Re: [MacPerl] Problem w/making runtime version of script

[Ronald J Kimball <rjk@linguist.dartmouth.edu>]

On Mon, Aug 09, 1999 at 06:18:32PM -0700, Bruce Van Allen wrote:
> At 10:42 AM -0600 8/9/99, Brenda Cannon wrote:
> >I have the following snippet of code at the beginning of one of my
> >scripts:
> >
> >#!/usr/local/bin/perl -w
> >#use strict
> >
> >use constant FALSE => 0;
> >use constant TRUE => 1;
> >
> >use Getopt::Long;
> >use Config;
> >
> >require "shellwords.pl";
> >require "GUSI.ph";
> >
> >
> >The problem is that when I actually tried making a runtime version of
> >this script it saved it with no errors/warnings, but then when I
> >actually try to run it on the other machine I get the error that it
> >cannot locate constant.pm in @INC.  Can anyone tell me what is going on
> >here?
> 
> The statement
> 
> 	use constant whatever
> 
> is not Perl.  :-)
> 
> As the Camel says: "The use declaration imports some semantics into 
> the current package from the named module..."
> 
> So Perl expects a module named 'constant' (constant.pm, really). You 
> got no warnings because it's plausible that there would be such a 
> module. Only when the script executes would it actually not find the 
> module constant.pm.

Maybe your installation of Perl won't find the constant.pm module, but mine
certainly will.

MacPerl:lib:constant.pm


> What can be confusing here is that there is a Perl Standard Library 
> module called 'vars' whose purpose is to pre-declare names for global 
> variables, so you see statements like
> 
> 	use vars '$a', '@blah', '%doodah';    # OK.
> 	use vars qw($a @blah %doodah);        # Same, easier to type.
> 
> Because it's part of the Standard Library, it's in virtually every 
> Perl installation.

constant.pm is also part of the standard library, and is in virtually every
Perl installation.


> On a related topic: it looks like what you're doing is setting true & 
> false variables or constants, and that's not the way it works in Perl 
> either ... :-)

That's true.  Setting constants for TRUE and FALSE is just silly.


Ronald

===== Want to unsubscribe from this list?
===== Send mail with body "unsubscribe" to macperl-request@macperl.org