The ldap_first_message() and ldap_next_message()  functions are
    used to step through the list of messages in a result chain
    returned by ldap_result(). For search operations, the result
    chain may actually include referral messages, entry messages,
    and result messages. The ldap_count_messages() function is used
    to count the number of messages returned. The ldap_msgtype()
    function can be used to distinguish between the different message
    types.

     LDAPMessage *ldap_first_message( LDAP *ld, LDAPMessage *res );
     LDAPMessage *ldap_next_message ( LDAP *ld, LDAPMesage *msg );
     int ldap_count_messages( LDAP *ld, LDAPMessage *res );

    Parameters are as follows:

    ld    The session handle.
    res   The result chain, as obtained by a call to one of the
          synchronous search functions or ldap_result().
    msg   The message returned by a previous call to ldap_first_
          message()  or ldap_next_message().

    The ldap_first_message() and ldap_next_message()  functions will
    return NULL when no more messages exist in the result set to be
    returned. NULL is also returned if an error occurs while stepping
    through the entries, in which case the error parameters in the
    session handle ld will be set to indicate the error.

    The ldap_count_messages() function returns the number of messages
    contained in a chain of results. It can also be used to count
    the number of messages that remain in a chain if called with a
    message, entry, or reference returned by ldap_first_message(),
    ldap_next_message(), ldap_first_entry(),  ldap_next_entry(),
    ldap_first_reference(), ldap_next_reference().