VMS Help PASCAL, Input Output, General, OPEN  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The OPEN procedure opens a file and allows you to  specify  file
  characteristics.

  Syntax:

            OPEN( file_variable
                  ,[[file_name]]
                  ,[[history]]
                  ,[[record_length]]
                  ,[[access_method]]
                  ,[[record_type]]
                  ,[[carriage_control]]
                  ,[[organization]]
                  ,[[disposition]]
                  ,[[file_sharing]]
                  ,[[user_action]]
                  ,[[default_file_name]]
                  ,[[ERROR := error_recovery]] )

            OPEN( FILE_VARIABLE     := file_variable
               [[,FILE_NAME         := file_name]]
               [[,HISTORY           := history]]
               [[,RECORD_LENGTH     := record_length]]
               [[,ACCESS_METHOD     := access_method]]
               [[,RECORD_TYPE       := record_type]]
               [[,CARRIAGE_CONTROL  := carriage_control]]
               [[,ORGANIZATION      := organization]]
               [[,DISPOSITION       := disposition]]
               [[,SHARING           := file_sharing]]
               [[,USER_ACTION       := user_action]]
               [[,DEFAULT           := default_file_name]]
               [[,ERROR             := error_recovery]] )

  Before the OPEN procedure is called, the file  is  in  undefined
  mode; its mode does not change after OPEN has been executed.

  You cannot use OPEN on a file variable that is already open.

  If you use INPUT, OUTPUT, or ERR, Compaq Pascal implicitly opens
  them  just  before  their  first  use.  Compaq Pascal implicitly
  opens INPUT with a history of READONLY.  If you choose, you  can
  explicitly open INPUT, OUTPUT, or ERR; to do this, call the OPEN
  procedure at any point in your compilation unit before  you  use
  the first I/O routine on that file.

  Because the RESET, REWRITE,  and  EXTEND  procedures  implicitly
  open  files, you need not always use the OPEN procedure.  RESET,
  REWRITE, and EXTEND impose the same  defaults  as  OPEN,  except
  where noted (in the HISTORY parameter).

  You must use the OPEN procedure  to  create  a  TEXT  file  with
  fixed-length  components,  to  create  a  file  with relative or
  indexed organization, to open a file for direct or keyed access,
  or to specify a line length other than the default for a line in
  a TEXT file.

  See the  "Compaq  Pascal  Language  Reference  Manual"  for  the
  complete description of the OPEN procedure.

  Additional Information (explode) :

• File Variable
• File Name
• History
• Record Length
• Access Method
• Record Type
• Carriage Control
• Organization
• Disposition
• Sharing
• User Action
• Default
• Error Recovery