From: William James <w_a_x_man@...>
Date: 2006-11-19T11:25:05+09:00
Subject: Re: How to use regexp to replace character with backslash plus this character

Paul Lutus wrote:
> Maciej Pilichowski wrote:
>
> > Hello,
> >
> >   1.8.5.
> >
> >   I want to 'correct' filenames for unix shell so I want to preceed
> > any let's say & with backslash. Here is code translated from my
> > original script in Perl -- end of the function
> >
> >   return filename.gsub(/([\;\!\&\%\$\' ])/,'\\\1')
> >
> > However it doesn't do anything good. If I put space in the middle
> > \\ \1
> >
> >   the replacament is correctly recognized. But I don't want to use
> > space in the middle. What's wrong here?
>
> -------------------------------
> #!/usr/bin/ruby -w
>
> data = ";!&%$"
>
> data.gsub!(%r{([;!&%$' ])},'\\\\\1')
>
> puts data
> -------------------------------
>
> Output:
>
> \;\!\&\%\$

irb(main):055:0> puts ";!&%$".gsub( /[;!&%$]/, '\\\\\&' )
\;\!\&\%\$

irb(main):008:0> puts ";!&%$".gsub( /[;!&%$]/ ){ "\\" + $& }
\;\!\&\%\$

irb(main):009:0> puts ";!&%$".gsub( /[;!&%$]/ ){ "\\#{ $& }" }
\;\!\&\%\$

irb(main):011:0> puts ";!&%$".gsub( /([;!&%$])/ ){ "\\#{ $1 }" }
\;\!\&\%\$