Boost：asio捕获信号

asio可以用于捕捉信号

#include <boost/asio.hpp>
#include <iostream>
using namespace boost::asio;
using namespace std;

void signal_handler(boost::asio::signal_set* sig, const boost::system::error_code & err, int signal)
{
    static int s_sigNum = 0;
    s_sigNum++;
    cout<<"recv "<<s_sigNum<<" signal:"<<signal<<endl;
    if(s_sigNum == 1)
    {
        cout<<"register signal again"<<endl;
        auto f = bind(signal_handler, sig, std::placeholders::_1, std::placeholders::_2);
        sig->async_wait(f);
    }
    else
    {
        cout<<"exit"<<endl;
    }
}

int main()
{
    io_service ios;
    boost::asio::signal_set sig(ios, SIGINT);
    sig.add(SIGTERM);
    auto f = bind(signal_handler, &sig, std::placeholders::_1, std::placeholders::_2);
    sig.async_wait(f);
    ios.run();
    return 0;
}

//g++ -o sig ./sig.cpp

编译运行程序：

$ ./sig 
^Crecv 1 signal:2
register signal again
^Crecv 2 signal:2
exit

程序可以捕获信号，并且第一次捕获后会再次注册信号的异步处理

第二次捕获信号后，程序退出