or download this
$ head -4 $ORACLE_HOME/network/admin/tnsnames.ora
oradb_btest = ( DESCRIPTION = ( ADDRESS_LIST =
...
Attempting to contact ( DESCRIPTION = ( ADDRESS_LIST = ( ADDRESS = ( P
+ROTOCOL = TCP)( PORT = 1521) ( HOST = oradb))) ( CONNECT_DATA = ( SER
+VICE_NAME = basetest)))
OK (90 msec)
$