[quote user="David Harris"]
You are welcome to suggest extensions to the existing regex engine, though - I will consider any reasonable request if it is feasible and can be done without creating significant backwards-compatibility problems.
[/quote]

I suggest this: http://www.regexpstudio.com/

 Cheers!

Hi,

I am missing some more metacharacters for regular expressions known from Linux like whitespace-characters, non-whitespace-characters etc.
Was it possible to add those?

Thank you, Rainer

The regular expression engine in Pegasus Mail and Mercury considerably pre-dates almost all of the Linux implementations, which means that it has legacy issues (i.e, it is so widely-used that I can't easily change it without invalidating many, many sites' data).

I *did* expand the regex format a few years back, to include various whitespace metacharacters (/w and /W in particular), but things like "start of line" and "end of line" aren't directly supported because the engine makes them explicit (as a general rule, all matches inherently start at the beginning of a line and end at the end of a line).

Moving to a different regex format would not be a trivial task - it would require fundamental changes in the way many features in Pegasus Mail and Mercury operate, and would invalidate every current expression stored by any Pegasus Mail or Mercury user.

You are welcome to suggest extensions to the existing regex engine, though - I will consider any reasonable request if it is feasible and can be done without creating significant backwards-compatibility problems.

Cheers!

-- David --

Hi David,

and thanks for your reply.
In the meantime I found a help page to content control mentioning more metacharacters (not in help index when you look for "regular"). These were enough for my use.
Not all work in all places BTW (/x does not in transaction filtering).

 Thank you, Rainer