在C ++中，当被ctrl-c中断时，在死亡之前调用带有参数(信号编号除外)的函数 [英] In C++ when interrupted with ctrl-c call a function with arguments (other than signal number) before dying

问题描述

在程序终止之前，当我用ctrl-c中断时，我想在文件中写一些额外的行.但是该文件的位置不是硬编码的，因此除了正常的中断处理外，我还需要一些其他功能

I want to write a few extra lines to a file when interrupted with ctrl-c before the program dies. However the location of the file is not hard coded so I need something more than normal interrupt handling as explained here. What is the best way to do this?

动机:
我正在做时间相关的有限元模拟.有时，我忘记或错误估计了合理的tmax，并且仿真将花费很长时间才能完成，因此我用ctrl-c中断了它.但是，我仍然想使用到目前为止生成的数据.特别是，有一个xml文件，需要在模拟完成后添加几行以关闭标签.当然，可以手动执行此操作，但这很痛苦，因此，我尝试使其自动化.

Motivation:
I'm doing time dependent finite element simulations. Sometimes I forget or mis-estimate a reasonable tmax and the simulation would take a very long time to complete, so I interrupt it with ctrl-c. However I still want to use the data generated up to that point. In particular there's an xml file which needs a few lines appended after the simulation is finished to close the tags. Of course it's possible to do this by hand but it's a pain, so I'm try to automate it.

推荐答案

基于对"

Based on the answer to "How can I catch a ctrl-c event? (C++)" we can install a signal handler that simply raises an exception. Then we can catch the exception and run whatever standard c++ code we like.

这是一个可行的示例:

#include <iostream>
#include <exception>
#include <signal.h>
#include <stdlib.h>


class InterruptException : public std::exception
{
public:
  InterruptException(int s) : S(s) {}
  int S;
};


void sig_to_exception(int s)
{
  throw InterruptException(s);
}


int main()
  {
    // Taken from answer to "How can I catch a ctrl-c event? (C++)"
    struct sigaction sigIntHandler;
    sigIntHandler.sa_handler = sig_to_exception;
    sigemptyset(&sigIntHandler.sa_mask);
    sigIntHandler.sa_flags = 0;
    sigaction(SIGINT, &sigIntHandler, NULL);


    try
      {
        std::cout << "Inside try" << std::endl;

        // Do something with output so the loop doesn't get optimised out
        double i = 0;
        while(i < 1e30) {i++;} // loop until interrupted
        std::cout << i << std::endl;
      }
    catch(InterruptException& e)
      {
        std::cout << "Write something to file" << std::endl;
        std::cout << "Caught signal " << e.S << std::endl;
        return 1;
      }

    return 0;
  }

这种方法确实有至少一个缺点:尝试安装处理程序后，我们必须包装所有内容，否则中断信号将导致abort().

This approach does have at least one downside: we have to wrap everything after the handler is installed in a try, otherwise interrupt signals would cause an abort().

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