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<h1 id="firstHeading" class="firstHeading">fgetpos</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="c.html">c</a>&lrm; | <a href="c-io.html">io</a></span></div>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;stdio.h&gt;</code></div>
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<div><span class="mw-geshi c source-c"><span class="kw4">int</span> fgetpos<span class="br0">(</span> <a href="c-io.html"><span class="kw883">FILE</span></a> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="sy2">*</span>stream, <a href="c-io.html"><span class="kw884">fpos_t</span></a> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="sy2">*</span>pos <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-until-c99">(C99 &#21069;)</span></td>
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<div><span class="mw-geshi c source-c"><span class="kw4">int</span> fgetpos<span class="br0">(</span> <a href="c-io.html"><span class="kw883">FILE</span></a> <span class="sy2">*</span><span class="kw4">restrict</span> stream, <a href="c-io.html"><span class="kw884">fpos_t</span></a> <span class="sy2">*</span><span class="kw4">restrict</span> pos <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-c99">(C99 &#36215;)</span></td>
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<p>&#33719;&#24471;&#25991;&#20214;&#27969; <code>stream</code> &#30340;&#25991;&#20214;&#20301;&#32622;&#25351;&#31034;&#22120;&#21644;&#24403;&#21069;&#20998;&#26512;&#29366;&#24577;&#65288;&#33509;&#23384;&#22312;&#65289;&#65292;&#24182;&#23558;&#23427;&#20204;&#23384;&#20648;&#20110; <code>pos</code> &#25152;&#25351;&#21521;&#30340;&#23545;&#35937;&#12290;&#23384;&#20648;&#30340;&#20540;&#20165;&#22312;&#20316;&#20026; <span class="t-lc"><a href="c-io-fsetpos.html">fsetpos</a></span> &#30340;&#36755;&#20837;&#30340;&#24773;&#20917;&#26377;&#24847;&#20041;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
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<td>stream</td>
<td>-</td>
<td>&#35201;&#26816;&#39564;&#30340;&#25991;&#20214;&#27969;</td>
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<td>pos</td>
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<td>&#25351;&#21521;&#35201;&#23384;&#20648;&#25991;&#20214;&#20301;&#32622;&#25351;&#31034;&#22120;&#21040;&#30340; <span class="t-c"><span class="mw-geshi c source-c"><a href="c-io.html"><span class="kw884">fpos_t</span></a></span></span> &#23545;&#35937;&#30340;&#25351;&#38024;</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>&#25104;&#21151;&#26102;&#20026; <span class="t-c"><span class="mw-geshi c source-c">&#8203;<span class="nu0">0</span>&#8203;</span></span> &#65292;&#21542;&#21017;&#38750;&#38646;&#20540;&#12290;</p>
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</span></h3>
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<pre class="de1"><span class="co2">#include &lt;stdio.h&gt;</span>
<span class="co2">#include &lt;stdlib.h&gt;</span>
<span class="co2">#include &lt;assert.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="co1">// &#20934;&#22791;&#20445;&#26377; 4 &#20010; double &#31867;&#22411;&#20540;&#30340;&#25991;&#20214;</span>
<span class="kw2">enum</span> <span class="br0">{</span>SIZE <span class="sy1">=</span> <span class="nu0">4</span><span class="br0">}</span><span class="sy4">;</span>
<a href="c-io.html"><span class="kw883">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">&quot;test.bin&quot;</span>, <span class="st0">&quot;wb&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>fp<span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">int</span> rc <span class="sy1">=</span> <a href="c-io-fwrite.html"><span class="kw826">fwrite</span></a><span class="br0">(</span><span class="br0">(</span><span class="kw4">double</span><span class="br0">[</span>SIZE<span class="br0">]</span><span class="br0">)</span><span class="br0">{</span><span class="nu16">1.1</span>, <span class="nu16">2.2</span>, <span class="nu16">3.3</span>, <span class="nu16">4.4</span><span class="br0">}</span>, <span class="kw4">sizeof</span><span class="br0">(</span><span class="kw4">double</span><span class="br0">)</span>, SIZE, fp<span class="br0">)</span><span class="sy4">;</span>
<a href="c-error-assert.html"><span class="kw407">assert</span></a><span class="br0">(</span>rc <span class="sy1">==</span> SIZE<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="co1">// &#28436;&#31034;&#20351;&#29992; fsetpos &#36820;&#22238;&#21040;&#25991;&#20214;&#36215;&#22987;</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">&quot;test.bin&quot;</span>, <span class="st0">&quot;rb&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io.html"><span class="kw884">fpos_t</span></a> pos<span class="sy4">;</span>
fgetpos<span class="br0">(</span>fp, <span class="sy3">&amp;</span>pos<span class="br0">)</span><span class="sy4">;</span> <span class="co1">// &#23384;&#20648;&#25991;&#20214;&#36215;&#22987;&#20110; pos</span>
