From: William James <w_a_x_man@...>
Date: 2006-11-25T04:48:23+09:00
Subject: Re: Ruby with regular expression

peppermonkey wrote:
> Hi,
>   I'm new to Ruby (and Regular expressions in general) and as such,
> this is rather a newbie question but I'm trying to write a script in
> Ruby to open a file and do some string manipulation.
> Basically I'm getting hung up with regular expressions.
> Suppose there is a file that contains, among other lines, lines of the
> following structure.
>
> "This [1234567890] points to [0987654321]"
>
> Assume the line structure (words, spaces etc.) stay constant.
> The actual numbers (within the brackets) are not constant.
> There is always 10 numbers within the brackets.
> There are other lines that have numbers enclosed by '[',']' that must
> be left alone.
>
> How can you replace only those numbers in the above structure to
> "xxxxxxxxxx"?
> Openning a file, searching the file, writing to the file I'm presuming
> is simple but the expression to identify and then replace those numbers
> are giving me problems. Any help would be greatly appreciated.
>
> Thank you.

This will modify the original file and create a backup file.
(And it should be a single line.)

ruby -i.bak -pe"sub(/This \[\d{10}\] points to \[\d{10}\]/, 'This
[xxxxxxxxxx] points to [yyyyyyyyyy]')" myfile