another way without making use of a module would be to define a hash or array with the values you wanted to find (I think I would use a hash)... If I noticed correctly all the lines you are intested in start with your 'key' and a colon so

%to_find = (
   'Set-Cookie' => '1',
   'Server'     => '1',
#etc so on and so forth
);

while (<$socket>) {
# split on the first colon, but leave the rest alone
   ($key,$rest) = split(/:/, $_, 2);
   print "$key: $rest\n" if ($to_find{$key});
}
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