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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::filesystem::</span>copy_file</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-filesystem.html">filesystem</a></span></div>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-filesystem.html">&lt;filesystem&gt;</a></code></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> copy_file<span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-filesystem-path.html"><span class="kw2199">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">path</span></span></a><span class="sy3">&amp;</span> from,<br /></span>
<p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw4">const</span> <a href="cpp-filesystem-path.html"><span class="kw2199">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">path</span></span></a><span class="sy3">&amp;</span> to <span class="br0">)</span><span class="sy4">;</span><br />
<span class="kw4">bool</span> copy_file<span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-filesystem-path.html"><span class="kw2199">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">path</span></span></a><span class="sy3">&amp;</span> from,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw4">const</span> <a href="cpp-filesystem-path.html"><span class="kw2199">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">path</span></span></a><span class="sy3">&amp;</span> to,<br /></p>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <a href="cpp-error-error_code.html"><span class="kw877">std::<span class="me2">error_code</span></span></a><span class="sy3">&amp;</span> ec <span class="br0">)</span><span class="sy4">;</span></div>
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<td>(1)</td>
<td><span class="t-mark-rev t-since-cxx17">(C++17 &#36215;)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> copy_file<span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-filesystem-path.html"><span class="kw2199">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">path</span></span></a><span class="sy3">&amp;</span> from,<br /></span>
<p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw4">const</span> <a href="cpp-filesystem-path.html"><span class="kw2199">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">path</span></span></a><span class="sy3">&amp;</span> to,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <a href="cpp-filesystem-copy_options.html"><span class="kw2242">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">copy_options</span></span></a> options <span class="br0">)</span><span class="sy4">;</span><br />
<span class="kw4">bool</span> copy_file<span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-filesystem-path.html"><span class="kw2199">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">path</span></span></a><span class="sy3">&amp;</span> from,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw4">const</span> <a href="cpp-filesystem-path.html"><span class="kw2199">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">path</span></span></a><span class="sy3">&amp;</span> to,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <a href="cpp-filesystem-copy_options.html"><span class="kw2242">std::<span class="me2">filesystem</span><span class="sy4">::</span><span class="me2">copy_options</span></span></a> options,<br /></p>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <a href="cpp-error-error_code.html"><span class="kw877">std::<span class="me2">error_code</span></span></a><span class="sy3">&amp;</span> ec <span class="br0">)</span><span class="sy4">;</span></div>
</td>
<td>(2)</td>
<td><span class="t-mark-rev t-since-cxx17">(C++17 &#36215;)</span></td>
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<div class="t-li1"><span class="t-li">1)</span> &#40664;&#35748;&#65292;&#31561;&#20215;&#20110;&#20197; <code>copy_options::none</code> &#20026; <code>options</code> &#30340; <span class="t-v">(2)</span></div>
