#!perl -w
use strict; # ALWAYS!

a("what"); 
b("the"); 

{
   use vars ('$var');
   local $var; # shared only between a() and somesub()
   sub a { local $var = shift; _somesub() }
   sub b { local $var = shift; _somesub() }

   # sub routines with a leading _ usually denotes a private func.
   sub _somesub { print $var,  $/ }
}