typedef struct {
    int fd;
    int fd_new;
    int fd_copy;
    char *filename;
    int flags;
} Redirect;

Redirect in = {.fd = STDIN_FILENO, .fd_new = -1, .fd_copy = -1, .filename = NULL, .flags = O_RDONLY};
Redirect out = {.fd = STDOUT_FILENO, .fd_new = -1, .fd_copy = -1, .filename = NULL, .flags = O_WRONLY | O_CREAT | O_TRUNC};
Redirect err = {.fd = STDERR_FILENO, .fd_new = -1, .fd_copy = -1, .filename = NULL, .flags = O_WRONLY | O_CREAT | O_TRUNC};

void open_redirect(Redirect *redirect) {
    redirect->fd_copy = dup(redirect->fd);
    if (redirect->fd_copy == -1) {
        perror("dup");
    }
    else {
        redirect->fd_new = open(redirect->filename, redirect->flags, 0664);
        if (redirect->fd_new == -1) {
            fprintf(stderr, "open: Could not open file %s: \"%s\"\n", redirect->filename, strerror(errno));
        }
        else {
            if (close(redirect->fd) == -1) {
                perror("close");
            }
            if (dup(redirect->fd_new) == -1) {
                perror("dup");
            }
        }
    }
}

void close_redirect(Redirect *redirect) {
    if (close(redirect->fd_new) == -1) {
        perror("close");
    }
    if (dup2(redirect->fd_copy, redirect->fd) == -1) {
        perror("dup2");
    }
    if (close(redirect->fd_copy) == -1) {
        perror("close");
    }
}