match a certain line of text - having probs with finding correct regex syntax

Posted by Dakine on Sun 19 Apr 2015 05:27 PM — 7 posts, 28,892 views.

Dakine Sun 19 Apr 2015 05:27 PM #0

I'm trying to match as an example the following line of text via a trigger.

(13) (M)(G)(H) Ice Cold Arnold Palmer (120)

The first set of brackets can be in the format as
( 1) or (10) or absent. The number of potions.

second set of brackets "(M)(G)(H)" can be any combination e.g (M)(G) or (M) or (G) etc.

The name (Ice Cold..) I have put into a variable to match.

The last bracket will always be present and will be any number up to 201.

Currently I've got it to match too many things or nothing at all.

I have the following so far. I've tried using various online regex sites to decode it but end result is a headache.

to match: (13) (M)(G)(H) Ice Cold Arnold Palmer (120)


^\s*\((\s\d|\d*)\)\s(?:\((\w+)\)\s)*(@!variable)\s\((.*)\)$

Any help would be appreciated.

Thanks
Dak

Nick Gammon Australia Forum Administrator Sun 19 Apr 2015 07:51 PM #1

It would help to post the whole thing, so we can check if things like "expand variables" are checked.

For advice on how to copy aliases, timers or triggers from within MUSHclient, and paste them into a forum message, please see Copying XML.

Nick Gammon Australia Forum Administrator Sun 19 Apr 2015 08:16 PM #2

This works as far as I can tell:


<triggers>
  <trigger
   custom_colour="2"
   enabled="y"
   expand_variables="y"
   match="^\s*(\(\s?\d+\)){0,1}\s+((\([MGH]\)){0,})\s*@variable\s+\((\d+)\)$"
   regexp="y"
   send_to="2"
   sequence="100"
  >
  <send>
%%1 = %1
%%2 = %2
%%3 = %3
%%4 = %4
</send>
  </trigger>
</triggers>

Output:


%1 = (13)
%2 = (M)(G)(H)
%3 = (H)
%4 = 120

Explanation with each part labelled:


^\s*(\(\s?\d+\)){0,1}\s+((\([MGH]\)){0,})\s*@variable\s+\((\d+)\)$
 1  2 3 4  5 6 7  8  9  a bc  d   ef  g h i  j        k  Lm n p q

1 = zero or more spaces
2 = start of group
3 = opening bracket in text
4 = optional space
5 = one or more digits
6 = closing bracket in text
7 = end of group
8 = group can occur 0 or 1 times
9 = one or more spaces
a = start of group of one or more of (G)(M)(H)
b = start of group of a single (G) or (M) or (H)
c = opening bracket in text
d = set consisting of M or G or H
e = closing bracket in text
f = end of group of a single (G) or (M) or (H)
g = previous group can occur 0 or more times
h = end of group of one or more of (G)(M)(H)
i = zero or more spaces
j = the variable "variable" expanded
k = one or more spaces
L = opening bracket in text
m = start of group
n = one or more digits
p = end of group
q = closing bracket in text

Dakine Sun 19 Apr 2015 08:37 PM #3

Yes, sorry should have done that for clarity.


<trigger
   enabled="n"
   expand_variables="y"
   ignore_case="y"
   make_italic="y"
   match="^\s*\((\s\d|\d*)\)\s(?:\((\w+)\)\s)*(@variable)\s\((.*)\)$"
   name="LocatePots"
   regexp="y"
   script="PotsFound"
   sequence="50"
  >
  </trigger>


function PotsFound(sName,sLine,wildcards)
    debug("triggered potsFound")
end -- PotsFound

The trigger is sound in terms of it firing if the pattern was matched. I've tested it with a simple match without a variable to confirm.
Also that the @variable is actually being expanded. I've confirmed this with a simple trigger that sent the expanded variable to the output.

The regex pattern isn't quite right having tried it with a online pattern tester. I've tested it by replacing the variable with the actual text and no luck. It only succ

Also i realised that I posted the match with a missing escape character for one of the brackets. This was a typo and not in the code. I've edited the original post.

Dakine Sun 19 Apr 2015 08:44 PM #4

Quote:


<triggers>
  <trigger
   custom_colour="2"
   enabled="y"
   expand_variables="y"
   match="^\s*(\(\s?\d+\)){0,1}\s+((\([MGH]\)){0,})\s*@variable\s+\((\d+)\)$"
   regexp="y"
   send_to="2"
   sequence="100"
  >
  <send>
%%1 = %1
%%2 = %2
%%3 = %3
%%4 = %4
</send>
  </trigger>
</triggers>

Wow that's awesome. You find a solution in minutes that's literally taken me hours with no result.
Any secrets to a better understanding of regex? I'm not exactly a novice to it but often hard to see the wood for the trees..
That explanation you provided does give you an 'Oh now is see' moment..
What I should have done on reflection is broken it down more and tested for the different parts.

Thank you Nick

Nick Gammon Australia Forum Administrator Sun 19 Apr 2015 09:44 PM #5

Regular expressions

Regular expressions (as used in triggers and aliases) are documented on the Regular expression tips forum page.
Also see how Lua string matching patterns work, as documented on the Lua string.find page.

What I do when I am struggling with a complicated regexp is to start small and build up.

So for example with yours, make it colour the matching line, echo the wildcards (like I did) and then start from the left.

So for example, get it to match:


(13)

Then:


(13) (M)(G)(H)

Then add the item name, and so on. By leaving off the trailing $ it will match providing the start is right.

If you try to match the whole thing at once a space out of place can cause the whole thing to fail.

Dakine Sun 19 Apr 2015 09:53 PM #6

Yes that makes a lot of sense. Thanks for the solution and pointers.

Dak