<div class="t-li1"><span class="t-li">2)</span> &#20174; <code>from</code> &#21040; <code>to</code> &#22797;&#21046;&#21333;&#20010;&#25991;&#20214;&#65292;&#20351;&#29992; <code>options</code> &#25152;&#25351;&#31034;&#30340;&#22797;&#21046;&#36873;&#39033;&#12290;&#33509; <code>options</code> &#20013;&#23384;&#22312;&#20219;&#19968; <a href="cpp-filesystem-copy_options.html">copy_options</a> &#36873;&#39033;&#32452;&#20013;&#22810;&#20110;&#19968;&#20010;&#30340;&#36873;&#39033;&#65292;&#21017;&#34892;&#20026;&#26410;&#23450;&#20041;&#65288;&#21363;&#20351;&#22312;&#26080;&#20851;&#20046; <code>copy_file</code> &#30340;&#32452;&#20013;&#65289;&#12290;
<ul>
<li>&#33509; <a href="cpp-filesystem-is_regular_file.html"><tt>!is_regular_file(from)</tt></a> &#65288;&#22240;&#20026;&#28304;&#25991;&#20214;&#19981;&#23384;&#22312;&#25110;&#23427;&#19981;&#26159;&#24120;&#35268;&#25991;&#20214;&#65289;&#65292;&#21017;&#25253;&#21578;&#38169;&#35823;</li>
<li>&#21542;&#21017;&#65292;&#33509;&#30446;&#26631;&#25991;&#20214;&#19981;&#23384;&#22312;&#65292;&#21017;</li>
</ul>
<dl>
<dd>
<ul>
<li>&#22797;&#21046; <code>from</code> &#25152;&#35299;&#26512;&#21040;&#30340;&#25991;&#20214;&#30340;&#20869;&#23481;&#21450;&#23646;&#24615;&#21040; <code>to</code> &#25152;&#35299;&#26512;&#21040;&#32773;&#65288;&#36319;&#38543;&#31526;&#21495;&#38142;&#25509;&#65289;</li>
</ul>
</dd>
</dl>
<ul>
<li>&#21542;&#21017;&#65292;&#33509;&#30446;&#26631;&#25991;&#20214;&#24050;&#23384;&#22312;&hellip;&hellip;</li>
</ul>
<dl>
<dd>
<ul>
<li>&#33509;&#19979;&#21015;&#20043;&#19968;&#20026;&#30495;&#21017;&#25253;&#21578;&#38169;&#35823;&#65306;</li>
</ul>
<dl>
<dd>
<ul>
<li><code>to</code> &#19982; <code>from</code> &#30456;&#21516;&#65292;&#20197; <a href="cpp-filesystem-equivalent.html"><tt>equivalent(from, to)</tt></a> &#30830;&#23450;&#65307;</li>
<li><code>to</code> &#19981;&#26159;&#24120;&#35268;&#25991;&#20214;&#65292;&#20197; <a href="cpp-filesystem-is_regular_file.html"><tt>!is_regular_file(to)</tt></a> &#30830;&#23450;</li>
<li><code>options</code> &#20013;&#26410;&#35774;&#32622;&#20219;&#20309; <code>copy_file</code> &#25511;&#21046;&#36873;&#39033;</li>
</ul>
</dd>
</dl>
<ul>
<li>&#21542;&#21017;&#65292;&#33509; <code>copy_options::skip_existing</code> &#35774;&#32622;&#20110; <code>options</code> &#65292;&#21017;&#19981;&#20570;&#20219;&#20309;&#20107;</li>
<li>&#21542;&#21017;&#65292;&#33509; <code>copy_options::overwrite_existing</code> &#35774;&#32622;&#20110; <code>options</code> &#65292;&#21017;&#22797;&#21046; <code>from</code> &#25152;&#35299;&#26512;&#21040;&#30340;&#25991;&#20214;&#30340;&#20869;&#23481;&#21450;&#23646;&#24615;&#21040; <code>to</code> &#25152;&#35299;&#26512;&#21040;&#30340;&#25991;&#20214;</li>
<li>&#21542;&#21017;&#65292;&#33509; <code>copy_options::update_existing</code> &#35774;&#32622;&#20110; <code>options</code> &#65292;&#21017;&#20165;&#33509; <code>from</code> &#25353; <a href="cpp-filesystem-last_write_time.html"><tt>last_write_time()</tt></a> &#23450;&#20041;&#26032;&#20110; <code>to</code> &#25165;&#22797;&#21046;</li>
</ul>
</dd>
</dl>
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<p>&#33509;&#38169;&#35823;&#21457;&#29983;&#65292;&#21017;&#19981;&#25243;&#20986;&#37325;&#36733;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span> &#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
<table class="t-par-begin">
<tr class="t-par">
<td>from</td>
<td>-</td>
<td>&#28304;&#25991;&#20214;&#30340;&#36335;&#24452;</td>
</tr>
<tr class="t-par">
<td>to</td>
<td>-</td>
<td>&#30446;&#26631;&#25991;&#20214;&#30340;&#36335;&#24452;</td>
</tr>
<tr class="t-par">
<td>ec</td>
<td>-</td>
<td>&#19981;&#25243;&#20986;&#37325;&#36733;&#20013;&#25253;&#21578;&#38169;&#35823;&#30340;&#36755;&#20986;&#21442;&#25968;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p>&#33509;&#25991;&#20214;&#34987;&#22797;&#21046;&#21017;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> &#65292;&#21542;&#21017;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span> &#12290;</p>
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">&#24322;&#24120;</span></h3>
