LISTENER.ORA

Below is an example of a typical Listener.ora file with one database instance registered.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = c:\oracle\product\11.2.0\dbhome_1)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:c:\oracle\product\11.2.0\dbhome_1\bin\oraclr11.dll")
    )
    (SID_DESC =
      (GLOBAL_DBNAME=orcl.sindre)
      (SID_NAME = orcl)
      (ORACLE_HOME = c:\oracle\product\11.2.0\dbhome_1)
    )	
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = sindre-2013)(PORT = 1521))
    )
  )

ADR_BASE_LISTENER = c:\oracle

Link to Oracle documentation