b888 has asked for the wisdom of the Perl Monks concerning the following question:

Greetings all.

I'm trying to export some variables from module. While using filename same as package all seems ok.

file 'A.pm' 

package A;
use strict;
BEGIN {
  use Exporter();
  use vars qw(@EXPORT @ISA);
  @EXPORT = qw($var1);
  @ISA = qw(Exporter);
}
use vars @EXPORT;
$var1 = "1";

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file 'B.pl' 
#!/usr/bin/perl
package B;
use strict;
use A;
print "$var1\n";

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But when i'm trying to use package name that differs form filename, strict raises an error.

file 'A1.pm' 

package A;
...

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file 'B.pl' 

...
use A1;
...

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Is this perl problem, or i'm doing something wrong?

Replies are listed 'Best First'.
Re: exporting vars
by PodMaster (Abbot) on Nov 08, 2004 at 11:59 UTC
    Exporter exportes when import is called, and import is called when you use `perldoc -f use', `perldoc -f import', Tutorials.

    MJD says "you can't just make shit up and expect the computer to know what you mean, retardo!"
    I run a Win32 PPM repository for perl 5.6.x and 5.8.x -- I take requests (README).
    ** The third rule of perl club is a statement of fact: pod is sexy.

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Re: exporting vars
by Thelonius (Priest) on Nov 08, 2004 at 12:39 UTC
    This will work, if you really need to do this:
    BEGIN {require A1; import A;}

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Re: exporting vars
by fergal (Chaplain) on Nov 08, 2004 at 13:36 UTC
    When you do use A;, that includes a call to A->import but for A1 there is no import method so no variables are exported. One solution is to give A1 an import method - one that just redirects to A's import method. 
    package A1;

sub import
{
  A->export_to_level(1, @_);
}

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    export_to_level is a special routine provided by Exporter that allows you to control where the symbols will be exported to. The 1 here means export 1 level up. So it's saying "Hey A, don't export your symbols into my package (A1) export them into the package I was called from (B in your example)".

    A quick plug for one of my modules. Exporter::Easy lets you write 

    BEGIN {
  use Exporter();
  use vars qw(@EXPORT @ISA);
  @EXPORT = qw($var1);
  @ISA = qw(Exporter);
}
use vars @EXPORT;
$var1 = "1";

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    as 
    use Exporter::Easiest q( EXPORT => $var1 );
$var1 = "1";

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    it handles setting up all the other Exporter arrays too if you want it.
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