baxy77bax has asked for the wisdom of the Perl Monks concerning the following question:

hi,

i'm having some trouble with writing a module. i'm working under win32 and i would like to create a module. actually, just pass some subroutines into a module for organizing purposes. example: 


"Test.pl" 

#use lib "./Nzd/";  ->not sure if this should be here
#push @INC, "./Nzd/"; ->not sure if this should be here
use strict;
use warnings;

use Nzd::NZD;   #Nzd is a directory containing NZD.pm

my ($x,$y)= (8,36);

my $t=NZD($x,$y);
my $c=$x/$t;
my $g=$y/$t;

print "\nc= $c,  g= $g";


------------------------------------

"NZD.pm"

package Nzd::NZD;

use strict;
sub NZD {
  my ($x, $b) = @_;
   if ($x > $b){
       ($x,$b) = ($b,$x);
  }
  while ($x) {
    ($x, $b) = ($b % $x, $x);
  }
  return $b;
}
1;

[download]
as i tried to show i have 2 scripts *.pl and *.pm and from Test.pl i would like to call a sub NZD which is situated in NZD.pm, that is in a ./Nzd directory. and obviously i don't know how to do it. message i'm getting is that i didn't define the NZD sub

"Undefined subroutine &main::NZD called at Test.pl line 10."

where is the problem ?

i'm doing wrong...

thanks for all your help

Replies are listed 'Best First'.
Re: how to write a module
by toolic (Bishop) on Jun 13, 2008 at 17:29 UTC
[reply]
      i tried exactly the same example as the tutorial states and i'm receiving the same message:

      use strict;

# you may need to set @INC here (see below)

my @list = qw (J u s t ~ A n o t h e r ~ P e r l ~ H a c k e r !);

#case 1
 use MyModule;
 print func1(@list),"\n";
 print func2(@list),"\n";

# case 2
# use MyModule qw(&func1);
# print func1(@list),"\n";
# print MyModule::func2(@list),"\n";

# case 3
# use MyModule qw(:DEFAULT);
# print func1(@list),"\n";
# print func2(@list),"\n";

# case 4
# use MyModule qw(:Both);
# print func1(@list),"\n";
# print func2(@list),"\n";

-------------------------------------

package MyModule;

use strict;
use Exporter;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);

$VERSION     = 1.00;
@ISA         = qw(Exporter);
@EXPORT      = ();
@EXPORT_OK   = qw(func1 func2);
%EXPORT_TAGS = ( DEFAULT => [qw(&func1)],
                 Both    => [qw(&func1 &func2)]);

sub func1  { return reverse @_  }
sub func2  { return map{ uc }@_ }

1;

      [download]
      could it be because i'm on win32, or i'm just too tiered to see the obvious?
[reply]
[d/l]
        Case 1 doesn't work because @EXPORT is empty. The symbols in @EXPORT_OK are available for importing but they are not automatically imported.
[reply]
[d/l]
[select]
        The tutorial states that Case 1 will generate errors:
        Case 1: Because our module exports nothing by default we get errors...

        When I run Case 1, I get this error, as expected: 

        Undefined subroutine &main::func1 called at ...

        [download]

        Case 3 will also generate an error; Cases 2 and 4 should work properly.

[reply]
[d/l]
Re: how to write a module
by pc88mxer (Vicar) on Jun 13, 2008 at 17:24 UTC
[reply]
[d/l]
[select]
Re: how to write a module
by sasdrtx (Friar) on Jun 13, 2008 at 17:26 UTC
    You need to either export 'NZD' from NZD.pm, or Test.pl must use its fully-qualified name. See perlmod for more information.

    btw, NZD.pm is a module, not a script.

    Update: btw2: You have 3 different NZDs, which could be confusing. Make them different if you can.


    sas
[reply]
Re: how to write a module
by Zen (Deacon) on Jun 13, 2008 at 18:32 UTC
    ----------------
    "Test.pl"

    use lib './Nzd';
    use NZD;
    ----------------
    "NZD.pm"

    package NZD;
[reply]

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