The gethostbyname_r function is the reentrant version of
    gethostbyname. The caller supplies a hostent structure ret which
    will be filled in on success, and a temporary work buffer buffer
    of size buflen. After the call, result will point to the result
    on success. In case of an error or if no entry is found result
    will be NULL. The functions return 0 on success and a nonzero
    error number on failure. In addition to the errors returned by
    the nonreentrant version, if buffer is too small, the functions
    will return ERANGE, and the call should be retried with a larger
    buffer. The global variable h_errno is not modified, but the
    address of a variable in which to store error numbers is passed
    in h_errnop.

    Note: Modules which include calls to gethostbyname or
    gethostbyname_r must be compiled with the C switch /PREFIX=ALL.