problem ..related to perl package concept

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

i am writing a script like this

#! /usr/bin/perl

 $var='one';
 mypackage::var='two';

 sub mypackage::func(){
  print "my \$var is $var";
}
 mypackage:: func();
[download]

i want to print the value from my package but not from main but it is not working can anyone explain why ... i have seen in perlmod that we define a sub in a different package if we explicitly declare its name with the package we intend to keep it in. OUTPUT

csbu061 mhalder 125: perl test2.pl Can't modify constant item in scalar assignment at test2.pl line 6, near "'two';" Execution of test2.pl aborted due to compilation errors.

Comment on problem ..related to perl package concept Download Code

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Re: problem ..related to perl package concept by jasonk (Parson) on Dec 09, 2008 at 04:36 UTC
It doesn't really have anything to do with packages, it comes down to the difference between `$var` and `var`. You need a `$` on the second one too... www.jasonkohles.com We're not surrounded, we're in a target-rich environment!	[reply] [d/l] [select]
Re: problem ..related to perl package concept by moritz (Cardinal) on Dec 09, 2008 at 07:44 UTC
can anyone explain why You're putting a sub into a different package, but you're not in that package. If you want that, use something like this: `#!/usr/bin/perl -w $var='one'; $mypackage::var='two'; { package mypackage; sub func { print "my \$var is $var\n"; } } mypackage::func(); __END__ Name "main::var" used only once: possible typo at foo.pl line 3. my $var is two` [download]	[reply] [d/l]
Re: problem ..related to perl package concept by Bloodnok (Vicar) on Dec 09, 2008 at 09:07 UTC
Errrm, if you'd `use`d strictures, they might just have spotted that `mypackage::var='two';` is in error - you forgot to prefix the var name with the var type e.g. `$mypackage::var='two';`... A user level that continues to overstate my experience :-))	[reply] [d/l] [select]
Re: problem ..related to perl package concept by kyle (Abbot) on Dec 09, 2008 at 15:51 UTC
You don't need to put the sub in the other package in order to access that package's variables. Just refer to them explicitly, as you do in the assignment. `$var = 'one'; $mypackage::var = 'two'; sub we_got_the_func { print "Other \$var is $mypackage::var\n"; } we_got_the_func(); __END__ Other $var is 'two'` [download]	[reply] [d/l]