To follow up to BrowserUk's suggestion, you could also use a '%seen' hash (there's nothing magical about the name - it's just an indicator of its function.) This also processes the URLs in order. 

my %seen;
for $urls (@hrefs){  
    next if $seen{$urls}++;
    my $query = $res->query($urls, "A"); 
    ...

[download]

Each new URL becomes a key in '%seen'; if a key identical to the current one already exists, we return to the top of the loop. 


-- 
Human history becomes more and more a race between education and catastrophe. -- HG Wells

In reply to Re: issues maintaining uniqueness by oko1
in thread issues maintaining uniqueness by jkstraw

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