From: Li Chen <chen_li3@...>
Date: 2006-11-05T02:18:00+09:00
Subject: Re: How could I do this search using .scan - I am a newbie

Kevin Stolt wrote:
> Thx for ur help....but this is just searching for 'rat' isn't it?
> thats not going to work>
> 
> what I am looking is to find anything in the second column. I am not 
> sure how to explain otherwise.....
>>> I am new to ruby and I have been search and pulling my hair to do this 
>>> using .scan?
>>> 
>>> I have file which contains.....(this is an example)
>>> 
>>> bat rat cat mat pat
>>> mat sat put tomorrow today
>>> 

I assume you read a big file called test.txt  with many lines in this 
format
...
A B C D E F...
1 2 3 4 5 6 ...
11 22 33 44 55 66 ...
...

Each line is separated with \t (or whatever)

Then you want to get everything from the second cloumn such as
B 2 22,.. and put them to screen

Here we go:

###file_read1.rb


require 'enumerator'

file_name='test.txt'
result=Array.new

##append second column into an array
File.open(file_name).each do |line|
         result <<line.chomp.split(/\t/)[1]
end

#print the result in 6 columns/row separated by \t using nested 
iterators
result.each_slice(6) do|slice|
         slice.each{|element|print "#{element}\t"}
         puts
end


###output
>ruby read_file1.rb
1	2	3	4	5	6
7	8	9	10	11	12
13	14	15	16	17	18
19
>Exit code: 0



########test.txt#######
A	1	C	D	E	F
1	2	3	4	5	6
a	3	c	d	e	f
A	4	C	D	E	F
1	5	3	4	5	6
a	6	c	d	e	f
A	7	C	D	E	F
1	8	3	4	5	6
a	9	c	d	e	f
A	10	C	D	E	F
1	11	3	4	5	6
a	12	c	d	e	f
A	13	C	D	E	F
1	14	3	4	5	6
a	15	c	d	e	f
A	16	C	D	E	F
1	17	3	4	5	6
a	18	c	d	e	f
A	19	C	D	E	F



#######

What is the differnce between Perl and Ruby?
In Perl you need to do many things by yourself but in Ruby you just tell 
it what you want and Ruby does it for you :)

Li

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