110 lines
8.0 KiB
HTML
110 lines
8.0 KiB
HTML
<!DOCTYPE html>
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<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
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<head><meta http-equiv="x-ua-compatible" content="ie=edge">
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<title>std::strerror</title>
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<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_string_byte_strerror skin-cppreference2 action-view cpp-navbar">
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<div id="cpp-content-base">
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<div id="content"><a id="top"></a>
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>strerror</h1>
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<div id="bodyContent">
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-string.html">string</a>‎ | <a href="cpp-string-byte.html">byte</a></span></div>
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<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
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<table class="t-dcl-begin">
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<td>
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<div>定义于头文件 <code><a href="cpp-header-cstring.html"><cstring></a></code></div>
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<td></td>
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<td></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">char</span><span class="sy2">*</span> strerror<span class="br0">(</span> <span class="kw4">int</span> errnum <span class="br0">)</span><span class="sy4">;</span></span></div>
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<p>返回指向系统错误码 <code>errnum</code> 的文本表示的指针，它等同于 <span class="t-lc"><a href="cpp-io-c-perror.html">std::perror()</a></span> 会打印的描述。</p>
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<p>通常从 <code>errno</code> 对象获得 <code>errnum</code> ，不过函数接受任何 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">int</span></span></span> 类型值。字符串的内容是本地环境限定的。</p>
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<p>程序必须不修改返回的字符串，但对 <code>strerror</code> 函数的后继调用可能重写该字符串。不要求 <code>strerror</code> 为线程安全。实现可以返回指向静态只读字符串字面量的不同指针，或反复返回指向静态缓冲区的同一指针而 strerror 于该缓冲区中放置字符串。</p>
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<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
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<table class="t-par-begin">
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<tr class="t-par">
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<td>errnum</td>
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<td>-</td>
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<td>指代错误码的整数值</td>
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</tr>
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</table>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
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<p>指向对应 <span class="t-lc"><a href="cpp-error-errno.html">errno</a></span> 错误码 <code>errnum</code> 的空终止字节串的指针。</p>
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<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
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<p><a rel="nofollow" class="external text" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/strerror.html">POSIX</a> 允许对 <code>strerror</code> 的后继调用非法化先前调用所返回的指针值。它亦指定控制这些消息的 <a href="cpp-locale-LC_categories.html"><tt>LC_MESSAGES</tt></a> 本地环境平面。</p>
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<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
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<div dir="ltr" class="mw-geshi" style="text-align: left;">
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<div class="cpp source-cpp">
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<pre class="de1"><span class="co2">#include <iostream></span>
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<span class="co2">#include <cmath></span>
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<span class="co2">#include <cerrno></span>
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<span class="co2">#include <cstring></span>
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<span class="co2">#include <clocale></span>
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<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
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<span class="br0">{</span>
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<span class="kw4">double</span> not_a_number <span class="sy1">=</span> <a href="cpp-numeric-math-log.html"><span class="kw1323">std::<span class="me2">log</span></span></a><span class="br0">(</span><span class="sy2">-</span><span class="nu16">1.0</span><span class="br0">)</span><span class="sy4">;</span>
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<span class="kw1">if</span> <span class="br0">(</span><span class="kw2">errno</span> <span class="sy1">==</span> <a href="cpp-error-errno_macros.html"><span class="kw810">EDOM</span></a><span class="br0">)</span> <span class="br0">{</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"log(-1) failed: "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">strerror</span><span class="br0">(</span><span class="kw2">errno</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
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<a href="cpp-locale-setlocale.html"><span class="kw1989">std::<span class="me2">setlocale</span></span></a><span class="br0">(</span>LC_MESSAGES, <span class="st0">"de_DE.utf8"</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"Or, in German, "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">strerror</span><span class="br0">(</span><span class="kw2">errno</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
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<span class="br0">}</span>
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<span class="br0">}</span></pre></div>
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</div>
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<p>可能的输出：</p>
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<div dir="ltr" class="mw-geshi" style="text-align: left;">
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<div class="text source-text">
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<pre class="de1">log(-1) failed: Numerical argument out of domain
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Or, in German, Das numerische Argument ist ausserhalb des Definitionsbereiches</pre></div>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
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<table class="t-dsc-begin">
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<td>
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<div class="t-dsc-member-div">
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<div><a href="cpp-io-c-perror.html"><span class="t-lines"><span>perror</span></span></a></div>
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</div>
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</td>
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<td>显示对应当前错误的字符串于 <span class="t-lc"><a href="cpp-io-c.html">stderr</a></span><br />
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<span class="t-mark">(函数)</span></td>
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<div class="t-dsc-member-div">
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<div><a href="cpp-error-errno_macros.html"><span class="t-lines"><span>E2BIG, EACCES, ..., EXDEV</span></span></a></div>
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</div>
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</td>
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<td>兼容标准 POSIX 的错误条件的宏<br />
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<span class="t-mark">(宏常量)</span></td>
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</div>
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<div class="visualClear"></div>
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</body>
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