c:\@Work\Perl\monks\R0b0t1>perl -le
"package Blah; {
     sub foo {
         print \"bar!\n\";
     }
 }
 package main; {
     foo();
 }
"
Undefined subroutine &main::foo called at -e line 1.

c:\@Work\Perl\monks\R0b0t1>perl -le
"package Blah; {
     sub foo {
         print \"bar!\n\";
     }
 }
 package main; {
     Blah::foo();
 }
"
bar!