From: Ross Bamford <rosco@...>
Date: 2006-01-05T02:27:59+09:00
Subject: Re: Searching a file for keywords?

On Wed, 04 Jan 2006 15:55:18 -0000, Steve Starr <comtux@gmail.com> wrote:

> I am trying to find out how to search a file and find certain key words
> then print them.
>
> Example:
>
> #!/usr/bin/ruby
>
> system("cat /proc/partitions > drives.txt")
>
>
> Output:
>    8     0    1007616 sda
>    8     1    1007600 sda1
>    3     0   33027622 hda
>    3     1   14651248 hda1
>    3     2   14651280 hda2
>    3     3    3719047 hda3
>
> Now i would just want to print the word hda to the screen.
>
> Any help would be nice.
> Thanks
>

Maybe:

	File.open('/proc/partitions') do |f|
	  f.each_line do |s|
	    puts s if s =~ /hda/

	    # Or do you mean:
	    # s.scan(/hda/) { |it| puts it }
	    # ?
	  end
	end

Or:

	File.open('/proc/partitions') do |f|
	  puts f.grep(/hda/)
	end

Alternatively, here's a use for that wierd gets behaviour people are  
talking about, and those hateful Perl-type shortcuts:

	$ ruby -ne 'print if ~/hda/' /proc/partitions

(effectively same as)

	$ ruby -e 'while gets; print if ~/hda/; end' /proc/partitions

(I assume you already know about the tools that are provided for this  
outside Ruby).

-- 
Ross Bamford - rosco@roscopeco.remove.co.uk