Recovery

     If a system failure interrupts your editing session, you can usually
     recover your work.  TPU makes this recovery possible by allowing you
     to record the keystrokes of your editing session in a keystroke journal
     file, or changes made to buffers in buffer change journal files.  You
     can recover edits from your entire editing session by recovering from a
     keystroke journal file, or you can recover changes made to specific
     buffers by recovering from one or more buffer change journal files.

     o  By default, TPU does not journal.  The application layered on
        TPU is responsible for processing the /JOURNAL qualifier.

     o  In EVE, if you do not specify this qualifier, EVE does only buffer
        change journaling.  With this qualifier followed by a file name, EVE
        does both buffer change and keystroke journaling.  By default, the
        keystroke journal file is created in your current, default
        directory, with the file type .TJL.

     o  To give the keystroke journal file a different name or directory,
        when you invoke EVE, use the /JOURNAL= and specify the journal file
        you want.

     o  If you do not want any journaling, use /NOJOURNAL.

     o  To turn on keystroke journaling during an editing session (either
        because journaling was never started or was started and then turned
        off), use the JOURNAL_OPEN built-in.  To stop keystroke journaling
        during an editing session, use the JOURNAL_CLOSE built-in.

     o  To turn buffer change journaling on or off during an editing session
        use the SET (JOURNALING) built-in.  You can also use the SET
        (JOURNALING) built-in to adjust the journaling frequency.

     o  Normally, the journal file is deleted automatically when you exit or
        quit.  However, if the system fails during your editing session, the
        journal file is saved.

     To recover your edits from a journal file after a system failure,
     reissue the DCL command you used for that editing session (including
     all qualifiers) -- and adding the /RECOVER qualifier.  For example, if
     the system failed when you were editing a file called JABBER.TXT, you
     type the following DCL command:

        $ EDIT/TPU jabber.txt/RECOVER

     Note that for keystroke recovery to work, terminal characteristics must
     be the same as they were when you started the editing session.  Also,
     all input files must be in the same state as at the start of the
     editing session.

     When you invoke TPU with the /RECOVER qualifier, TPU runs the
     journal file and recovers the edits you made up to the point where the
     system failed.  (The last few keystrokes or operations may be lost.)
     You can then resume the editing session.  Any new edits are journaled.
     Recovering from a buffer change journal file recovers only the changes
     made to that buffer.

     The recovery may not work (or may not be accurate) if the original
     editing session included any of the following operations because they
     do not necessarily behave the same the second time they are performed:

         o  A CTRL/C sequence

         o  A CTRL/T sequence

         o  Cut and paste operation from a file accessed in a subprocess

         o  Cut and paste operation from a mail message

         o  An operation using the contents of the message buffer

         o  An operation involving the CALL_USER built-in

         o  An operation using the date or time from the FAO built-in

     It may be possible to edit a journal file, but VSI does not
     recommend this because you may alter or delete information necessary
     for the recovery to work.

     For more information, see DCL HELP on EDIT/TPU/JOURNAL and /RECOVER.

     Related topics

     JOURNAL_CLOSE   JOURNAL_OPEN   SET(JOURNALING)