c++ - 程序因指针错误意外关闭

Question

我正在从 GUI 创建此类的实例on_click()。它应该fork()是一系列其他过程。它运行良好，直到最后 GUI 关闭并出现错误：

免费（）：无效指针：0x000000000209c608

我理解这意味着程序正在尝试访问一个禁止访问的内存位置。我正在使用 QT creator，但似乎无法让调试器正常工作。这是代码：

scriptfilefeed::scriptfilefeed() { }

scriptfilefeed::scriptfilefeed(vector<vector<vector<string> > > & newFeed, double trimParam1, unsigned int trimParam2)
{
    const string min = "<TMIN>";
    const string max = "<TMAX>";
    bla[0] = "6";
    bla[1] = "47";

    input.clear();

    for (int i = 0; i < newFeed.size(); i++)
    {
        if (i == 1)
        { // then we first need to run trimlowQ to get arguments

        }
        input.clear();

        for (int j = 0; j < newFeed[i].size(); j++)
        {
            for (int k = 0; k < newFeed[i][j].size(); k++)
            {
                curstr = newFeed[i][j][k];
                input.push_back(curstr.c_str());

                if (i == 1 && input.at(j) == min)
                { // const string comp.for trim parameters
                    input.pop_back(); // remove last element
                    input.push_back(bla[0]); // insert this instead
                }

                if (i == 1 && input.at(j) == max)
                {
                    input.pop_back(); // remove last element
                    input.push_back(bla[1]);
                }
                cout << newFeed[i][j][k] << endl;
            }

        }

        while (input.size() <= 13)
        {
            input.push_back(0);
        }

        cout << "Starting Process: " << input.at(1) << endl;
        child = fork();

        int ret;
        if (child == 0)
        {
            ret = execl(input.at(0), input.at(1), input.at(2), input.at(3), input.at(4), input.at(5), input.at(6), input.at(7), input.at(8), input.at(9), input.at(10), input.at(11), input.at(12));
            printf("failed... ret=%d\n", ret);
            perror("this error occured:");
        }

        bool childEnded = false;
        while (childEnded == false)
        {
            int status;
            int result = waitpid(child, &status, WNOHANG);
            if (result == 0)
            {
                // keep going
            }
            else if (result == -1)
            {
                // continue
            }
            else
            {
                childEnded = true;
                cout << "Process Finished" << endl;
            }
        }
    }
}