[Brisbane-pm] Messing with Modules

[Martin Jacobs]

Hi folks,

Here I am again. This time I want to my main program (PERRMOSS) to  
execute a block of code in a separate folder (the reason is to give  
users a choice in doing a particular calculation).

What I did was straight out of 'Programming Perl', and it kind-of- 
works, though probably not as intended.

The block of code is in a file in a sub-folder as follows

input/Simple_Billycan_2_Stage.pm
		
And it is called in PERRMOSS at line 369 as follows;

use input::Simple_Billycan_2_Stage;

The reason that it is not at the top, after #!/usr/local/bin/perl ,  
is that PERRMOSS will not know which module to call until line 369.

Simple_Billycan_2_Stage.pm includes the following (this is not the  
final product, by the way);

package Simple_Billycan_2_Stage;
require	Exporter;
our @ISA = qw(Exporter);
our @Export = qw(camel);
our @Export_OK = qw(weight);
our $version = 1.00;

sub camel {print "One-hump dromedary\n"}

$weight = 1024;

1;

I understand that 'Exporter' should make 'camel' visible to PERRMOSS.

When I include the line...

Simple_Billycan_2_Stage::camel ();

It works as intended by printing One-hump dromedary to screen.

However, when I include the line...

camel();

I get the error message

Undefined subroutine &main::camel called at perrmoss.pl line 370,  
<RF> line 21.

Should I just be able to call 'camel' by camel(); ? Maybe I need to  
include the full 'path', though that seems rather messy.

What I am looking for is a way to reference a block of code that is  
outside the main program. I understand that modules are the way to  
go, but if there is a simpler way to do it, I would be glad to know  
about it.

Again, thanks for your help in advance.

Regards,
Martin
Visit my website...
http://web.mac.com/martin_jacobs1


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