rb_io_open_generic 6588 io.c           static VALUE rb_io_open_generic(VALUE, int, int, const convconfig_t *, mode_t);
rb_io_open_generic 6599 io.c               return rb_io_open_generic(filename, oflags, fmode, &convconfig, perm);
rb_io_open_generic 9899 io.c               arg.io = rb_io_open_generic(argv[0], oflags, fmode, &convconfig, 0);