... 
  my $conn = "dbi:Oracle:HOST=$host;SID=$sid;port=1521"; 
   my $db_h = DBI->connect ( $conn, 
                             $user, 
                             $pwd, 
                             { 
                                 AutoCommit => 0, # 0 = false 
                                 RaiseError => 0, 
                                 PrintError => 0, 
                                 ChopBlanks => 1  # CHAR chopped 
                             } 
                           ) || BEGIN { print color 'red on_black'; 
                                        warn "\n" . "x" x 70 . "\n" . 
                                             "\t--> Connecting to " . 
                                             uc ( $sid ) . " as " . 
                                             uc ( $user ) . " <--\n\n" 
. 
                                             $DBI::errstr . 
                                             "\n" . "x" x 70 . "\n"; 
                                        print color 'reset'; 
                                        print "\n"; 
                                        return undef; 
                                      }; 
... 

##</code><code>##

*********************************************************************** 
Fatal NI connect error 12541, connecting to: 

(DESCRIPTION=(ADDRESS=(HOST=machineA.com)(PROTOCOL=tcp)(PORT=1521))(CONNECT­_DATA=(SID=aaa)(CID=(PROGRAM=t2.pl@bbb) 
(HOST=aaa)(USER=uuuuu)))) 

*********************************************************************** 
Fatal NI connect error 12535, connecting to: 

(DESCRIPTION=(ADDRESS=(HOST=machineA.com)(PROTOCOL=tcp)(PORT=1521))(CONNECT­_DATA=(SID=aaa)(CID=(PROGRAM=t2.pl@bbb) 
(HOST=aaa)(USER=uuuuu)))) 

*********************************************************************** 
Fatal NI connect error 12505, connecting to: 

(DESCRIPTION=(ADDRESS=(HOST=machineA.com)(PROTOCOL=tcp)(PORT=1521))(CONNECT­_DATA=(SID=aaa)(CID=(PROGRAM=t2.pl@bbb) 
(HOST=aaa)(USER=uuuuu))))