Regex (TB): 1. Introduction
Whenever I came across something interesting in a mail that was created with TheBat! like „cleaned“ Subject-strings or automagically deleted PGP-lines, I would ask in one of the mailing lists: „How did you do that?“. Quite often I would receive a reply like „You will need a regex for that!“ And sometimes the result was something like:
%QUOTES="%SETPATTREGEXP=""(?is) (-----BEGIN PGP SIGNED.*?\n(Hash:.*?\n)?\s*)?(.*?) (^(- --|--\n|-----BEGIN PGP SIGNATURE)|\z)"" %REGEXPBLINDMATCH=""%text""%SUBPATT=""3"""
This is only a simple example of those cryptic looking combinations of TB!-Macros and regular expressions which are simply called „regex“ by the TB-experts. To me it seemed a random sequence of characters; as if a cat walked across my keyboard. Awkward, arbitrary and cryptic, that at least was my impression until Januk Aggarwal (special thanks to him) gave me a short introduction to regex at TBTECH and my workmate Alfred Rübartsch gave me a copy of Jeffrey Friedls excellent book „Mastering Regular Expressions“.
Although I entered the fascinating world of Regular Expression with the help of these two, I am still not an expert in the „regexian“ language. Anyway, as an advanced beginner, I have dared to write this tutorial to hopefully explain some things and give a good start in „Regular Expressions“ to other beginners.
This tutorial is meant to bring you into closer contact with the regex topic. Well, let’s see how it works; let’s see whether we will be able to explain the „regex“-example above by the time we come to the end of this tutorial.