CODEWITHSUNDEEP
perlnamespacesrequireperl-module
Jean
Jean

Reputation: 22675

Isolate namespaces in Perl script

I want to use a subroutine defined in a script B.pm(which I don't own) in my script A.pl. Since B.pm doesn't have a package pkg_B; header in it, all subroutines are imported when I add use B (); in A.pl. This results in Subroutine redefined warning when I try to run A.pl, since A.pl has a subroutine with the same name as that in B.pm. Is there a way I can isolate B.pm's namespace from A.pl without touching B.pm(since there are many other scripts blatantly consuming B.pm's subroutines without specifying scope)? My only solution seems to be renaming my subroutine, which I don't want to.

Upvotes: 1

Views: 171

Answers (1)

Steffen Ullrich
Steffen Ullrich

Reputation: 123260

... all subroutines are imported when I add use B (); in A.pl

The subroutines are not imported. They are defined in the namespace of your B.pm file. Since this file has no package name the namespace is main, i.e. the same namespace as A.pl is. And thus you have the conflict of two symbols with the name name inside the same namespace. What you could do is to include B.pm inside its own namespace, e.g.

{
     package Foo;
     do 'B.pm';  # defines sub foo
}

sub foo { ... }

foo(); # call local function
Foo::foo(); # call function from B.pm

Note that this is only a bad hack to work around bad code and you better should fix your code. And note also that you should not call your file/module B.pm/B because there is a core module with this name already.

Upvotes: 5

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