>perl -le"package PkgA; my $foo = 'abc'; package PkgB; print $foo"
abc

##</code><code>##

my $stuff1;
my $stuff2 = undef;
my $stuff3 = undef;
my $stuff4 = undef;

$stuff1 = 'stuff1 stuff';
$stuff2 = 'stuff2 stuff';
$stuff3 = 'stuff3 stuff';
$stuff4 = 'stuff4 stuff';

print "stuff 1: $stuff1\n";
print "stuff 2: $stuff2\n";
print "stuff 3: $stuff3\n";
print "stuff 4: $stuff4\n";

##</code><code>##

my $stuff1 = 'stuff1 stuff';
my $stuff2 = 'stuff2 stuff';
my $stuff3 = 'stuff3 stuff';
my $stuff4 = 'stuff4 stuff';

print "stuff 1: $stuff1\n";
print "stuff 2: $stuff2\n";
print "stuff 3: $stuff3\n";
print "stuff 4: $stuff4\n";

##</code><code>##

my $stuff1;
my $stuff2;
my $stuff3;
BEGIN {
   $stuff1 = 'stuff1 stuff';
   $stuff2 = 'stuff2 stuff';
   $stuff3 = 'stuff3 stuff';
}

my $stuff4;
INIT {
   $stuff4 = 'stuff4 stuff';
}

print "stuff 1: $stuff1\n";
print "stuff 2: $stuff2\n";
print "stuff 3: $stuff3\n";
print "stuff 4: $stuff4\n";

##</code><code>##

my $stuff;
BEGIN {
   $stuff = undef;
   ...
   ...
   ...
   ...  Some complex code to initialize $stuff.
   ...
   ...
   ...
}

##</code><code>##

my $stuff;
BEGIN {
   ...
   ...
   ...
   ...  Some complex code to initialize $stuff.
   ...
   ...
   ...
}