#!/usr/bin/perl -w

package Szywiecki;

$Robert = "the boss";

sub terminate {
  my $name = shift;
  # the following line was updated on 2004-12-29 following on aristotle73's comment
  print "$Robert has canned ${name}'s sorry butt\n";
}

terminate("arturo"); # prints "the boss has canned arturo's sorry butt"

package main;

# terminate("arturo"); # produces an error if you uncomment it

##</code><code>##

#!/usr/bin/perl -w

use strict;

$Robert = "the boss";  # error!
print "\$Robert = $Robert\n";

##</code><code>##

#!/usr/bin/perl -w

use strict;

$main::Robert = "the boss";
print "\$main::Robert = $main::Robert\n";

##</code><code>##

#!/usr/bin/perl -w

package Szyewicki;

$Robert = "the boss";

package PoolHall;

$Robert = "the darts expert";

package Sywiecki; # back to work!

print "Here at work, 'Robert' is $Robert, but over at the pool hall, 'Robert'
is $PoolHall::Robert\n";

##</code><code>##

#!/usr/bin/perl -w

use strict;

#remember we're in package main

use vars qw($foo);

$foo = "Yo!"; # sets $main::foo

print "\$foo: $foo\n"; # prints "Yo!"

my $foo = "Hey!"; # this is a file-level my variable!

print "\$foo: $foo\n"; # prints "Hey!" -- new declaration 'masks' the old one

{ # start a block
  my $foo = "Yacht-Z";
  print "\$foo: $foo\n"; 
  # prints "Yacht-Z" -- we have a new $foo in scope.
  print "\$main::foo: $main::foo\n"; 
  # we can still 'see' $main::foo
  subroutine();
} # end that block

print "\$foo: $foo\n"; # there it is, our file-level $foo is visible again!

print "\$main::foo: $main::foo\n"; # whew!  $main::foo is still there!

sub subroutine {
  print "\$foo: $foo\n"; # prints "Hey!" -- as the script is written
  # why?  Because the variable declared in the naked block
  # is no longer in scope -- we have a new set of braces.
  # but the file-level variable is still in scope, and
  # still 'masks' the declaration of $main::foo
}

package Bar;

print "\$foo: $foo\n"; # prints "Hey!" -- the my variable's still in scope
# if we hadn't made that declaration above, this would be an error: the
# interpreter would tell us that Bar::foo has not been defined.

##</code><code>##

#~/usr/bin/perl -w

use strict;

our ($bob);
use vars qw($carol);
$carol = "ted";
$bob = "alice";

print "Bob => $bob, Carol => $carol\n";

package Movie;

print "Bob => $bob, Carol => $carol\n";

##</code><code>##

#!/usr/bin/perl -w

use strict;

use vars qw ($foo); # or "our $foo" if you're using 5.6

$foo = "global value";

print "\$foo: $foo\n"; # prints "global value"

print "mysub  result '", &mysub(), "'\n"; #"global value"
print "localsub result '", &localsub(), "'\n"; # "local value"
print "no sub result '",&showfoo(), "'\n"; #"global value"

sub mysub {
 my $foo = "my value";
 showfoo(); # 
}

sub localsub {
 local $foo = "local value";
 showfoo(); # ALWAYS prints "local value"
}

sub showfoo {
 return $foo;
}