pwc

    A pointer to the resulting wide-character code.

 s

    A pointer to a multibyte character.

 n

    The maximum number of bytes that comprise the multibyte
    character.

 ps

    A pointer to the mbstate_t object. If a NULL pointer is
    specified, the function uses its internal mbstate_t object.
    mbstate_t is an opaque datatype intended to keep the conversion
    state for the state-dependent codesets.