# Re: help regarding extracting a particular value in a file

**URL:** <https://www.ruby-forum.com/t/re-help-regarding-extracting-a-particular-value-in-a-file/61703>\
**Category:** Ruby\
**Created:** [May 26, 2006, 10:28am UTC](https://www.ruby-forum.com/t/re-help-regarding-extracting-a-particular-value-in-a-file/61703 "2006-05-26T10:28:29Z")\
**Posts on this page:** 2\
**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:** [May 26, 2006, 10:28am UTC](https://www.ruby-forum.com/t/re-help-regarding-extracting-a-particular-value-in-a-file/61703/1 "2006-05-26T10:28:29Z")

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Assuming that your data is in a file “data\_to\_split.txt” in the same  
directory,  
you can do this:

file\_name=“data\_to\_split.txt”  
data\_array=IO.readlines(file\_name) # reads content of file into an  
Array (  
each entry = one line)  
only\_second\_entries=[]  
data\_array.each{|line|  
only\_second\_entries\<\<(line.split(‘,’)[1]) # note that indices start at  
0 in  
Ruby  
}  
p ‘only second entries contains’  
p only\_second\_entries

If you have more complicated patterns that separate your data than just  
a  
comma,  
you can also use split in conjunction with “regular expressions”.

```
      only_second_entries<<(line.split(/,/)[1]) # note that indices

```

start at 0 in Ruby

These “regular expressions” allow to search for things like “a comma and  
then two small letters, followed by at least three numbers and then  
anything but  
“A””, so there is  
room for arbitrary complexity …  
Regular expressions are explained in detail here:

\_[http://www.regular-expressions.info/\_](http://www.regular-expressions.info/_)  
([http://www.regular-expressions.info/](http://www.regular-expressions.info/))

Best regards,

Axel

---

<div class="post-metadata">

**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:** [May 26, 2006, 11:02am UTC](https://www.ruby-forum.com/t/re-help-regarding-extracting-a-particular-value-in-a-file/61703/2 "2006-05-26T11:02:28Z")

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Hi Nuralanur

Thanks for your reply and help.  
My data.txt file contains data like

p1,p2,p3  
c1,c2,c3

I did try your code.Its giving output  
p2  
c2

but i want to retrieve a single value like p2(2nd value of 1st row ) or  
c3  
(3rd value of 2nd row)only.

Thanks in advance  
Tanushree