Question

标题不言而喻。这是功能：

void fork_and_chain(int * pipein, int * pipeout, Command *cmd, int size)
{
    auto pid = fork();
    int status;

    if(!pid)
    {
        if(pipein) {
            dup2(pipein[0], 0);
            close(pipein[0]);
            close(pipein[1]);
        } else if (cmd->redirectin) {
            int fin = open(cmd->filename.c_str(), O_RDONLY);
            dup2(fin, 0);
            close(fin);
        }

        if(pipeout) {
            dup2(pipeout[1], 1);
            close(pipeout[0]);
            close(pipeout[1]);
        } else if (cmd->redirectout) {
            int fout = open(cmd->filename.c_str(), O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IRGRP | S_IWGRP | S_IWUSR);
            dup2(fout, 1);
            close(fout);
        }

        if (execvp(cmd->args_char[0], cmd->args_char.data()) < 0) {
            std::cerr << "Command not Found" << std::endl;
        }
    } else if (pid < 0) {
        std::cerr << "Fork failed." << std::endl;
        exit(1);
    } else {
        // waiting for child process to finish
    }
}

无论我放在那里，我都会得到一个无限循环（我正在制作一个shell）。我要么无限地得到“cmd”提示，要么一无所获。链接代码继续运行，我不知道终止它。

Answer 1

我认为你正在寻找waitpid（）。在评论部分添加：

int status = 0;
waitpid(pid, &status, 0);
std::cerr << "child finished with status: " << status << std::endl;

我如何等待子进程结束

1 个答案: