1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Signal Handling</title> 5<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../boost_asio.html" title="Boost.Asio"> 8<link rel="up" href="../overview.html" title="Overview"> 9<link rel="prev" href="serial_ports.html" title="Serial Ports"> 10<link rel="next" href="posix.html" title="POSIX-Specific Functionality"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 15<td align="center"><a href="../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="serial_ports.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../overview.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="posix.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h3 class="title"> 27<a name="boost_asio.overview.signals"></a><a class="link" href="signals.html" title="Signal Handling">Signal Handling</a> 28</h3></div></div></div> 29<p> 30 Boost.Asio supports signal handling using a class called <a class="link" href="../reference/signal_set.html" title="signal_set">signal_set</a>. 31 Programs may add one or more signals to the set, and then perform an <code class="computeroutput">async_wait()</code> 32 operation. The specified handler will be called when one of the signals occurs. 33 The same signal number may be registered with multiple <a class="link" href="../reference/signal_set.html" title="signal_set">signal_set</a> 34 objects, however the signal number must be used only with Boost.Asio. 35 </p> 36<pre class="programlisting">void handler( 37 const boost::system::error_code& error, 38 int signal_number) 39{ 40 if (!error) 41 { 42 // A signal occurred. 43 } 44} 45 46... 47 48// Construct a signal set registered for process termination. 49boost::asio::signal_set signals(io_context, SIGINT, SIGTERM); 50 51// Start an asynchronous wait for one of the signals to occur. 52signals.async_wait(handler); 53</pre> 54<p> 55 Signal handling also works on Windows, as the Microsoft Visual C++ runtime 56 library maps console events like Ctrl+C to the equivalent signal. 57 </p> 58<h5> 59<a name="boost_asio.overview.signals.h0"></a> 60 <span class="phrase"><a name="boost_asio.overview.signals.see_also"></a></span><a class="link" href="signals.html#boost_asio.overview.signals.see_also">See 61 Also</a> 62 </h5> 63<p> 64 <a class="link" href="../reference/signal_set.html" title="signal_set">signal_set</a>, <a class="link" href="../examples/cpp03_examples.html#boost_asio.examples.cpp03_examples.http_server">HTTP server example 65 (C++03)</a>, <a class="link" href="../examples/cpp11_examples.html#boost_asio.examples.cpp11_examples.http_server">HTTP 66 server example (C++11)</a>. 67 </p> 68</div> 69<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 70<td align="left"></td> 71<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 72 Kohlhoff<p> 73 Distributed under the Boost Software License, Version 1.0. (See accompanying 74 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 75 </p> 76</div></td> 77</tr></table> 78<hr> 79<div class="spirit-nav"> 80<a accesskey="p" href="serial_ports.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../overview.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="posix.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 81</div> 82</body> 83</html> 84
