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<div id="contentSub"><span class="subpages">&lt; <a href="c.html">c</a>&lrm; | <a href="c-numeric.html">numeric</a>&lrm; | <a href="c-numeric-fenv.html">fenv</a></span></div>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code>&lt;fenv.h&gt;</code></div>
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<div><span class="mw-geshi c source-c"><span class="kw4">int</span> fetestexcept<span class="br0">(</span> <span class="kw4">int</span> excepts <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>&#30830;&#23450;&#24403;&#21069;&#35774;&#32622;&#20102;&#21738;&#20010;&#25351;&#23450;&#30340;&#28014;&#28857;&#24322;&#24120;&#23376;&#38598;&#12290;&#21442;&#25968; <code>excepts</code> &#26159;<a href="c-numeric-fenv-FE_exceptions.html">&#28014;&#28857;&#24322;&#24120;&#23439;</a>&#30340;&#36880;&#20301;&#25110;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
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<td>excepts</td>
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<td>&#21015;&#20986;&#24453;&#27979;&#35797;&#24322;&#24120;&#26631;&#24535;&#30340;&#20301;&#25513;&#30721;</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>&#21253;&#21547;&#20110; <code>excepts</code> &#32780;&#19988;&#23545;&#24212;&#20110;&#24403;&#21069;&#35774;&#32622;&#30340;&#28014;&#28857;&#24322;&#24120;&#20013;&#30340;&#28014;&#28857;&#24322;&#24120;&#23439;&#30340;&#36880;&#20301;&#25110;&#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;math.h&gt;</span>
<span class="co2">#include &lt;fenv.h&gt;</span>
<span class="co2">#include &lt;float.h&gt;</span>
<span class="co2">#pragma STDC FENV_ACCESS ON</span>
<span class="kw4">void</span> show_fe_exceptions<span class="br0">(</span><span class="kw4">void</span><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">&quot;current exceptions raised: &quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span>fetestexcept<span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw729">FE_DIVBYZERO</span></a><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">&quot; FE_DIVBYZERO&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span>fetestexcept<span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw730">FE_INEXACT</span></a><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">&quot; FE_INEXACT&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span>fetestexcept<span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw731">FE_INVALID</span></a><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">&quot; FE_INVALID&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span>fetestexcept<span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw732">FE_OVERFLOW</span></a><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">&quot; FE_OVERFLOW&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span>fetestexcept<span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw733">FE_UNDERFLOW</span></a><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">&quot; FE_UNDERFLOW&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">if</span><span class="br0">(</span>fetestexcept<span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw728">FE_ALL_EXCEPT</span></a><span class="br0">)</span><span class="sy1">==</span><span class="nu0">0</span><span class="br0">)</span> <a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot; none&quot;</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">&quot;<span class="es1">\n</span>&quot;</span><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="coMULTI">/* &#26174;&#31034;&#40664;&#35748;&#28014;&#28857;&#26631;&#24535;&#38598;&#21512;&#12290; */</span>
show_fe_exceptions<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span>
<span class="coMULTI">/* &#36827;&#34892;&#19968;&#20123;&#24341;&#21457;&#28014;&#28857;&#24322;&#24120;&#30340;&#35745;&#31639;&#12290; */</span>
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot;1.0/0.0 = %f<span class="es1">\n</span>&quot;</span>, <span class="nu16">1.0</span><span class="sy2">/</span><span class="nu16">0.0</span><span class="br0">)</span><span class="sy4">;</span> <span class="coMULTI">/* FE_DIVBYZERO */</span>
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot;1.0/10.0 = %f<span class="es1">\n</span>&quot;</span>, <span class="nu16">1.0</span><span class="sy2">/</span><span class="nu16">10.0</span><span class="br0">)</span><span class="sy4">;</span> <span class="coMULTI">/* FE_INEXACT */</span>
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot;sqrt(-1) = %f<span class="es1">\n</span>&quot;</span>, <a href="c-numeric-math-sqrt.html"><span class="kw665">sqrt</span></a><span class="br0">(</span><span class="sy2">-</span><span class="nu0">1</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span> <span class="coMULTI">/* FE_INVALID */</span>
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot;DBL_MAX*2.0 = %f<span class="es1">\n</span>&quot;</span>, <a href="c-types-limits.html"><span class="kw378">DBL_MAX</span></a><span class="sy2">*</span><span class="nu16">2.0</span><span class="br0">)</span><span class="sy4">;</span> <span class="coMULTI">/* FE_INEXACT FE_OVERFLOW */</span>
<a href="c-io-fprintf.html"><span class="kw850">printf</span></a><span class="br0">(</span><span class="st0">&quot;nextafter(DBL_MIN/pow(2.0,52),0.0) = %.1f<span class="es1">\n</span>&quot;</span>,
<a href="c-numeric-math-nexttoward.html"><span class="kw701">nextafter</span></a><span class="br0">(</span><a href="c-types-limits.html"><span class="kw375">DBL_MIN</span></a><span class="sy2">/</span><a href="c-numeric-math-pow.html"><span class="kw668">pow</span></a><span class="br0">(</span><span class="nu16">2.0</span>,<span class="nu0">52</span><span class="br0">)</span>,<span class="nu16">0.0</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span> <span class="coMULTI">/* FE_INEXACT FE_UNDERFLOW */</span>
show_fe_exceptions<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">return</span> <span class="nu0">0</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
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<p>&#36755;&#20986;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="text source-text">
<pre class="de1">current exceptions raised: none
1.0/0.0 = inf
1.0/10.0 = 0.100000
sqrt(-1) = -nan
DBL_MAX*2.0 = inf
nextafter(DBL_MIN/pow(2.0,52),0.0) = 0.0
current exceptions raised: FE_DIVBYZERO FE_INEXACT FE_INVALID FE_OVERFLOW FE_UNDERFLOW</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">
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<li>C11 &#26631;&#20934;&#65288;ISO/IEC 9899:2011&#65289;&#65306;</li>
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<li>7.6.2.5 The fetestexcept function (p: 211-212)</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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<li>7.6.2.5 The fetestexcept function (p: 192-193)</li>
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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-numeric-fenv-feclearexcept.html"><span class="t-lines"><span>feclearexcept</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div>
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<td>&#28165;&#38500;&#25351;&#23450;&#30340;&#28014;&#28857;&#24322;&#24120;&#29366;&#24577;&#26631;&#24535;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
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