Re: Implementing Mail::SRS in MIMEDefang

On Sun, 3 Oct 2004, Michael Faurot wrote:

> 
> In article <[email protected]> you wrote:
> 
> > The "die" statements are quite the standard way of doing things in Perl
> > modules. So this is actually really a Perl question.
> 
> I thought my difficulty might involve something like this as I haven't
> had much reason to use modules, until now.
> 
> > At any rate, you should enclose SRS calls in an 'eval' function, which will
> > return undef upon die. Like so:
> [...]
> > my $address;
> > if (eval {$address = $srs -> reverse ($to)}) {
> 
> This does indeed solve my difficulties.  Thanks!
> 
> Perhaps example code using eval could be incorporated into the POD
> documentation?  Presumably someone that does enough of this stuff, probably
> already knows that they should use eval, but for folks like me that are
> looking at the docs for example code just to get something working,
> would appreciate it. :)

Strictly speaking, you should inspect $@ and not rely on the returned 
value.

my $address = eval { $srs->reverse($to); };
unless ($@) {
  ...
}

However, if the code ever returns undef (which I don't think it can), that 
would also be an error, so your code is fine.

I will some examples in the documentation forthwith. Perhaps the code in
Daemon.pm offers the best examples.

S.

-- 
Shevek                                    http://www.anarres.org/
Robust Sender Policy Framework (SPF)      http://www.libspf2.org/
SRS for the next generation               http://www.libsrs2.org/