213 lines
9.7 KiB
HTML
213 lines
9.7 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>fgetc, getc</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_io_fgetc skin-cppreference2 action-view cpp-navbar">
|
|
<div id="cpp-content-base">
|
|
<div id="content"><a id="top"></a>
|
|
<h1 id="firstHeading" class="firstHeading">fgetc, getc</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="c.html">c</a>‎ | <a href="c-io.html">io</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><stdio.h></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl">
|
|
<td>
|
|
<div><span class="mw-geshi c source-c"><span class="kw4">int</span> fgetc<span class="br0">(</span> <a href="c-io.html"><span class="kw882">FILE</span></a> <span class="sy2">*</span>stream <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(1)</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
</tr>
|
|
<tr class="t-dcl">
|
|
<td>
|
|
<div><span class="mw-geshi c source-c"><span class="kw4">int</span> getc<span class="br0">(</span> <a href="c-io.html"><span class="kw882">FILE</span></a> <span class="sy2">*</span>stream <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(2)</td>
|
|
<td class="t-dcl-nopad"></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> 从给定的输入流读取下一个字符。</div>
|
|
<div class="t-li1"><span class="t-li">2)</span> 同 <code>fgetc</code> ,除了若 <code>getc</code> 实现为宏,则它可能求值 stream 多于一次,所以实参始终不应为带有副作用的表达式。</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>stream</td>
|
|
<td>-</td>
|
|
<td>读取字符的来源</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p>成功时为作为 <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">unsigned</span> <span class="kw4">char</span></span></span> 获得并转换为 <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">int</span></span></span> 的字符,失败时为 <span class="t-lc"><a href="c-io.html">EOF</a></span> 。</p>
|
|
<p>若文件尾条件导致失败,则另外设置 <code>stream</code> 上的<i>文件尾</i>指示器(见 <span class="t-lc"><a href="c-io-feof.html">feof()</a></span> )。若某些其他错误导致失败,则设置 <code>stream</code> 上的<i>错误</i>指示器(见 <span class="t-lc"><a href="c-io-ferror.html">ferror()</a></span> )。</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 <stdio.h></span>
|
|
<span class="co2">#include <stdlib.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>
|
|
<a href="c-io.html"><span class="kw882">FILE</span></a><span class="sy2">*</span> fp <span class="sy1">=</span> <a href="c-io-fopen.html"><span class="kw819">fopen</span></a><span class="br0">(</span><span class="st0">"test.txt"</span>, <span class="st0">"r"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">if</span><span class="br0">(</span><span class="sy3">!</span>fp<span class="br0">)</span> <span class="br0">{</span>
|
|
<a href="c-io-perror.html"><span class="kw877">perror</span></a><span class="br0">(</span><span class="st0">"File opening failed"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">return</span> <a href="c-program-EXIT_status.html"><span class="kw494">EXIT_FAILURE</span></a><span class="sy4">;</span>
|
|
<span class="br0">}</span>
|
|
|
|
<span class="kw4">int</span> c<span class="sy4">;</span> <span class="co1">// 注意:int,非char,要求处理EOF</span>
|
|
<span class="kw1">while</span> <span class="br0">(</span><span class="br0">(</span>c <span class="sy1">=</span> fgetc<span class="br0">(</span>fp<span class="br0">)</span><span class="br0">)</span> <span class="sy3">!</span><span class="sy1">=</span> <a href="c-io.html"><span class="kw887">EOF</span></a><span class="br0">)</span> <span class="br0">{</span> <span class="co1">// 标准C I/O读取文件循环</span>
|
|
<a href="c-io-putchar.html"><span class="kw833">putchar</span></a><span class="br0">(</span>c<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span>
|
|
|
|
<span class="kw1">if</span> <span class="br0">(</span><a href="c-io-ferror.html"><span class="kw876">ferror</span></a><span class="br0">(</span>fp<span class="br0">)</span><span class="br0">)</span>
|
|
<a href="c-io-puts.html"><span class="kw834">puts</span></a><span class="br0">(</span><span class="st0">"I/O error when reading"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">else</span> <span class="kw1">if</span> <span class="br0">(</span><a href="c-io-feof.html"><span class="kw875">feof</span></a><span class="br0">(</span>fp<span class="br0">)</span><span class="br0">)</span>
|
|
<a href="c-io-puts.html"><span class="kw834">puts</span></a><span class="br0">(</span><span class="st0">"End of file reached successfully"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
|
|
<a href="c-io-fclose.html"><span class="kw822">fclose</span></a><span class="br0">(</span>fp<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span></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-17">
|
|
<ul>
|
|
<li>C17 标准(ISO/IEC 9899:2018):</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.21.7.1 The fgetc function (p: 240-241)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.21.7.5 The getc function (p: 242)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<div class="t-ref-std-11">
|
|
<ul>
|
|
<li>C11 标准(ISO/IEC 9899:2011):</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.21.7.1 The fgetc function (p: 330)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.21.7.5 The getc function (p: 332)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<div class="t-ref-std-c99">
|
|
<ul>
|
|
<li>C99 标准(ISO/IEC 9899:1999):</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.19.7.1 The fgetc function (p: 296)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.19.7.5 The getc function (p: 297-298)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<div class="t-ref-std-c89">
|
|
<ul>
|
|
<li>C89/C90 标准(ISO/IEC 9899:1990):</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>4.9.7.1 The fgetc function</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>4.9.7.5 The getc function</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-io-getchar.html"><span class="t-lines"><span>getchar</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>从 <span class="t-lc"><a href="c-io.html">stdin</a></span> 读取一个字符<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-io-gets.html"><span class="t-lines"><span>gets</span><span>gets_s</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-until-c11">(C11 中移除)</span></span><span><span class="t-mark-rev t-since-c11">(C11)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>从 <code>stdin</code> 读取一个字符串<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-io-fputc.html"><span class="t-lines"><span>fputc</span><span>putc</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>将一个字符写入文件流<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-io-ungetc.html"><span class="t-lines"><span>ungetc</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>将一个字符送回文件流<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|