Fiddle::Pointer.read

Fiddle::Pointer.read(address, len) => string

static VALUE
rb_fiddle_ptr_read_mem(VALUE klass, VALUE address, VALUE len)
{
    return rb_str_new((char *)NUM2PTR(address), NUM2ULONG(len));
}

Or read the memory at address address with length len and return a string with that memory

See also .new .to_ptr .malloc .write also in 3.4