This demonstrates the general flow of the thing using recursion. If your pages have a lot of links, you could blow perls runtime stack. 

#! perl -slw
use strict;

sub getHTML{
    my $url=shift;
    #! Replace with the code to get HTML for $url
    return join' : ',
        map{
            local $"=''; #!"
            "www.@{[ chr(97+rand 26), int rand 10 ]}.com"
        } 0 .. rand 5;
}

sub getLinks{
    my ($webref, $url) = @_;
    $webref->{$url}{html} = getHTML $url;

    #! Replace with code to extract links from html
    my @links =    split' : ', $webref->{$url}{html};

    return @links;
}

sub spider {
    my ($webref, $url) = @_;
    my @links = getLinks $webref, $url;
    for my $link (@links) {
        next if exists $webref->{$link};
        spider( $webref, $link );
    }
}

my %web;

spider \%web, 'First.com';

for my $url (sort keys %web) {
    print "$url => $web{$url}{html}";
}

[download]

Okay you lot, get your wings on the left, halos on the right. It's one size fits all, and "No!", you can't have a different color.
Pick up your cloud down the end and "Yes" if you get allocated a grey one they are a bit damp under foot, but someone has to get them.
Get used to the wings fast cos its an 8 hour day...unless the Govenor calls for a cyclone or hurricane, in which case 16 hour shifts are mandatory.
Just be grateful that you arrived just as the tornado season finished. Them buggers are real work.

In reply to Re: Creating loop on undefined hash key value by BrowserUk
in thread Creating loop on undefined hash key value by S_Shrum

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