<span class="kw4">double</span> d<span class="sy4">;</span>
rc <span class="sy1">=</span> <a href="c-io-fread.html"><span class="kw825">fread</span></a><span class="br0">(</span><span class="sy3">&amp;</span>d, <span class="kw4">sizeof</span> d, <span class="nu0">1</span>, fp<span class="br0">)</span><span class="sy4">;</span> <span class="co1">// &#35835;&#21462;&#39318;&#20010; double</span>
<a href="c-error-assert.html"><span class="kw407">assert</span></a><span class="br0">(</span>rc <span class="sy1">==</span> <span class="nu0">1</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw851">printf</span></a><span class="br0">(</span><span class="st0">&quot;First value in the file: %.1f<span class="es1">\n</span>&quot;</span>, d<span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fsetpos.html"><span class="kw873">fsetpos</span></a><span class="br0">(</span>fp,<span class="sy3">&amp;</span>pos<span class="br0">)</span><span class="sy4">;</span> <span class="co1">// &#31227;&#21160;&#25991;&#20214;&#20301;&#32622;&#22238;&#25991;&#20214;&#36215;&#22987;</span>
rc <span class="sy1">=</span> <a href="c-io-fread.html"><span class="kw825">fread</span></a><span class="br0">(</span><span class="sy3">&amp;</span>d, <span class="kw4">sizeof</span> d, <span class="nu0">1</span>, fp<span class="br0">)</span><span class="sy4">;</span> <span class="co1">// &#20877;&#27425;&#35835;&#21462;&#39318;&#20010; double</span>
<a href="c-error-assert.html"><span class="kw407">assert</span></a><span class="br0">(</span>rc <span class="sy1">==</span> <span class="nu0">1</span><span class="br0">)</span><span class="sy4">;</span>
<a href="c-io-fprintf.html"><span class="kw851">printf</span></a><span class="br0">(</span><span class="st0">&quot;First value in the file again: %.1f<span class="es1">\n</span>&quot;</span>, d<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="co1">// &#28436;&#31034;&#38169;&#35823;&#22788;&#29702;</span>
rc <span class="sy1">=</span> <a href="c-io-fsetpos.html"><span class="kw873">fsetpos</span></a><span class="br0">(</span><a href="c-io.html"><span class="kw885">stdin</span></a>, <span class="sy3">&amp;</span>pos<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span>rc<span class="br0">)</span> <a href="c-io-perror.html"><span class="kw878">perror</span></a><span class="br0">(</span><span class="st0">&quot;could not fsetpos stdin&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
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<p>&#36755;&#20986;&#65306;</p>
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<pre class="de1">First value in the file: 1.1
First value in the file again: 1.1
could not fsetpos stdin: Illegal seek</pre></div>
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<h3><span class="mw-headline" id=".E5.BC.95.E7.94.A8">&#24341;&#29992;</span></h3>
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<li>C11 &#26631;&#20934;&#65288;ISO/IEC 9899:2011&#65289;&#65306;</li>
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<li>7.21.9.1 The fgetpos function (p: 336)</li>
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<li>C99 &#26631;&#20934;&#65288;ISO/IEC 9899:1999&#65289;&#65306;</li>
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<li>7.19.9.1 The fgetpos function (p: 302)</li>
</ul>
</dd>
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<div class="t-ref-std-c89">
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<li>C89/C90 &#26631;&#20934;&#65288;ISO/IEC 9899:1990&#65289;&#65306;</li>
</ul>
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<dd>
<ul>
<li>4.9.9.1 The fgetpos function</li>
</ul>
</dd>
</dl>
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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><a href="c-io-ftell.html"><span class="t-lines"><span>ftell</span></span></a></div>
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<td>&#36820;&#22238;&#24403;&#21069;&#30340;&#25991;&#20214;&#20301;&#32622;&#25351;&#31034;&#20540;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
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<div class="t-dsc-member-div">
<div><a href="c-io-fseek.html"><span class="t-lines"><span>fseek</span></span></a></div>
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<td>&#23558;&#25991;&#20214;&#20301;&#32622;&#25351;&#31034;&#31526;&#31227;&#21160;&#21040;&#25991;&#20214;&#20013;&#30340;&#25351;&#23450;&#20301;&#32622;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
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<div><a href="c-io-fsetpos.html"><span class="t-lines"><span>fsetpos</span></span></a></div>
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<td>&#23558;&#25991;&#20214;&#20301;&#32622;&#25351;&#31034;&#22120;&#31227;&#21160;&#21040;&#25991;&#20214;&#20013;&#30340;&#25351;&#23450;&#20301;&#32622;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
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