readable_real?

static VALUE
rb_stat_R(VALUE obj)
{
    struct stat *st = get_stat(obj);

#ifdef USE_GETEUID
    if (getuid() == 0) return Qtrue;
#endif
#ifdef S_IRUSR
    if (rb_stat_rowned(obj))
        return st->st_mode & S_IRUSR ? Qtrue : Qfalse;
#endif
#ifdef S_IRGRP
    if (rb_group_member(get_stat(obj)->st_gid))
        return st->st_mode & S_IRGRP ? Qtrue : Qfalse;
#endif
#ifdef S_IROTH
    if (!(st->st_mode & S_IROTH)) return Qfalse;
#endif
    return Qtrue;
}