http://www.perlmonks.org?node_id=58797


in reply to Better way?

This looks like a perl based rsync(1) kind of thing.
Unless I'm horribly wrong here, this is really not that ugly. About the only thing ugly is the memory usage for the various lists. That could get big, if the file lists are long. Yours is pretty easily understood code, and unless it runs many many times a second, should not be a huge problem. But if you wanted to trim up the memory usage, perhaps looking at processing the lists sequentially, and storing only exceptions would be better/faster/more elegant.
# assuming %existing_files is a hash of existing # filenames and descriptions # and we recieve the new list of files on stdin while (<STDIN>) { chomp; if ($existing_files{$_}) { delete $existing_files{$_}; } else { $existing_files{$}="Newly Added file $_"; } } # at this point %existing_files contains the files that # should be deleted, and the newly added ones, # with the description used to differentiate them foreach (sort keys %existing_files} { if ($existing{$_} =~ /^Newly/ ) { print "Added $_;"; } else { print "Delete $_"; } }
}
--
Jay "Yohimbe" Thorne, alpha geek for UserFriendly