From: Robert Klemme <shortcutter@...>
Date: 2009-12-20T21:50:09+09:00
Subject: Re: how to put unique lines from regexped file

On 20.12.2009 12:50, beny 18241 wrote:
> beny 18241 wrote:
>> Hi all,
>>
>> I have such a question, when i open a file doing some grep stuff...
>>
>> ---
>> File.open('aa.xml').each do |line|
>> dev_name = ARGV[1]
>>         if line =~  /<prf:CcppAccept>/..line =~  /<\/prf:CcppAccept>/
>>                 if line =~ /<rdf:li>(image|audio|video).*<\/rdf:li>/
>>         line.gsub('<rdf:li>image/jpeg', "INSERT INTO VMPOLICY_VALUES
>> VALUES(\'#{dev_name}\',\'jpginpage\',\'true\',\'#{$ver}\')")).gsub(
>> "<\/rdf:li>", ";").each do |ss|
>> ----
>>
>> I recive output like
>>
>> INSERT INTO TABLE VALUES(1,1,1)
>> INSERT INTO TABLE VALUES(1,2,2)
>> INSERT INTO TABLE VALUES(1,1,1)
>>
>> now  i wanted to put only that lines which are uniqe...
>> INSERT INTO TABLE VALUES(1,1,1)
>> INSERT INTO TABLE VALUES(1,2,2)
>>
>>
>>  how i can do this ??
>>
>> i thought about...
>>
>> puts ss.unque
>>
>> but its dont work
>>
>>
>> Please Help
>>
>> Regards
>> beny18241
> 
> 
> ok i figure it out :)
> 
> puts ss unless ss == @prev; @prev = ss

That works only if the input is ordered.  For unordered input here's an 
efficient way:

require 'set'

unique = Set.new

File.foreach('aa.xml') do |line|
   x = ... line ...
   puts x if unique.add? x
end

Of course you can also use a Hash for this.

unique = {}

File.foreach('aa.xml') do |line|
   x = ... line ...

   unique.fetch x do
     unique[x] = true
     puts x
   end
end

Btw, since your input appears to be XML it's probably a better idea to 
process it with XML tools like REXML and the like.

Kind regards

	robert

-- 
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