The RENAME_FILE procedure renames a file.

  Syntax:

     RENAME_FILE( old-file-name, new-file-name [, error-return] )

  The parameter 'old-file-name' specifies the names of one or more
  files  whose  specifications  are  to be changed.  The parameter
  'new-file-name'  provides  the  new  file  specification  to  be
  applied.    The   'error-return'  parameter  contains  an  error
  recovery code if specified.