how to compare 2 very large textfiles

[dunbarx at aol.com]

Pete.


Lovely and compact. If there is one thing that LC does that HC could only draem of, at least as regards raw processing power, it is arrays.



Craig newman


-----Original Message-----
From: Pete <pete at mollysrevenge.com>
To: How to use LiveCode <use-livecode at lists.runrev.com>
Sent: Wed, Oct 5, 2011 3:15 pm
Subject: Re: how to compare 2 very large textfiles


I've used an array to do this type of operation in the past.  Haven't tried
this code but it might work better.

repeat for each line i in tTextA
put true into myArray[i]["A"]
end repeat

repeat for each line i in tTextB
put true into myArray[i]["B"]
end repeat

repeat for each line k in the keys of myArray
if myArray[k]["A"] is not true then put k & return after after tMissingInA
if myArray[k]["B"] is not true then put k & return after after tMissingInB
end repeat

Pete
Molly's Revenge <http://www.mollysrevenge.com>




On Wed, Oct 5, 2011 at 3:00 PM, Matthias Rebbe <
matthias_livecode_150811 at m-r-d.de> wrote:

> Hi,
>
> i need to compare two very large text files with about 5000 - 7000 lines
> each with a lines size of up to 256 chars.
>
> I need to find out if there are lines missing in either file a or file b.
>
> What is the best way to do this with good speed?
>
> I tried to check each line in file a and if the line is in file b.
> And after that, i check for each line in file b and try to find out
> if the line is in file a.
>
> With large files it takes about 10 to 15 minutes to do the complete check.
>
> My script looks like this
>
> repeat for each line i in tTextA
> if i is not among the lines of tTextB then put i &return after tMissingInB
> end repeat
>
> repeat for each line i in tTextB
> if i is not among the lines of tTextA then put i &retrurn after tMissingInA
> end repeat
>
> Is there a better (faster) way?
>
> Regards,
>
> Matthias
>
>
>
>
>
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