IO.console

static VALUE
console_dev(int argc, VALUE *argv, VALUE klass)
{
    VALUE con = 0;
    VALUE sym = 0;

    rb_check_arity(argc, 0, UNLIMITED_ARGUMENTS);

    if (argc) {
        Check_Type(sym = argv[0], T_SYMBOL);
    }

    // Force the class to be File.
    if (klass == rb_cIO) klass = rb_cFile;

    if (console_dev_get(klass, &con)) {
        if (!RB_TYPE_P(con, T_FILE) || RTEST(rb_io_closed_p(con))) {
            console_dev_remove(klass);
            con = 0;
        }
    }

    if (sym) {
        if (sym == ID2SYM(id_close) && argc == 1) {
            if (con) {
                rb_io_close(con);
                console_dev_remove(klass);
                con = 0;
            }
            return Qnil;
        }
    }

    if (!con) {
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H || defined HAVE_SGTTY_H
# define CONSOLE_DEVICE "/dev/tty"
#elif defined _WIN32
# define CONSOLE_DEVICE "con$"
# define CONSOLE_DEVICE_FOR_READING "conin$"
# define CONSOLE_DEVICE_FOR_WRITING "conout$"
#endif
#ifndef CONSOLE_DEVICE_FOR_READING
# define CONSOLE_DEVICE_FOR_READING CONSOLE_DEVICE
#endif
#ifdef CONSOLE_DEVICE_FOR_WRITING
        VALUE out;
#endif
        int fd;
        VALUE path = rb_obj_freeze(rb_str_new2(CONSOLE_DEVICE));

#ifdef CONSOLE_DEVICE_FOR_WRITING
        fd = rb_cloexec_open(CONSOLE_DEVICE_FOR_WRITING, O_RDWR, 0);
        if (fd < 0) return Qnil;
        out = rb_io_open_descriptor(klass, fd, FMODE_WRITABLE | FMODE_SYNC, path, Qnil, NULL);
#endif
        fd = rb_cloexec_open(CONSOLE_DEVICE_FOR_READING, O_RDWR, 0);
        if (fd < 0) {
#ifdef CONSOLE_DEVICE_FOR_WRITING
            rb_io_close(out);
#endif
            return Qnil;
        }

        con = rb_io_open_descriptor(klass, fd, FMODE_READWRITE | FMODE_SYNC, path, Qnil, NULL);
#ifdef CONSOLE_DEVICE_FOR_WRITING
        rb_io_set_write_io(con, out);
#endif
        console_dev_set(klass, con);
    }

    if (sym) {
        return rb_f_send(argc, argv, con);
    }

    return con;
}