<p>&#19981;&#25509;&#21463; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-error-error_code.html"><span class="kw877">std::<span class="me2">error_code</span></span></a><span class="sy3">&amp;</span></span></span> &#21442;&#25968;&#30340;&#37325;&#36733;&#22312;&#24213;&#23618; OS API &#38169;&#35823;&#26102;&#25243;&#20986; <a href="cpp-filesystem-filesystem_error.html"><tt>filesystem_error</tt></a> &#65292;&#20197;&#31532;&#19968; path &#21442;&#25968; <code>from</code>&#65292;&#31532;&#20108; path &#21442;&#25968; <code>to</code> &#21644;&#20316;&#20026;&#38169;&#35823;&#30721;&#21442;&#25968;&#30340; OS &#38169;&#35823;&#30721;&#26500;&#36896;&#12290;&#33509; OS API &#35843;&#29992;&#22833;&#36133;&#65292;&#21017;&#25509;&#21463; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-error-error_code.html"><span class="kw877">std::<span class="me2">error_code</span></span></a><span class="sy3">&amp;</span></span></span> &#21442;&#25968;&#30340;&#37325;&#36733;&#35774;&#32622;&#35813;&#21442;&#25968;&#20026; OS API &#38169;&#35823;&#30721;&#65292;&#32780;&#33509;&#19981;&#20986;&#29616;&#38169;&#35823;&#21017;&#25191;&#34892; <span class="t-c"><span class="mw-geshi cpp source-cpp">ec.<span class="me1">clear</span><span class="br0">(</span><span class="br0">)</span></span></span> &#12290;&#33509;&#20869;&#23384;&#20998;&#37197;&#22833;&#36133;&#65292;&#21017;&#20219;&#20309;&#19981;&#26631;&#35760;&#20026; <code>noexcept</code> &#30340;&#37325;&#36733;&#21487;&#33021;&#25243;&#20986; <span class="t-lc"><a href="cpp-memory-new-bad_alloc.html">std::bad_alloc</a></span> &#12290;</p>
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">&#27880;&#24847;</span></h3>
<p>&#20989;&#25968;&#26368;&#22810;&#24341;&#20837;&#19968;&#27425;&#23545; <a href="cpp-filesystem-status.html"><tt>status(to)</tt></a> &#30340;&#30452;&#25509;&#25110;&#38388;&#25509;&#35843;&#29992;&#65288;&#22343;&#29992;&#20110;&#30830;&#23450;&#25991;&#20214;&#26159;&#21542;&#23384;&#22312;&#65292;&#21450;&#23545;&#20110; <code>copy_options::update_existing</code> &#36873;&#39033;&#65292;&#30830;&#23450;&#20854;&#26368;&#21518;&#20889;&#20837;&#26102;&#38388;&#65289;</p>
<p>&#24403; <code>copy_file</code> &#34987;&#29992;&#20110;&#22797;&#21046;&#30446;&#24405;&#26102;&#25253;&#21578;&#38169;&#35823;&#65306;&#29992; <a href="cpp-filesystem-copy.html"><tt>copy</tt></a> &#22797;&#21046;&#23427;&#20204;&#12290;</p>
<p><code>copy_file</code> &#36319;&#38543;&#31526;&#21495;&#38142;&#25509;&#65306;&#29992; <a href="cpp-filesystem-copy_symlink.html"><tt>copy_symlink</tt></a> &#25110; <a href="cpp-filesystem-copy.html"><tt>copy</tt></a> &#24102; <code>copy_options::copy_symlinks</code> &#22797;&#21046;&#23427;&#20204;&#12290;</p>
<h3><span class="mw-headline" id=".E7.BC.BA.E9.99.B7.E6.8A.A5.E5.91.8A">&#32570;&#38519;&#25253;&#21578;</span></h3>
<p>&#19979;&#21015;&#26356;&#25913;&#34892;&#20026;&#30340;&#32570;&#38519;&#25253;&#21578;&#36861;&#28335;&#22320;&#24212;&#29992;&#20110;&#20197;&#21069;&#20986;&#29256;&#30340; C++ &#26631;&#20934;&#12290;</p>
<table class="dsctable" style="font-size:0.8em">
<tr>
<th>DR</th>
<th>&#24212;&#29992;&#20110;</th>
<th>&#20986;&#29256;&#26102;&#30340;&#34892;&#20026;</th>
<th>&#27491;&#30830;&#34892;&#20026;</th>
</tr>
<tr>
<td><a rel="nofollow" class="external text" href="https://cplusplus.github.io/LWG/issue3014">LWG 3014</a></td>
<td>C++17</td>
<td><code>error_code</code> &#37325;&#36733;&#34987;&#26631;&#35760;&#20026; noexcept &#20294;&#33021;&#20998;&#37197;&#20869;&#23384;</td>
<td>&#31227;&#38500; noexcept</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</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="cpp source-cpp">
<pre class="de1"><span class="co2">#include &lt;fstream&gt;</span>
<span class="co2">#include &lt;iostream&gt;</span>
<span class="co2">#include &lt;filesystem&gt;</span>
<span class="kw1">namespace</span> fs <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">filesystem</span><span class="sy4">;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
