What does "use vars '@ISA';@ISA = 'LWP::UserAgent';my $agent = __PACKAGE__->new;"

[Siegfried Heintze]

Can someone help me understand Lincoln Stein's code I found in his book on
network programming with perl? This is the beginning of a screen scraper. I
thought ISA was an array of ancestors used exclusively for defining
descendant classes. I guess I'm wrong. 

 

What the heck is going on here? I understand the "use" statements, but the
subsequent statements baffle me.

 

Thanks,

Siegfried

 

 

use LWP;

use PromptUtil;

use HTTP::Cookies;

use HTML::Parser;

use URI;

 

use vars '@ISA';

@ISA = 'LWP::UserAgent';

 

my $agent    = __PACKAGE__->new;