End of Life Ruby 3.0 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

class method

IO.binwrite

IO.binwrite(name, string, [offset] ) → integer

IO.binwrite(name, string, [offset], open_args ) → integer

static VALUE
rb_io_s_binwrite(int argc, VALUE *argv, VALUE io)
{
    return io_s_write(argc, argv, io, 1);
}

Same as IO.write except opening the file in binary mode and ASCII-8BIT encoding ("wb:ASCII-8BIT").

See also .binread .console .console_size also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.1