You have not imported hello into script.pl. Change your use statement to:

use Foo qw/hello/;
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and try again. See Exporter for examples.

Yes I forgot to import the "hello" sub. Done that, I still can not print the variable "$hello" in the module, not in the script.


Use of uninitialized value $hello in print at Foo.pm
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Indeed. Your module says:

my $hello = hello();

sub hello {

    my $h = shift;
    return;

}

print $hello;
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So $hello is given the return value of hello() which is undef. You probably want to return $h instead.

PS. I would strongly advise naming your variables and your subroutines with different names, otherwise it's going to get very confusing very quickly.

PPS. and as stevieb quite rightly says, pass an argument when you call hello().

Well, when you initialize the module by loading it, this executes:

my $hello = hello();
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Then later, you try to print $hello. It's going to be uninitialized, because you're not sending a value into hello() in that call. Try: my $hello = hello('blah');

Hello Anonymous Monk,

See sample bellow:

#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';

=alternative
BEGIN {
    push ( @INC,"/your/dir/path");
}
=cut

use lib qw(/your/dir/path);
use Foo::Bar qw(hello echoTest); # update adding echoTest

say hello();
say echoTest('Expecting Echo!'); # update adding echoTest subroutine

__DATA__

$ perl test.pl
Hello!
Expecting Echo! # update adding echoTest stdout
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Sample of the module, in my dir /my/dir/script I have my module Foo::Bar or Foo/Bar.pm.:

package Foo::Bar;

use strict;
use warnings;
use Exporter qw(import);

our @EXPORT_OK = qw(hello echoTest); # update adding echoTest

sub hello {
    return 'Hello!';
}

# update adding echoTest sub

sub echoTest {
    return shift;
}

1;
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Update: I just noticed that you are wondering how you pass a value to the module. I have updated the code by adding a new subroutine that returns the input string. I hope this is what you are looking for. If not update your question so we can provide more information.

Hope this helps, BR.

Deluxe edition:

Please see Class::Tiny for further variations.

Update: Fixed link to wrong module.

Update 2: A fellow monk asked for some more flexibility:

Best regards, Karl