Cross Platform Perl

[rickm at isite.net.au]

Doh! Should have checked mail again before replying. Paul's solution is better 
than mine :)


Quoting Paul Fenwick <pjf at perltraining.com.au>:

> G'day Everyone,
> 
> 	Rob and Adam are indeed correct.  You do need a string
> eval and not a block eval.  My mistake.  :)
> 
> 	Cheers,
> 
> 		Paul
> 
> On Thu, Oct 17, 2002 at 01:27:37PM +1000, Rob Casey wrote:
> > Just a follow up to this ...
> > 
> > > BEGIN {		# So we run at the same time as most use
> > statements.
> > > 	if ($^O eq 'MSWin32') {
> > > 		eval { use My::Module; }
> > > 	}
> > > }
> > 
> > This will fail - As the compiler will find this use statement and
> > attempt to include the module at this point.  To make use of dynamic
> > loading of modules, the eval statement must called with a string
> > argument as this string is not interpreted at compile time, but at the
> > time of execution.
> > 
> > Regards,
> > Rob
> > 
> > 
> > Rob Casey
> > Business Manager, Senior IT Consultant
> > Cowsnet Internet and Professional Services
> > http://www.cowsnet.com.au
> > 
> >  
> > 
> > -----Original Message-----
> > From: owner-melbourne-pm at pm.org [mailto:owner-melbourne-pm at pm.org] On
> > Behalf Of Paul Fenwick
> > Sent: Thursday, 17 October 2002 1:02 PM
> > To: Adam Clarke
> > Cc: melbourne-pm at pm.org
> > Subject: Re: Cross Platform Perl
> > 
> > 
> > G'day Adam,
> > 
> > On Thu, Oct 17, 2002 at 12:42:42PM +1000, Adam Clarke wrote:
> > 
> > > I'm trying to write a script that runs on Linux (Unix) and Win32. I
> > want 
> > > to /use/ a module when on Win32 (to access the registry) that doesn't 
> > > exist in Unixy perl. Is there a way to skip a use statement at runtime
> > 
> > > based on platform or is the only/best way to make a full build 
> > > (MakeMaker thing) and handle the differences there somehow. If the 
> > > latter, anyone got some simple pointers.
> > 
> > Glad you asked!  Perl has a variable called $^O (or $OSNAME when
> > using English) that gives you the name of the operating system
> > you're running under.
> > 
> > So you can do the following:
> > 
> > BEGIN {		# So we run at the same time as most use statements.
> > 	if ($^O eq 'MSWin32') {
> > 		eval { use My::Module; }
> > 	}
> > }
> > 
> > The eval is needed because usually use statements get executed
> > immediately, regardless of context.  The BEGIN means that your
> > chunk of code is executed "at compile time".  If this isn't important,
> > you can leave the BEGIN block out.
> > 
> > There's lots of code out there which does different things depending
> > upon the OS.  Take a look at File::Copy's source code
> > (perldoc -m File::Copy) to see a lot of this in action.
> > 
> > Cheers,
> > 
> > 	Paul
> > 
> > -- 
> > Paul Fenwick <pjf at perltraining.com.au> | http://perltraining.com.au/
> > Director of Training                   | Ph:  +61 3 9354 6001
> > Perl Training Australia                | Fax: +61 3 9354 2681
> > 
> 
> 
> 
> -- 
> Paul Fenwick <pjf at perltraining.com.au> | http://perltraining.com.au/
> Director of Training                   | Ph:  +61 3 9354 6001
> Perl Training Australia                | Fax: +61 3 9354 2681