fs<span class="sy4">::</span><span class="me2">create_directory</span><span class="br0">(</span><span class="st0">&quot;sandbox&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-io-basic_ofstream.html"><span class="kw1733">std::<span class="me2">ofstream</span></span></a><span class="br0">(</span><span class="st0">&quot;sandbox/file1.txt&quot;</span><span class="br0">)</span>.<span class="me1">put</span><span class="br0">(</span><span class="st0">&#39;a&#39;</span><span class="br0">)</span><span class="sy4">;</span>
fs<span class="sy4">::</span><span class="me2">copy_file</span><span class="br0">(</span><span class="st0">&quot;sandbox/file1.txt&quot;</span>, <span class="st0">&quot;sandbox/file2.txt&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="co1">// &#29616;&#22312; sandbox &#20013;&#26377;&#20108;&#20010;&#25991;&#20214;&#65306;</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;file1.txt holds : &quot;</span>
<span class="sy1">&lt;&lt;</span> <a href="cpp-io-basic_ifstream.html"><span class="kw1732">std::<span class="me2">ifstream</span></span></a><span class="br0">(</span><span class="st0">&quot;sandbox/file1.txt&quot;</span><span class="br0">)</span>.<span class="me1">rdbuf</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;file2.txt holds : &quot;</span>
<span class="sy1">&lt;&lt;</span> <a href="cpp-io-basic_ifstream.html"><span class="kw1732">std::<span class="me2">ifstream</span></span></a><span class="br0">(</span><span class="st0">&quot;sandbox/file2.txt&quot;</span><span class="br0">)</span>.<span class="me1">rdbuf</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="co1">// &#22797;&#21046;&#30446;&#24405;&#22833;&#36133;</span>
fs<span class="sy4">::</span><span class="me2">create_directory</span><span class="br0">(</span><span class="st0">&quot;sandbox/abc&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">try</span> <span class="br0">{</span>
fs<span class="sy4">::</span><span class="me2">copy_file</span><span class="br0">(</span><span class="st0">&quot;sandbox/abc&quot;</span>, <span class="st0">&quot;sandbox/def&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span> <span class="kw1">catch</span><span class="br0">(</span>fs<span class="sy4">::</span><span class="me2">filesystem_error</span><span class="sy3">&amp;</span> e<span class="br0">)</span> <span class="br0">{</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;Could not copy sandbox/abc: &quot;</span> <span class="sy1">&lt;&lt;</span> e.<span class="me1">what</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="br0">}</span>
fs<span class="sy4">::</span><span class="me2">remove_all</span><span class="br0">(</span><span class="st0">&quot;sandbox&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
</div>
<p>&#21487;&#33021;&#30340;&#36755;&#20986;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="text source-text">
<pre class="de1">file1.txt holds : a
file2.txt holds : a
Could not copy sandbox/abc: copy_file: Is a directory: &quot;sandbox/abc&quot;, &quot;sandbox/def&quot;</pre></div>
</div>
</div>
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-filesystem-copy_options.html"><span class="t-lines"><span>copy_options</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
</div>
</td>
<td>&#25351;&#23450;&#22797;&#21046;&#25805;&#20316;&#30340;&#35821;&#20041;<br />
<span class="t-mark">(&#26522;&#20030;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-filesystem-copy_symlink.html"><span class="t-lines"><span>copy_symlink</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
</div>
</td>
<td>&#22797;&#21046;&#19968;&#20010;&#31526;&#21495;&#38142;&#25509;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-filesystem-copy.html"><span class="t-lines"><span>copy</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
</div>
</td>
<td>&#22797;&#21046;&#25991;&#20214;&#25110;&#30446;&#24405;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
</table>
</div>
<div class="visualClear"></div>
</div>
</div>
</div>
</body>
</html>