Replace and inserting strings within .txt files with the use of regex

[Νίκος]

On 8 Αύγ, 11:09, Steven D'Aprano <st... at REMOVE-THIS-
cybersource.com.au> wrote:
> On Sat, 07 Aug 2010 17:20:24 -0700, Νίκος wrote:
> > I don't know how to handle such a big data replacing problem and cannot
> > play with fire because those 500 pages are my cleints pages and data of
> > those filesjust cannot be messes up.
>
> Take a backup copy of the files, and only edit the copies. Don't replace
> the originals until you know they're correct.
>
> --
> Steven

Yes of course, but the code that John S provided need soem
modification in order to be able to change various instances of php
tags and not only one set.