C++ 子进程中的数组分配无效

我有一个定制的“迷你shell”的代码，在这个代码中，我在子进程中将用户提供的字符串解析为终端中的单个单词

以下是子代码：

child_pid = fork();

            if (child_pid == 0)
            {
                char* args[100];
                int   prev_pos = 0;
                int   pos;
                int   i = 0;

                cout << "Inside loop" << endl;
                while((pos = command.find(" ", prev_pos)) != string::npos)
                {
                    //cout << command.substr(prev_pos, pos) << endl;
                    if (i >= 1)
                    {
                        cout << endl << "Before Assignment: " << i - 1 << "   " << args[i - 1] <<"kwe"<< endl;
                    }

                    args[i] = const_cast<char*>((command.substr(prev_pos, (pos - prev_pos))).c_str());
                    cout << i << "   " << args[i] <<"befre cndition aftr ass"<< endl;
                    //cout << command.substr(prev_pos, pos) << endl;
                    if (i >= 1)
                    {
                        int j=i-1;
                        cout << "After Assignment: "<< i - 1 << "   " << args[j] <<"eefe"<< endl;
                    }
                    cout << i << "   " << args[i] << endl;

                    if (i >= 1)
                    {
                        for (int j = 0; j <= i; j++)
                        {
                            cout << "\t" << j << "   " << args[j] << endl;
                        }
                    }

                    prev_pos = (pos + 1);
                    i++;

                }// 'while' loop


                args[i] = const_cast<char*>((command.substr(prev_pos)).c_str());
                cout << i << "   " << args[i] << endl;
                i++;

                cout << "Outside loop" << endl << endl;
                cout << *(args + 0) << endl << endl;
                for (int j = 0; j < i; j++)
                {
                    cout << j << "   " << args[j] << endl;
                }

                args[i] = NULL;

                cout << endl << endl << args[0] << endl << endl;
                //execvpe(args[0], args, envp);

                cout << "Unknown command\n";
                exit(0);

            }// 'if'

---

为什么会这样？如何修改代码，以便在while循环结束时，将每个单词存储到arg[I]中？提前谢谢

问题在于：

args[i] = const_cast<char*>((command.substr(prev_pos, (pos - prev_pos))).c_str());

args[i]=const_cast（（command.substr（prev_pos，（pos-prev_pos）））.c_str（）；

substr

函数返回一个string对象，其中有一个指针，然后string对象被销毁，留下一个指向不再存在的数据的散乱指针。这将导致严重的后果

您需要为字符串分配内存以使其永久化

args[i] = const_cast<char*>((command.substr(prev_pos, (pos - prev_pos))).c_str());