk
|
|
Contents of the input string now: 'A\0bird\0came\0down\0the\0walk\0'</pre></div>
|
|
</div>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.BC.95.E7.94.A8">引用</span></h3>
|
|
<div class="t-ref-std-11">
|
|
<ul>
|
|
<li>C11 标准（ISO/IEC 9899:2011）：</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.29.4.5.7 The wcstok function (p: 437-438)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>K.3.9.2.3.1 The wcstok_s function (p: 645-646)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<div class="t-ref-std-c99">
|
|
<ul>
|
|
<li>C99 标准（ISO/IEC 9899:1999）：</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.24.4.5.7 The wcstok function (p: 383-384)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-string-byte-strtok.html"><span class="t-lines"><span>strtok</span><span>strtok_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>查找字节字符串中的下一个记号<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|