From: JenC <jcarlile@...>
Date: 2009-03-24T23:56:57+09:00
Subject: Re: problem with gsub! in file

OK, I see now it's not trivial to read and write from a file at the
same time, and instead I should probably just drop to the command line
and call
`ruby -pe 'gsub(/foo/, "bar")' < myfile.vcproj`

When i do this, the text of the file spits out to stdio, and it
appears the substitution has been made, but when I open the file in a
text editor, it hasn't been changed.
Am I missing something?
I already checked file permissions and everything looks fine

Thanks,
Jen

`

On Mar 24, 2:33 pm, JenC <jcarl...@gmail.com> wrote:
> I am new to Ruby and trying to do a find and replace on a text file
> based on a regular expression.  When I step through the code line by
> line, it appears that the appropriate line in the file is changed, but
> when I exit the function, the file hasn't been modified.  Are in-place
> edits of files allowed? can you see what it wrong here?
>
> Here is the body of the function:
>
> def ReplaceGuid(guid)
>         r = nil
>         sconfProj = File.open("myfile.vcproj", "r+").each do |line|
>                 m = @guidExp.match(line)
>                 if !m.nil?
>                         str = m[1]
>                         r = %r{#{str}}
>                         line.gsub!(r, guid)
>                         break
>                 end
>         end
> end
>
> Many thanks,
> Jen