Re: Data manipulation confusion

It helps to think about what you want to do.

If you find webserverX, you want to forget that you've seen serverX.
If you find serverX, you want to ignore it if you've seen webserverX.

Then coding becomes simple.

my %servers;
while (<>) {
   my ($server) = /^([^:]+):/ or next;
   delete($servers{$1}) if $server =~ /^web(.*)/;
   $servers{$server} = 1 if !$servers{"web$server"};
}

my @servers = keys(%servers);
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Re^2: Data manipulation confusion by hudsterboy (Initiate) on Mar 11, 2010 at 04:52 UTC
See, I would never have thought to look at it in those terms. My challenge is not so much to learn perl, but to change my way of thinking. If I hang around here, hopefully it will seep into my thick skull. Thank you so much. This worked perfectly.	[reply]
Re^3: Data manipulation confusion by ikegami (Patriarch) on Mar 11, 2010 at 05:35 UTC
I would never have thought to look at it in those terms. I'm not sure what terms you have picked. You didn't really describe what you wanted done. "I want this from that" requires guesswork to understand. Specifically, it doesn't answer what's special about the lines you want to keep. If you come up with a different answer to that question, you'll probably get a different program that gets the same result.	[reply]