From: Robert Klemme <shortcutter@...>
Date: 2008-11-17T04:56:43+09:00
Subject: Re: gsub and reg expressions

On 16.11.2008 20:00, Stuart Clarke wrote:
> I have a field full of data and therefore I am using a regular
> expression to extract one part of it -  #{event.description[/Logon
> Type:\t2/]}
> 
> This works fine. I want to now add in gsub to replace 'Logon Type: 2'
> with the string 'Local Logon' - #{event.description.gsub([/Logon
> Type:\t2/], 'Local Logon')}

As others have pointed out you are mixing up String#[] with String#gsub.

Note, that you can do replacements with String#[]= like this:

irb(main):001:0> s = "foo bar Logon Type:\t2 baz"
=> "foo bar Logon Type:\t2 baz"
irb(main):002:0> puts s
foo bar Logon Type:     2 baz
=> nil
irb(main):003:0> s[/Logon Type:\t2/] = 'Local Logon'
=> "Local Logon"
irb(main):004:0> s
=> "foo bar Local Logon baz"
irb(main):005:0> puts s
foo bar Local Logon baz
=> nil

The "classic" version of course would be

irb(main):006:0> s = "foo bar Logon Type:\t2 baz"
=> "foo bar Logon Type:\t2 baz"
irb(main):007:0> s.gsub /Logon Type:\t2/, 'Local Logon'
=> "foo bar Local Logon baz"

Note that in your case String#sub might be sufficient.  Alternatives are 
String#sub! and String#gsub! which you can use if you do not want to 
retain the original string.

Cheers

	robert