From: Garthy D <garthy_lmkltybr@...>
Date: 2012-04-16T16:56:01+09:00
Subject: Re: insert text after line "whatever"


Hi fox,

On 16/04/12 15:57, fox foxmaster wrote:
> Hi all,
>
> I have a problem that I am struggling with.
>
> Problem I have is that I want to insert text in a text file after a
> specific line.
>
> My thought was to copy the original file line by line and when I got to
> a specific line it would insert the text that I wanted

This sounds like the approach that I would use. Open a source file to 
read, open the destination file. Read it in a line at a time, write it 
out. Make changes as you go, adding lines, removing them, etc. At EOF, 
close both files. Remove the old source and replace with the destination 
if desired. A Variation includes holding the whole new file in memory 
and writing it out in one step at the end.

>, but I did not
> manage to do this

Do you have your attempt at this to share? Someone might be able to spot 
the problem if you post it.

> so I went another way, like this
>
>    File.open('test.bak', 'r+') do |file|
>      file.each do |line|
>        if line =~ /\<\/DHCPServer>/  #trigger
>          file.seek(-line.size, IO::SEEK_CUR)
>          file.puts ("Hello") #text to input
>        end
>      end
>    end
>
> But when I use this, first it manipulates the original file and it
> deletes some of the letter of the trigger "</DHCPServer>"
>
> So can someone guide me to the right path?
>
> Regards
> Fox
>

Garth