From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2008-05-29T18:02:51+09:00
Subject: Re: Strings, postgresql and gsub

On Thu, May 29, 2008 at 10:47 AM, J-H Johansen <ondemannen@gmail.com> wrote:
> Hi,
>
> I'm somewhat stumped at the moment due to problems with inserting
> strings in postgresql containing 's.
>
> Normally, I'd just add a \ to escape the ' and everything would be just fine.
> But for some reason, Ruby won't let me do this.
>
>
> ruby 1.8.6 (2007-09-24 patchlevel 111) [i686-linux]
>
> irb(main):033:0* s = "blah'blah"
> => "blah'blah"
> irb(main):034:0> s.gsub(/'/, "\\'")
> => "blahblahblah"
> irb(main):035:0> s.gsub("'", "\\'")
> => "blahblahblah"
>
>
> I've seen myself blind on this one ...and I still can't see where the
> problem is. Any clues ?

This use of gsub processes the escaping of the sub string twice,
the Ruby one for the literal string and a second one for backreferences,
so you'll need:

irb(main):001:0> a = "blah'blah"
irb(main):002:0> a.gsub("'", "\\\\'")
=> "blah\\'blah"
irb(main):005:0> a.gsub("'", "\\\\'").length
=> 10

Hope this helps,

Jesus.