[Date Prev] [Date Next] [Thread Prev] [Thread Next] Date Index Thread Index Search archive:
Date:Thu, 8 Jul 2004 11:11:58 +0000 (UTC) 
Subject:Re: Ved Backup Directory 
From:Aaron Sloman 
Volume-ID: 


John Duncan <agley@optusnet.com.au> writes:

>     Does anyone know a way to set a separate directory for
> the backup files that Ved creates ?

Ved has two backup mechanisms. An old one that merely counts changes
per file and can be disastrous if you make a few changes to a lot of
files and then the system crashes. That one uses vedautowrite.

There is a newer one, ved_autosave, that allows you to specify a
time delay between writes. There's a version in the core poplog
system (with help file dated 1991) and a newer one from Birmingham
with help file last revised around Nov 1995, which should be
included in the packaged linux poplog systems. Alternatively
it can be fetched here in two files:

    http://www.cs.bham.ac.uk/research/poplog/auto/ved_autosave.p
    http://www.cs.bham.ac.uk/research/poplog/help/ved_autosave

there's information in the help file about various options
including:

-   If vedautosave_preserve is a string that names a directory then the
    first time any file is saved in a particular Poplog session the
    current version on disk is copied to that directory. If necessary
    the usual Poplog backup version will be created for the copied file.
    (I.e. the extra backups are themselves backed up.)

-   If it is a string but not a directory (e.g. '.bak', or '~~') then
    the first time any file is saved in a particular Poplog session the
    current version on disk is copied to a file with the same pathname,
    but with that string appended. If that suffix was used in a previous
    session then the usual Poplog backup version will be created for
    that file (with "-" appended on UNIX).

I don't know if anyone has ever used those options for modifying how
files are backed up, but I have not tested them for many years, so
they may be broken!

Also you can get nasty surprises if you start ved, do some work on a
file, then leave ved completely, then restart it, and then find that
the oldest backed up version is the one produced at the end of the
first session, whereas you wanted an older version. One answer is to
change the backup directory to reflect the date and time when lib
autosave is compiled (e.g. in your vedinit.p), but I have not tried
that.

Aaron
====
Aaron Sloman, ( http://www.cs.bham.ac.uk/~axs/ )
JOBS AVAILABLE: http://www.cs.bham.ac.uk/research/projects/cosy/
PAPERS: http://www.cs.bham.ac.uk/research/cogaff/  (also talks in /talks )
FREE BOOK: http://www.cs.bham.ac.uk/research/cogaff/crp/
FREE TOOLS: http://www.cs.bham.ac.uk/research/poplog/packages/simagent.html