c - 如何使守护进程的子进程在 Linux 中交互？

Question

我想从守护进程中生成一个交互式进程。我怎样才能做到这一点？我尝试了以下代码片段:

int main (int argc, char *argv[])
{
    if (fork()) exit (EXIT_FAILURE) ;
    freopen("/dev/null","w",stderr) ;
    freopen("/dev/null","r",stdin) ;
    freopen("/dev/null","w",stdout) ;
    /*
     */
    if (fork()) exit (EXIT_FAILURE) ;
    pid_t shell_pgrp = getpgrp () ;
    pid_t my_pid = getpid () ;
    int shell_tty = isatty (fileno(stderr)) ?
        dup (fileno(stderr)) : open (ctermid(NULL), O_RDWR|O_NONBLOCK) ;
    shell_tty = fcntl (shell_tty,F_DUPFD,10) ;
    fcntl (shell_tty,F_SETFD,FD_CLOEXEC) ;
    if (shell_tty < 0) exit (EXIT_FAILURE) ;
    if ((shell_pgrp = tcgetpgrp (shell_tty)) != getpgrp()) {
        setpgid (my_pid,shell_pgrp) ;
    }
    if (shell_pgrp < 0) exit (EXIT_FAILURE) ;
    if ((shell_pgrp = tcgetpgrp (shell_tty)) == getpgrp()) {
        signal (SIGTTIN,SIG_IGN) ;
        signal (SIGTTOU,SIG_IGN) ;
        signal (SIGTSTP,SIG_IGN) ;
        signal (SIGHUP ,SIG_IGN) ;
        signal (SIGQUIT,SIG_IGN) ;
        signal (SIGQUIT,SIG_IGN) ;
        if (!tcsetpgrp (shell_tty,shell_pgrp)) {
            argv++ ;
            if (execv(argv[0],argv) < 0) {
                exit (EXIT_FAILURE) ;
            }
        }
    }
}

Answer 1

我自己从未尝试过，但我不认为复制标准文件描述符将起作用。我相信您生成的进程需要获得一个新的控制终端。 This API 可能会对您有所帮助。