[exim] exim, sg and tr

Hello,

I am using ${sg} with a multiline header, and it looks to me that
- sg compared to perl regexp is in single-line-mode "." stops at '\n'
- sg doesn't accept parameters similar to Perl's s///m

or is there some (potentionally undocumented) feature I could use (.*) to match also '\n'?

Now I am stuck at regexp similar to (.*)\n?(.*)

Ofcourse I could use ${tr} to convert '\n' to whitespace or similar.

And about ${tr} there isn't Perl-familiar squish and delete functions?