The bcopy function operates on variable-length strings of bytes.
    It copies the value of the length argument, in bytes, from the
    string in the source argument to the string in the destination
    argument.

    Unlike the string functions, there is no checking for null bytes.
    If the length argument is 0 (zero), no bytes are copied.

    Note that bcopy is equivalent to memcpy, which is defined by
    the ANSI C Standard. Therefore, using memcpy is recommended for
    portable programs.