Services & Resources / Wolfram Forums
MathGroup Archive
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Clean-up code for packages

  • To: mathgroup at
  • Subject: [mg74974] Re: Clean-up code for packages
  • From: "Szabolcs" <szhorvat at>
  • Date: Fri, 13 Apr 2007 02:03:55 -0400 (EDT)
  • References: <evht7d$2lv$><evksuq$rs0$>

On Apr 12, 11:08 am, Albert <awnl at> wrote:
> Hi,
> > Is there a way for packages to set up some clean-up code that is
> > executed before Quit[]? (e.g. delete temporary files that may have
> > been created by package functions)
> I don't know if there is a better way to do this than to manipulate
> $Epilog...
> > I found $Epilog, but I cannot figure out how to prepend commands to it
> > if it is already defined. E.g. the default value of $Epilog is
> > $Epilog := <<end`
> > and I'd like to modify it to be
> > $Epilog := (someCommand[];<<end`)
> > without knowing the its initial value.
> > Is there a way to do this safely? Or is there any other way to run the
> > clean-up code when the session is terminated?
> ... but this is one way to alter $Epilog, I hope it will be "save
> enough" for your needs. You need to look up the OwnValues directly to
> get ahold of the unevaluated code and then take some care to not
> evaluate it too early:
> SetDelayed @@@ Cases[
>    OwnValues[$Epilog],
>    HoldPattern[RuleDelayed[Verbatim[HoldPattern][$Epilog], origcode_]] :>
>      Hold[$Epilog, CompoundExpression[myCommand[], origcode]]
> ]
> (* test it: *)
> myCommand[] := Print["Hello!"];
> Quit[]
> Of course there are other ways to extract the origcode, when testing you
> might look at OwnValues[$Epilog] before and after evaluating the above
> expression...
> hth,
> albert

Thanks for your reply! The missing piece that I needed was
OwnValues[]. I found DownValues[], but OwnValues[] is missing from
both the Built-in Functions section and the Master Index in the Help

  • Prev by Date: Re: Variable containing code
  • Next by Date: RE: Variable containing code
  • Previous by thread: Re: Re: Clean-up code for packages
  • Next by thread: Beginner--Help on Listing Values