# File: Foo.pm

1;  # keep require happy

package Foo;

sub hello {
  print "Hello from Foo!\n";
}
__END__

##</code><code>##

# File: foo.pl
require Foo;

sub hello {
  print "Hello from main!\n";
}

hello();        # prints "Hello from main!\n";
main::hello();  # prints "Hello from main!\n";
::hello();      # prints "Hello from main!\n";
Foo::hello();   # prints "Hello from Foo!\n";
__END__

##</code><code>##

# File: Foo.pm

1;  # keep require happy

package Foo;

sub hello {
  print "Hello from Foo!\n";
}

package Foo_Helper;

sub hello {
  print "Hello from Foo_Helper!\n";
}
__END__

##</code><code>##

# File: foo.pl
require Foo;

sub hello {
  print "Hello from main!\n";
}

hello();              # prints "Hello from main!\n";
Foo::hello();         # prints "Hello from Foo!\n";
Foo_Helper::hello();  # prints "Hello from Foo_Helper!\n";
__END__

##</code><code>##

require Foo_Helper;

##</code><code>##

Can't locate Foo_Helper.pm in @INC (@INC contains: /usr/local/lib/perl/5.8.4 /usr/local/share/perl/5.8.4 /usr/lib/perl5 /usr/share/perl5 /usr/local/lib/site_perl .) at foo.pl line 2.

##</code><code>##

# File: Foo.pm

1;  # keep require happy

package Foo_Helper;

sub hello {
  print "Hello from Foo_Helper!\n";
}

package Bar;

sub hello {
  print "Hello from Bar!\n";
}

# Look, Ma!  No Foo!
__END__

##</code><code>##

# File: foo.pl
require Foo;

sub hello {
  print "Hello from main!\n";
}

hello();              # prints "Hello from main!\n";
Bar::hello();         # prints "Hello from Bar!\n";
Foo_Helper::hello();  # prints "Hello from Foo_Helper!\n";
__END__

##</code><code>##

# File: Foo.pm

1;  # keep require happy

package Foo;

sub hello {
  print "Hello from Foo!\n";
}

__END__

##</code><code>##

# File: More_Foo.pm

1;  # keep require happy

package Foo;

sub hello_2 {
  print "Still in Foo!\n";
}

__END__

##</code><code>##

# File: foo.pl

require Foo;
require More_Foo;

sub hello {
  print "Hello from main!\n";
}

hello();              # prints "Hello from main!\n";
Foo::hello();         # prints "Hello from Foo!\n";
Foo::hello_2();       # prints "Still in Foo!\n";

__END__

##</code><code>##

require Foo;
require More_Foo;

##</code><code>##

Undefined subroutine &Foo::hello_2 called at foo.pl line 10.

##</code><code>##

# File: Foo.pm

require More_Foo;

1;  # keep require happy

package Foo;

sub hello {
  print "Hello from Foo!\n";
}