# Beginner gsub and ri questions

**URL:** <https://www.ruby-forum.com/t/beginner-gsub-and-ri-questions/57997>\
**Category:** Ruby\
**Created:** [April 17, 2006, 5:39pm UTC](https://www.ruby-forum.com/t/beginner-gsub-and-ri-questions/57997 "2006-04-17T17:39:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jamal86](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ebca7d/32.png) [@jamal86](https://www.ruby-forum.com/u/jamal86)\
**Post date:** [April 17, 2006, 5:39pm UTC](https://www.ruby-forum.com/t/beginner-gsub-and-ri-questions/57997/1 "2006-04-17T17:39:21Z")

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How can I do a case-insensitive global substitution? Suppose, for  
example, a string contained occurences of DOG, Dog, dog, and mistyped  
dOg. I want every instance to be replaced by cat (without having to  
test for each case permutation).

How can I generate a large text file containing all ri documentation  
available on my system? I would like the topics to be in as logical an  
order as possible, and in alphabetical order otherwise. I would like to  
place a \r\n\f\r\n sepearater sequence between each topic.

Jamal

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**Author:** ![jamal86](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ebca7d/32.png) [@jamal86](https://www.ruby-forum.com/u/jamal86)\
**Post date:** [April 17, 2006, 6:25pm UTC](https://www.ruby-forum.com/t/beginner-gsub-and-ri-questions/57997/2 "2006-04-17T18:25:49Z")

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“DOG” =~ /dog/i