You might try using a diff utility, but on 5000 files that a lot of comparisons. However, most diff's do have options to allow you to ignore some whitepace and other "inconsequential" differences.

You could create an Digest::MD5 digest for each file and the compare those. If the files are identical, the md5s will be also. However, even small whitespace differences will change the outcomes, which may be too sensitive for your purpose.

I think I would try preprocessing the files to strip all the whitespace, and then produce an md5 from the results. That probably still doesn't guarentee that the files aren't the same data sets with just variations in formatting (eg. 10.0 -v- 10 -v- 1e1 etc), but it should reduce the possibilities.

Beyond that, a lot depends on the size, nature and format of the data and the reliability of your ripping process.

Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
"Memory, processor, disk in that order on the hardware side. Algorithm, algorithm, algorithm on the code side." - tachyon

In reply to Re: Verifying data in large number of textfiles by BrowserUk
in thread Verifying data in large number of textfiles by dchandler

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