Lua Pattern Matching

Question

I have a file that I get from pulling out values from a Microsoft Lync conversation that has RTF formatting tags. An example file would be like:

{\rtf1\fbidis\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fcharset0 >Segoe UI;}{\f1\fnil Segoe UI;}} {\colortbl ;\red0\green0\blue0;} {*\generator Riched20 15.0.4420}{*\mmathPr\mwrapIndent1440 }\viewkind4\uc1 \pard\cf1\embo\f0\fs20 Craig...\embo0 \embo please\embo0 \embo close\embo0 \embo >out\embo0 \embo of\embo0 \embo your\embo0 \embo old\embo0 \embo client\embo0 \embo >and\embo0 \embo re-open\embo0\f1\par {*\lyncflags rtf=1}}

Using Lua scripting I'm trying to remove the RTF tags and just pull out the text of the conversation. So the result of my function should be:

Craig... please close out of your old client and re-open

I've tried using a string.gsub with a regex to match the patterns and replace them with a blank space to only leave the text but it's not working. Here is the code that I have so far for the string.gsub:

result = string.gsub(s, "\{\*?\\[^{}]+}|[{}]|\\\n?[A-Za-z]+\n?(?:-?\d+)?[ ]?", " ")

Any suggestions would be greatly appreciated!

Additional:

[email protected] @ 2013-01-18 17:48:03Z (TO: [email protected])

{\rtf1\fbidis\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fcharset0 Segoe UI;}{\f1\fnil Segoe UI;}} {\colortbl ;\red0\green0\blue0;} {*\generator Riched20 15.0.4420}{*\mmathPr\mwrapIndent1440 }\viewkind4\uc1 \pard\cf1\embo\f0\fs20 works\embo0 \embo for\embo0 \embo me..\embo0 \embo how\embo0 \embo about\embo0 \embo embedding\embo0 \embo pictures?\embo0\f1\par {*\lyncflags rtf=1}}

[email protected] @ 2013-01-18 17:48:57Z (TO: [email protected])

{\rtf1\fbidis\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fcharset0 Segoe UI;}{\f1\fnil Segoe UI;}} {\colortbl ;\red0\green0\blue0;} {*\generator Riched20 15.0.4420}{*\mmathPr\mwrapIndent1440 }\viewkind4\uc1 \pard\cf1\embo\f0\fs20 I\embo0 \embo see\embo0 \embo it\embo0\f1\par {*\lyncflags rtf=1}}

[email protected] @ 2013-01-18 17:49:27Z (TO: [email protected])

{\rtf1\fbidis\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fcharset0 Segoe UI;}{\f1\fnil Segoe UI;}} {\colortbl ;\red0\green0\blue0;} {*\generator Riched20 15.0.4420}{*\mmathPr\mwrapIndent1440 }\viewkind4\uc1 \pard\cf1\embo\f0\fs20 let's\embo0 \embo try\embo0 \embo a\embo0 \embo meeting.\embo0\f1\par {*\lyncflags rtf=1}}

Welcome to StackOverflow! What output does the regex you've given result in? — andrewdotnich
If in the end you are still not satisfied with the pattern matching solution you might want to check you the lpeg library — hugomg

Paul Kulchenko Paul Kulchenko · Accepted Answer · 2013-02-04T22:37:09

Lua patterns don't have or operators (|) or optional groupings ((?:...)?). Something like this may work:

s:match("{(.+)}"):gsub("%b{}", ""):gsub("\\%w+", "")

will return:

"    Craig...  please  close  >out  of  your  old  client  >and  re-open "

First gsub removes all pairs of {} along with their content, the second gsub removes all rtf tags (although there seem to be some that allow spaces in them, so you may need to tweak the pattern).

Lua Pattern Matching

2 Answers