# Want to compare data in two files

**URL:** <https://www.ruby-forum.com/t/want-to-compare-data-in-two-files/146513>\
**Category:** Ruby\
**Created:** [August 21, 2008, 10:05pm UTC](https://www.ruby-forum.com/t/want-to-compare-data-in-two-files/146513 "2008-08-21T22:05:31Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [August 21, 2008, 10:05pm UTC](https://www.ruby-forum.com/t/want-to-compare-data-in-two-files/146513/1 "2008-08-21T22:05:31Z")

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I have two CSV files and i want to find the duplicates records.

For ex.

Sheet1 Sheet2  
Vipul Anthony  
John Wayne  
Mac Bill  
smith randy  
Nick thalia  
Trishi  
ricky  
sachin  
Nick

So i want to check the appearance of each record of Sheet1 in the  
sheet2, like i want to check if vipul exist in sheet2 or not.

Is there any automated tool for it or do i have to do it manually.

Thanks in advance.

Vipul jindal

---

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**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [August 21, 2008, 10:33pm UTC](https://www.ruby-forum.com/t/want-to-compare-data-in-two-files/146513/2 "2008-08-21T22:33:38Z")

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On 21.08.2008 22:02, removed\_email\_address@domain.invalid wrote:

> ```
> Trishi
> ricky
> sachin
> Nick
> 
> ```
> 
> So i want to check the appearance of each record of Sheet1 in the  
> sheet2, like i want to check if vipul exist in sheet2 or not.
> 
> Is there any automated tool for it or do i have to do it manually.

Not sure what you want (or rather, why you are asking here if you just  
want a quick solution) but there is of course

> > diff -u \<(sort Sheet1) \<(sort Sheet2)

Note, you need a decent shell and OS for this (bash on Linux will do).  
Otherwise you need temporary files.

Cheers

robert

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**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [August 22, 2008, 2:52am UTC](https://www.ruby-forum.com/t/want-to-compare-data-in-two-files/146513/3 "2008-08-22T02:52:21Z")

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On Thu, Aug 21, 2008 at 1:01 PM, [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> ```
> Trishi
> ricky
> sachin
> Nick
> 
> ```

if it’s just one word per line and the files aren’t huge

a = IO.readlines(‘sheet1’)  
b = IO.readlines(‘sheet2’)  
puts a & b

martin

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**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [August 22, 2008, 6:27am UTC](https://www.ruby-forum.com/t/want-to-compare-data-in-two-files/146513/4 "2008-08-22T06:27:01Z")

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I’m not a master of the language yet, but based on what I’ve learned,  
can’t you create two arrays out of those files, let’s say sheet1,  
sheet2.  
Then simply do a “sheet2 - sheet1”

~Mayuresh

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**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [August 22, 2008, 9:22am UTC](https://www.ruby-forum.com/t/want-to-compare-data-in-two-files/146513/5 "2008-08-22T09:22:33Z")

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To identify duplicates the ‘array1 & array2’ solution given above is  
perfect. See examples below:

# setting up two arrays with your names

irb(main):004:0\> sheet1 = %w[vipul john mac smith nick]  
=\> [“vipul”, “john”, “mac”, “smith”, “nick”]  
irb(main):005:0\> sheet2 = %w[anthony wayne bill randy thalia trishi  
ricky sachin nick]  
=\> [“anthony”, “wayne”, “bill”, “randy”, “thalia”, “trishi”, “ricky”,  
“sachin”, “nick”]

# finding common elements, note the order is inconsequential

irb(main):006:0\> sheet2 & sheet1  
=\> [“nick”]  
irb(main):007:0\> sheet1 & sheet2  
=\> [“nick”]

# Determining what items are unique to the first array. (What items

are in the first list that are not in the second?) Note order matters  
here.  
irb(main):008:0\> sheet2 - sheet1  
=\> [“anthony”, “wayne”, “bill”, “randy”, “thalia”, “trishi”, “ricky”,  
“sachin”]  
irb(main):009:0\> sheet1-sheet2  
=\> [“vipul”, “john”, “mac”, “smith”]  
irb(main):010:0\>

-Tim