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How to declare global variables.

23 New Member

I am designing some code to communicate beetween two machines.
I want to declare variable (constants) into some seperate perl file and use them into all the perl scripts. I am confused how can I do this.
Do I need to create .pm file ? if yes please explain how can I create .pm file from .pl file.

Thanks in advance.
Oct 22 '07 #1
5 10118
971 Recognized Expert Contributor
perldoc -Constant

Oct 22 '07 #2
23 New Member
perldoc -Constant

I am not clear, how can I use some constant defined in some package in more then one perl script.

Also I am not clear how can I create a package with constant declaration.

Could you please expain it via some example.

Oct 22 '07 #3
4,059 Recognized Expert Specialist
Constants belong to the package they are defined in. To refer to a constant defined in another package, specify the full package name, as in Some::Package:: CONSTANT.
quoted from the CONSTANT manpage
Oct 22 '07 #4
23 New Member
quoted from the CONSTANT manpage
Still I am not confident enough to code this. Here is what I wanna do:

I have a perl file "lib.pl" and it contain:

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  2. use strict;
  3. our $somevariable = "It is Constant";
I have another perl file "test.pl"
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  2. use strict;
  3. my $x = $somevariable ; 
  4. print $x; # It should print It is Constant.
Please help me in getting the concept clear.

Oct 23 '07 #5
971 Recognized Expert Contributor
Here is one way you can do this.

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  1. package My::Config;
  2. use base Exporter; 
  4. our @EXPORT = qw(%config_vars);
  5. our @EXPORT_OK = qw(%config_vars);
  7. our %config_vars = (some_var    =>    'Hello',
  8.                     another_var =>     'World'
  9.                 );
  12. 1;
In your script add these two lines to your code to access the Config.pm file.
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  1. use lib '/path/to/file/lib/';
  2. use My::Config;
Then you can use $config_vars{'s ome_var'} and $config_vars{'a nother_var'} in your script where you want to.

Or you can use require. Which I showed an example in another thread.
Oct 23 '07 #6

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