[Exim] Need Exim Filter Help - Willing to Pay - Smart Readfi…

There's $100 by PayPal in this fopr whoever solves this problem for me.
The first one who makes this work the best gets the money. If I use code
snippits out of other people's solution I'll give an extra $20 to the
other person I used a snippet from. And - I will share the solution for
free with everyone.

I just really need this.

Here what I need. I need to be able to read a text file containing
regular expressions on separate lines and turn the results into a big OR
regular expression. In other words - A file that looks like this:

String1
String2
String3

becomes (String1|String2|String3)

This code almost works:

if "$h_received:" matches "${readfile{/etc/exim/blockhosts}{|}}"
then
Add some header
endif

But - where it fails is - if there is a newline at the end it returns a
final | which kills it. Similarly - a blank line returns || in the
middle which also kills it.

It can't return (String1|String2||String3|)

The Solution seems to be applying ${sg} to the results and I have tried
that and came very close to actually working. But due to "" and multiple
levels of escaping I just gave up in frustration. Sometimes I'm just not
very good at this.

The part I need for you to write and test to make sure it works is the
part after "matches".

At a minimum, it can't return anything with a trailing "|" or a "||" in
the middle. Thus blank lines or lines that look blank (spaces ot tabs
only) have to be ignored.

Ideally - Lines that start with # would also be ignored.

A test file would look like this:

farm.*sex
^.*porn-site1
^.*porn-site2
# Comment to ignore followed by a blank line to also ignore

spam-site1
^.*spam-site2
^.*spam-site[0-9]{1,3}
#End - this line is ignored

So - who wants to make a little money and get this working? Here's some
of the code snippits that I was sent a long time ago when I last gave up:

${sg{                                outer sg
    ${sg{                              inner sg                 ) operand
        ${readfile{/file}{|}}          operand for inner sg     )   for
        }                              end of operand           )  outer
        {\\|\$}                        match | at end           )    sg
        {}                             replace with nothing     )
     }                                 end of inner sg          )
    }                                end operand for outer sg
    {\\|\\|}                         match ||
    {|}                              replace with |
 }

if "${local_part:$h_From:}@${domain:$h_From:}" matches "${sg\
   {${sg\
      {${readfile{/etc/exim/x}{|}}}\
      {#.*?\\\\|}\
      {}\
      }}\
   {(\\\\|)\\\\|}\
   {$1}\
}"
then
endif