From: Rob Biedenharn <Rob@...>
Date: 2007-03-23T00:22:17+09:00
Subject: Re: Knocking Lines Out Of A Multiline String


On Mar 22, 2007, at 10:43 AM, Andrew Stewart wrote:

> Hello,
>
> What's a (good!) way to remove lines matching a pattern from a  
> multiline string?
>
> For example, I would like to remove lines matching /usr/local/lib  
> from the multiline string:
>
>     /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/ 
> action_controller/test_process.rb:382:in `process'
>     /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/ 
> action_controller/test_process.rb:353:in `post'
>     test/functional/orders_controller_test.rb:241:in  
> `test_should_handle_errors_on_edit'
>
> ...to give:
>
>     test/functional/orders_controller_test.rb:241:in  
> `test_should_handle_errors_on_edit'
>
> I tried matching the pattern-to-remove with gsub and substituting  
> an empty string, but that leaves me with lots of blank lines and  
> not really any nearer to the answer.
>
> Thanks and regards,
> Andy Stewart

 >> input = "    /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.1/ 
lib/action_controller/test_process.rb:382:in `process'
     /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/ 
action_controller/test_process.rb:353:in `post'
     test/functional/orders_controller_test.rb:241:in  
`test_should_handle_errors_on_edit'
"
=> "    /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/ 
action_controller/test_process.rb:382:in `process'\n    /usr/local/ 
lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ 
test_process.rb:353:in `post'\n    test/functional/ 
orders_controller_test.rb:241:in `test_should_handle_errors_on_edit'\n"

 >> input.gsub(%r{^.*/usr/local/lib/.*\n?},'')
=> "    test/functional/orders_controller_test.rb:241:in  
`test_should_handle_errors_on_edit'\n"


If you showed your code, an explanation could be added as to your  
regexp, but the concept certainly works as I've shown.

-Rob


Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com