PLSQL NOTE--------network utl_inaddr package

（1）获取本地主机名(host_name)和地址(host_address)

 SET serveroutput on
 BEGIN
   DBMS_OUTPUT.PUT_LINE(UTL_INADDR.GET_HOST_NAME);  -- get local host name
   DBMS_OUTPUT.PUT_LINE(UTL_INADDR.GET_HOST_ADDRESS);  -- get local IP addr
 END;
 /

（2）根据host_name 获取address或根据address取name

  UTL_INADDR.GET_HOST_ADDRESS ( host  IN VARCHAR2 DEFAULT NULL) 
  RETURN host_address VARCHAR2; 
  --host       The name of the host to retrieve the IP address.
  --host_address     The IP address of the specified host, or that of the local host if host is NULL.
  
  
  UTL_INADDR.GET_HOST_NAME ( ip  IN VARCHAR2 DEFAULT NULL)
 RETURN host_name VARCHAR2;
  --ip     The IP address of the host used to determine its host name. If ip is not NULL, the official name of the host with its domain name is returned. 
　 --If this is NULL, the name of the local host is returned and the name does not contain the domain to which the local host belongs.
 
 --host_name        The name of the local or remote host of the specified IP address.